A forum for owners of Yamaha TTR250 trail and enduro bikes!

Members Login
Post Info TOPIC: Raid restoration


Veteran Member

Status: Offline
Posts: 74
Date:
Raid restoration
Permalink  
 


This is my Raid restoration project that has kept me busy in the evenings and weekends for the last year. The work is now finished, the bike looks good and is running well after some adjustments. I will do separate posts for the different stages of the restoration.

I bought this bike in July 2019 here in Abidjan, Cote d’Ivoire (Ivory Coast), after finally finding one for sale. This was the only one I had seen for sale in four years. I had been looking for a 250 cc off-road bike for some time, and especially a TTR 250. What I especially like: Air cooled, electric start, simple and robust construction, and a large tank on the Raid model. In addition a possibility to add a factory oil cooler and a kick start. I only wish it had valve adjustments done by a classic screw and nut method rather than these shims that need the camshafts to come off... Honda managed to do that on four valve heads on the old XR and XL models, with a single camshaft. Then again, this should not need to be done too often.

The bike I found was a white mid-1990’s Raid with the purple wheels, in a pretty rough condition. I would find out the real condition as I started taking it apart. I have repaired and restored a couple of bikes in the past, so I wasn’t too alarmed by the first impression. Maybe I should have been less optimistic.

Here are the pictures of the bike as it was when I picked it up. It looks mostly complete, the plastics look oxidized and dirty, the tank has been welded and the headlight support is bent, but otherwise looks sort of OK. It seemed to have fallen on its right hand side at some point judging from the damage.

A1.jpgA2.jpgA3.jpg

 



Attachments
__________________


Veteran Member

Status: Offline
Posts: 74
Date:
Permalink  
 

 

The wheels seem ok as well, except for two dents in the rear rim. The tank had been repaired in the past and it wasn’t pretty, but it was not leaking. The forks seemed straight.The engine ran and I could ride up and down the street to check that the gears and clutch worked OK.

A4.jpgA5.jpg



Attachments
__________________


Veteran Member

Status: Offline
Posts: 74
Date:
Permalink  
 

 

I started taking it apart with a plan to go through everything in the process, and to repaint the frame. There was some surface rust, and I definitely wanted to change the frame colour to something else.  Matter of taste. Here are some pictures taken during the disassembly and preparation for painting.

A6.jpgA7.jpg



Attachments
__________________


Super Guru

Status: Offline
Posts: 1202
Date:
Permalink  
 

Wow that tank has had a hard life!
Everything is fixable - the skill is in not spending a fortune in the process.
Good to see another resto thread. Been quiet here for a while. Keep the pics coming,
Simon.

__________________


Super Guru

Status: Online
Posts: 8349
Date:
Permalink  
 

Great pics - looks like its gonna be a good thread biggrin 

As Simon says, the forum needs a bit of spicing up wink

Brian



__________________

Exeter, Devon, UK

http://www.ttr250.com  - The one and only dedicated TTR250 FAQ! 
 

TIP: For easy viewing bookmark the "Recent Posts" view - http://ttr250.activeboard.com/p/recent/ 



Veteran Member

Status: Offline
Posts: 74
Date:
Permalink  
 

 

I don’t have access to sand blasting here, so we used a wire wheel and sandpaper to strip the frame. I used a primer from spray cans to prepare the frame for the paint and to avoid new surface rust before getting it painted.

 

A8.jpgA9.jpgA10.jpg



Attachments
__________________


Veteran Member

Status: Offline
Posts: 74
Date:
Permalink  
 

 

Painting in process in a friend’s carport. Not ideal conditions if you want a mirror finish with dust and 80% humidity, but good enough for my needs. At least there’s no risk of it being too cold for painting. The colour is a darkish silver gray, with clear coat on top. The result turned out nice and shiny. A good base to start the build-up.

 

I also painted some smaller items with spray cans.

 

A11.jpgA12.jpgA13.jpgA14.jpgA15.jpgA17.jpg



Attachments
__________________


Veteran Member

Status: Offline
Posts: 74
Date:
Permalink  
 

Next I decided to have a look at the engine for a change. The engine had seemed OK when I tested the bike before buying it, but I still decided to take off the cylinder head and cylinder to check the bore and the piston. The cylinder had been re-bored to 0.50 mm oversize, with the corresponding piston. I did a light honing of the cylinder and installed new piston rings.

A18.jpgA19.jpg



Attachments
__________________


Veteran Member

Status: Offline
Posts: 74
Date:
Permalink  
 

 

The cylinder head was not quite as good. There was an oil leak at the front where the decompressor is installed on engines with a kickstart. This had been “fixed” by covering the hole with epoxy. Still didn’t stop the leak. The inlet rubber for the carburettor  had also broken and a piece of rubber hose had been attached to the aluminium stub that remained.

H1.jpgH2.jpg



Attachments
__________________


Veteran Member

Status: Offline
Posts: 74
Date:
Permalink  
 

 

The camshafts were luckily OK, but the threads were stripped on the bolt holes for the caps, and the bolts had been tightened using small strips of aluminium in the holes to keep them tight. I repaired these with Helicoil thread inserts rather than cutting out strips from a beer can...I did struggle a bit with some of the helicoils and had to pull some out and start again, but that was just me not using the tool correctly. 

I find that using studs with a nut to tighten the cap could be a better solution. The stud would be installed once and for all in the head, and not having to screw a steel bolt in and out of the fragile aluminium threads would be a safer way to tighten the caps in place. Some engines use this solution from factory, and sometimes it is done as an upgrade on racing engines. It seems feasible to make studs that would work. Has anyone tried this? If I run into problems with these bolts again I will check with my local machine shop about doing this.

The valves were in good condition and I re-installed them after lapping them into the valve seats. I then had to shuffle around the shims and order some new ones to adjust the valve play.

H3.jpgH4.jpgH5.jpgH6.jpgH7.jpgH8.jpgH9.jpg

 



-- Edited by PurpleWheels on Tuesday 8th of September 2020 08:54:01 PM

Attachments
__________________


Veteran Member

Status: Offline
Posts: 74
Date:
Permalink  
 

 

I kept the old cam chain, but I have noticed that it’s time to replace it as well. The lines on the cam sprockets don’t quite line up, so a new chain will be on my next shopping list.

H10.jpg



Attachments
__________________


Veteran Member

Status: Offline
Posts: 74
Date:
Permalink  
 

 

Suspension was next on my list. By now I had placed my first order to Steve for parts, including bearings and seals for both front and rear suspension.

Loosening the bottom bolts/valves on the forks to take them apart was a real struggle. On one side the bolt head had been damaged due to an impact and I had to use my Dremel to open up the slot for the allen key. Even the use of a compressor driven impact gun failed to loosen the bolt. I managed to find a large 14 mm allen key and with that and an extension arm I finally managed to free up the bolts.

Next surprise was to find that both these bottom valves were damaged beyond repair. Some previous owner/mechanic had jammed a steel rod down the fork leg to keep the internals from turning when tightening the bottom bolt. Not much hope of adjusting the rebound with these. Please note that these are the early model forks, and parts are not as easy to find as they are different from all the later models.

B1.jpgB2.jpg



Attachments
__________________


Veteran Member

Status: Offline
Posts: 74
Date:
Permalink  
 

 

I took apart the forks, found the bushings and the other internals OK, cleaned everything and repainted the fork legs. Forks were put back together with new seals, although I still needed to find replacements for the bottom bolts.

The stanchions were rustfree and straight, so no worries there.

B3.jpgB4.jpg



Attachments
__________________


Veteran Member

Status: Offline
Posts: 74
Date:
Permalink  
 

 

The steering head bearings were still fine, so I cleaned and repainted the triple trees and assembled with new grease.

B5.jpgB6.jpg



Attachments
__________________


Veteran Member

Status: Offline
Posts: 74
Date:
Permalink  
 

 

By chance I found a sorry looking TTR 250 Raid behind a local motorcycle workshop, with a frame that was beyond any hope of repair but still with some good parts still on it so I bought it to use for parts. Unfortunately it was missing some of the most interesting parts like a fuel tank or the CDI, and the engine was missing the carburetor and parts of the cylinder head. However, it had good forks, with the bottom valves I needed, a nice headlight with its support, OK side covers , mudguards and seat, and various other bits and pieces that could come handy. I made sure that the guys helping me took off every nut, bolt and bracket from the frame and put these in a box I had brought. There is no way I would be able to find any replacements here, and this did really help me later.

We dragged it out from behind the workshop, took it completely apart and I loaded the parts into a taxi to get them home. Occasionally it’s a good thing that the taxi drivers here don’t care too much about the cleanliness of their vehicles, at least when you need to transport greasy motorcycle parts. Most other times you wish they did…

SP1.jpgSP2.jpgSP3.jpgSP4.jpg

 



-- Edited by PurpleWheels on Tuesday 8th of September 2020 09:01:28 PM

Attachments
__________________


Super Guru

Status: Online
Posts: 8349
Date:
Permalink  
 

What a great stroke of luck!  Some nice parts in that haul. The panels in particular are now very rare.

Loving your thread - great job and super photos biggrinbiggrin



__________________

Exeter, Devon, UK

http://www.ttr250.com  - The one and only dedicated TTR250 FAQ! 
 

TIP: For easy viewing bookmark the "Recent Posts" view - http://ttr250.activeboard.com/p/recent/ 



Super Guru

Status: Online
Posts: 2575
Date:
Permalink  
 

Very good, Simo - nice pictures and descriptions.

Something tells me you have probably done this sort of work before, maybe.

Carry on regardless - you will have a superb TTR by the time you've completed and then you'll have all the fun of getting it dirty. biggrin

Martyn.



__________________

You're never too old to learn something stupid

Budleigh Salterton. Devon



Veteran Member

Status: Offline
Posts: 74
Date:
Permalink  
 

With the frame painted I fitted the engine. Nicely tightened down I realised that I could not attach the clutch cable to the actuating arm, which was pointing in the wrong direction, and being blocked by the frame.

I have subsequently seen some warnings about this mistake, i.e. not keeping the arm pointing the right way when lifting in the engine, so I don’t feel too bad about this knowing that I wasn’t the first one. Unscrewed the bolts, tilted the engine, turned the clutch arm, and re-installed everything. Lessons learned...

F1.jpgF2.jpgF3.jpg



Attachments
__________________


Veteran Member

Status: Offline
Posts: 74
Date:
Permalink  
 

Engine and triple trees fitted, rear suspension was the next challenge. The rear swing had now a nice new coat of paint, but I had to replace all the bearings, seals and bushings in the suspension.

The bearings on the link relay arm were totally seized in place, and despite heating and soaking with WD40 it took some serious hammering to come out, piece by piece. This was a real challenge. Installing the new bearings was much easier, using a long threaded rod with large washers and suitably sized sockets.

S1.jpgS2.jpgS3.jpgS4.jpgS5.jpg



Attachments
__________________


Veteran Member

Status: Offline
Posts: 74
Date:
Permalink  
 

 

I installed a new chain slider on the swingarm and a new chain roller on the frame. Mine had been set up with some locally developed alternatives, i.e. a piece of cambelt and a rubber exhaust pipe support. Sorry, can’t confirm from which car model in case you’d be inspired to replicate this, but a mid-90’s Toyota Corolla would be a likely candidate. I also added a new frame guard where the chain could touch the frame just behind the front sprocket.

S6.jpgS7.jpgS8.jpgS9.jpgS10.jpg



Attachments
__________________


Veteran Member

Status: Offline
Posts: 74
Date:
Permalink  
 

 

The rear shock absorber cleaned up nicely, I could not see any leaks so either it’s still fine or the all the oil was lost ages ago… It went on nicely with the refurbished link arm and relay.

S11.jpg



Attachments
__________________


Veteran Member

Status: Offline
Posts: 74
Date:
Permalink  
 

 

Next in order was the electric harness that required some cleaning and repairs. I was able to take some wires from the harness I got from the parts bike, mostly to keep the correct colour coding of the wires.

There were some strange additional connections behind the headlight, and I removed the extra wiring that didn’t make any sense. Everything needed a good cleaning, but luckily nothing was badly oxidized or burned.I was quite happy with the condition of the harness.

EL1.jpgEL2.jpgEL3.jpgEL4.jpg

 

 



Attachments
__________________


Veteran Member

Status: Offline
Posts: 74
Date:
Permalink  
 

The headlight support on my bike had been damaged in an accident, although it somehow still fitted the forks. I was wondering for a while how to at least improve it knowing that these are not easy to find, yet they in some way define the Raid model. Luckily I got a good one with my parts bike, and I can keep the bent one as a project for the future. Maybe, and that could be distant...

The one on the parts bike cleaned up nicely and I installed it on the triple tree and forks. I put some tape around the stanchions to protect the chrome from being scratched by the stainless steel hose clamps.

FL1.jpgFL2.jpgFL3.jpgFL4.jpgFL5.jpg



Attachments
__________________


Veteran Member

Status: Offline
Posts: 74
Date:
Permalink  
 

 

The regulator/rectifier was another non original part, see the one on the left in the picture, and the wiring had been adapted to fit it. It looked like a part from some small Chinese bike. Would probably plug straight into the harness of an old Honda 125. I ordered a new original R/R, and found a similar faulty one here that came with the correct connector with short lengths of wiring so I could connect it to the wiring harness.

What they had done basically did work so I could have kept it, but it didn’t really fit the space under the tank and the wiring was not well done. Twisting two wires together with some tape over the wires is OK for testing, but not a permanent fix. It also looked like it may not have a sufficient output in case I would like to add any accessories later on.

RER 1.jpgRER2.jpgRER3.jpg



Attachments
__________________


Veteran Member

Status: Offline
Posts: 74
Date:
Permalink  
 

Next was installing the turn signals, which meant taking them apart, cleaning and selecting the best parts from all the ones I had from my bike and the parts bike to get a good set of four. Again removing old paint and rust, followed by repainting them.

Same story with the number plate light that I needed to open and clean. No surprise, all the bulbs had to be replaced, I don’t think there was a single working light bulb on this bike, or the parts bike for that matter. Who needs them anyhow, we have 12 hours of sun every day, all year, 6 AM to 6 PM. Riding at night is risky even with working lights.

BL1.jpgBL2.jpgBL3.jpgBL4.jpgBL5.jpg



Attachments
__________________


Veteran Member

Status: Offline
Posts: 74
Date:
Permalink  
 

 

I had two headlights to choose from, and I ended up using selected parts from both, after some cleaning and painting with a heat resistant paint.

HL1.jpgHL2.jpgHL3.jpgHL4.jpg



Attachments
__________________


Veteran Member

Status: Offline
Posts: 74
Date:
Permalink  
 

The digital speedometer needed cleaning, and the warning lamps were not working. Blown bulbs again. I got them back in service after some cleaning and replacing the bulbs, plus gluing back together the rubber bulb sockets that were falling apart.

The speedo display is a bit damaged on the lower half, see the dark shade in the picture, and it does not display any distance readings, only the speed.

Now, if you are doing 188 km/h on this bike, maybe you will not get far enough to care... no

SPE1.jpgSPE2.jpgSPE3.jpgSPE4.jpgSPE5.jpg



Attachments
__________________


Veteran Member

Status: Offline
Posts: 74
Date:
Permalink  
 

My parts bike had a good magnet for the sprocket shaft and the sensors on both bikes seem ok. I did not install the standard plastic cover, but got instead the compact metallic one from Steve. Much nicer!

The sprockets and chain are 520 instead of the original 428 on Raids. These came with the bike and were good enough for some more riding, except for a new front sprocket that I had to install. I am now riding with a 14-50 combination which seems good for off-road riding. I will probably order a 46 tooth rear sprocket to use with my spare “street” rear wheel from the spares bike.

SPE6.jpgSPE7.jpgSPE8.jpg



Attachments
__________________


Veteran Member

Status: Offline
Posts: 74
Date:
Permalink  
 

 

To my surprise the wheel bearings were still good, so I kept the old ones instead of putting in the new ones I had bought. I have a second rear wheel from my parts bike and I may want to put the bearings in that one if I decide to have a second wheel with a more street oriented tyre and sprocket on it.

I found a good second hand Continental TKC80 for the rear so that went on for now, and that will work well in off-road riding. In front I mounted a new Pirelli which is more suited for on and off road riding. The front wheel rim from the parts bike was badly corroded and badly repaired in the past, so I had to scrap it.

With the wheels on it started looking like a motorbike.

WH1.jpgWH2.jpgWH3.jpgWH4.jpgWH5.jpg



Attachments
__________________


Veteran Member

Status: Offline
Posts: 74
Date:
Permalink  
 

 

The master cylinder on my bike was from some other bike, probably a Honda street bike with a strange short lever, so I decided to replace it with a new master cylinder made for a Chinese 125 cc knock-off. Looked good and worked well with the caliper, but the lever pointed too far away from the handlebars and was awkward to use. Well, it only cost the equivalent of 5 Euros, I mean the complete master cylinder with even a brake light switch.

The master cylinder from my parts bike was not possible to repair, so I found a used master cylinder from a Yamaha TDR 125 which I cleaned up and installed. Naturally, nothing is as simple as that. One of the screws holding the top was corroded and would not come out by any means, so finally I had to drill it out and tap the hole for an M5 screw. One difference between the master cylinders is the angle of the hose banjo bolt, but it works OK. The lever I got with the master cylinder was a bit bent, but I have a new one that I can install later.

I have the extended braided hose and clutch cable from Steve, for raising the handlebars in the future. I’m 6’4” and need the extra height on my bars for standing up. I am now looking for some used Honda Africa Twin handlebars, which I should be able to find here. They are the same width, but a good 5-6 cm higher and a bit straighter, which I prefer. BTW, the Honda Transalp handlebars are an option too, same height as the AT, but they have a bit more pull-back, about the same as the original TTR handlebars.

FBR3.jpgFBR4.jpgFBR5.jpgFBR6.jpgFBR7.jpgFBR8.jpg



Attachments
__________________


Veteran Member

Status: Offline
Posts: 74
Date:
Permalink  
 

I had bought a used battery box to replace the completely destroyed one that came with my bike. They had installed a non-standard battery that was wider that the normal one, and they had cut up the battery box to make it fit. In addition, the box ended up touching the rear spring which wore away the plastic. A complete mess.

BB1.jpgBB2.jpgBB3.jpg



Attachments
__________________


Veteran Member

Status: Offline
Posts: 74
Date:
Permalink  
 

 

I could not find a correct sealed battery of the right dimensions, but one mechanic here showed me a 12V battery from an AC backup inverter, which turned out to have the exact dimensions of the original battery. Same 7 AH capacity too. These are found everywhere here due to the use of the inverters for surge protection and power cuts. The only issue was the connection as these have two narrow “spades” next to each other on top of the battery, as opposed to the usual screwed connectors. I had to turn the “top” of the battery facing rearwards, with openings made in correct positions on the battery box so I could connect the extension wires.

I had some fears about the cranking amps of these batteries, but it starts up my engine with no hesitation. Then again, I can’t say for any cold start characteristics, the average temperature here is around 28 degrees C. My other worry was about overheating the small spade connectors on these batteries, but they have been OK even after some extended cranking.

It’s not perfect as I wanted to retain the original battery cables for now, so I had to screw the original and the extension wires together on the outside of the battery box, which together with the strap I currently use hold the battery in place are too bulky to allow the side cover to fit flush. The top front of the cover does not reach the rubber grommet, but the top of the cover still fits under the seat. I will see how to improve this at a later stage, maybe with new longer cables. For now this work well for riding.

BB4.jpgBB5.jpgBB6.jpgBB7.jpg

 



-- Edited by PurpleWheels on Tuesday 8th of September 2020 08:46:03 PM

Attachments
__________________


Super Guru

Status: Offline
Posts: 1202
Date:
Permalink  
 

Aaargh, overload! You are supposed to keep us waiting weeks (sometimes months) between installments biggrin

Making a lovely job of it. Well done. The presence of not 1 but 2 Raids in Abidjan must have come as a suprise? I wonder what their back story is...

I love the timing belt swingarm protector. African solutions should not be mocked - you've got to make do with what you've got, and ingenuity is one thing African mechanics have in abundance!



-- Edited by mossproof on Tuesday 8th of September 2020 08:57:08 PM

__________________


Veteran Member

Status: Offline
Posts: 74
Date:
Permalink  
 

Hey, I just work really fast... biggrin

I agree on the ingenuity, I will share more examples of that as the story progresses! When you cannot find the right OEM part you have to take what you can find and adapt.



__________________


Super Guru

Status: Offline
Posts: 2484
Date:
Permalink  
 

Well I am enjoying reading and looking at all thissmile



__________________

totallyttrs.com

 



Member

Status: Offline
Posts: 5
Date:
Permalink  
 

Nice job! Keep us updated.



__________________


Veteran Member

Status: Offline
Posts: 74
Date:
Permalink  
 

 

I opened the carburetor for cleaning and replacing some parts that I had bought in an All Balls Racing kit. I had some trouble removing the float bowl drain screw, but I made some new grooves with a Dremel and managed to fit a flat screwdriver blade into it and unscrew it.

CB10.jpgCB11.jpgCB12.jpgCB8.jpg



Attachments
__________________


Veteran Member

Status: Offline
Posts: 74
Date:
Permalink  
 

The carburetor was dirty inside and had some issues. I replaced the float needle and filter, and the pilot jet. The emulsion tube was bent for some reason and looked old and worn, but as I could not find a replacement I just bent the head back straight.  I heated it first on the stove, screwed it back in the carburetor, and put a long 8 mm socket over it with an extension to bend it. Luckily it didn’t break off, it was far easier than I expected.

I still want to find a replacement tube as I already have replaced the needle as well. And a new main jet is also on my list.

CB3.jpgCB17.jpgCB19.jpgCB18.jpg



Attachments
__________________


Veteran Member

Status: Offline
Posts: 74
Date:
Permalink  
 

 

The accelerator pump membrane was more like a sieve, the rubber was all dried and much of it was gone. I replaced it with a new one I had ordered with the other carburetor parts.

CB15.jpgCB16.jpg



Attachments
__________________


Veteran Member

Status: Offline
Posts: 74
Date:
Permalink  
 

One float pin support post was broken and had been repaired with epoxy, which now seemed have softened. I could not find the right type of screws to repair as shown here https://ttr250.activeboard.com/t50560400/carburettor-repairing-a-broken-carburetor-float-pin-post-and/ so I decided to try something else.

I removed the old epoxy and cleaned everything. Then I drilled a small hole with a 1,2 mm drill bit through the post and filed a small groove on the top of the broken piece which had been glued back. Then I pulled a stainless steel wire through the hole and over the top and twisted the wire together. The pictures explain it better.

CB1.jpgCB23.JPGCB20.JPGCB24.JPGCB26.JPG



Attachments
__________________


Veteran Member

Status: Offline
Posts: 74
Date:
Permalink  
 

 

The pictures showed my first setup, which did interfere a little with the floats movement. I tried putting the twist on the opposite side, pointing outwards, but then the float bowl would no longer fit. In the end I twisted the two ends as in the previous pictures, but only further down, just above the hole I had drilled. That seems fine.

After that I covered the wire in new epoxy that I had tested for fuel resistance for two weeks in a glass jar filled with petrol. It did not soften at all so I assume it’ll be OK. I’m pretty confident the twisted wire won’t move, but I just wanted to have the extra support from the epoxy. I filed down the epoxy to avoid any interference with the float.

CB27.JPGCB28.JPGCB29.JPG

 



-- Edited by PurpleWheels on Friday 11th of September 2020 02:11:51 AM

Attachments
__________________


Veteran Member

Status: Offline
Posts: 74
Date:
Permalink  
 

 

My bike came with a non-original CDI, piggy backed onto the original harness. Four wires were used on this CDI as opposed to seven wires on the original. My guess is that the CDI is from some Chinese CG 125 clone. I managed to find a used TTR 250 CDI here (still can’t believe my luck!) and I wanted to put back the bike to its original setup. The bike seemed to work well with the non-original CDI, but it’s unlikely that the ignition advance curve would be identical to the original, and I had no idea about any rev limiter on this CDI.

Fortunately they had not cut all the wires, but just stripped the insulation and twisted on the additional wires for the new CDI. I took off the extra wires and put shrink tube on each original wire after disconnecting them from the CDI connector one by one. The shrink tube has glue to make it waterproof. Belts and braces...

CD1.jpgCD6.jpgCD8.jpgCD11.jpgCD12.jpgCD13.jpgCD14.jpg

 



-- Edited by PurpleWheels on Friday 11th of September 2020 12:46:39 AM

Attachments
__________________


Veteran Member

Status: Offline
Posts: 74
Date:
Permalink  
 

 

The mechanic who found the CDI (and actually sold me the bike last year) told me that I needed to replace the flywheel as well to use the original CDI. Strange..!? In fact, they had shortened the metal strip on the exterior of the flywheel which triggers the ignition, by grinding part of it off. Apparently the new CDI required this to work correctly, they had copied this from the flywheel that is used normally with these CDIs. Local ingenuity once again!

I had noticed the traces of grinding on the flywheel but had not found any explanation for it. I have learned not to question some of the things I see mechanics do here, but here they had a genuine reason for taking a grinder to a flywheel! 

I got a spare broken engine when I bought my bike, and my parts bike had a mostly complete engine too, so I had two good flywheels to choose from. Or so I thought… The threads for the flywheel puller were shot on the first engine’s flywheel so I could not screw in the flywheel puller. Luckily I have another Yamaha factory flywheel puller with three bolts that fitted into the holes on the flywheel and I could tighten the bolts to the sprag clutch behind it. Off it came, and I realised that the sprag clutch was a non-original model which had been attached by removing three of the large rivets on the flywheel center and using the holes for the sprag clutch bolts. Three 6 mm bolts, and the clutch itself was broken. Useless.

 

 



-- Edited by PurpleWheels on Friday 11th of September 2020 01:31:56 AM

__________________


Veteran Member

Status: Offline
Posts: 74
Date:
Permalink  
 

 

The second engine’s flywheel looked much better, the small flywheel puller fitted easily and the flywheel came off. However, the backside was a disaster. The sprag clutch, also a non-original, had been welded on to the flywheel, and not very professionally. No TIG weld with a nice flowing stack of coins here… Another issue could be the balancing of this setup. A few grams here and there rotating at 8000 RPM could cause some vibration.

The second picture shows the metal strip on the side of the flywheel that triggers the CDI. This has not been modified. The flywheel has some nice patina... disbelief

FW2.jpgFW3.jpgFW4.jpg

 

 



-- Edited by PurpleWheels on Friday 11th of September 2020 02:18:55 AM

Attachments
__________________


Veteran Member

Status: Offline
Posts: 74
Date:
Permalink  
 

 

To use the original CDI I still needed to find a good original flywheel, as none of these seemed fit for service. I managed to grind off the welds and remove the clutch, but the flywheel still looked a real mess.

I finally decided to take the welded flywheel to a local workshop to see if they could weld some material to the backside to replace what had been removed, and put it in a lathe to return it to the original dimensions. I brought them the other flywheel as a reference for the dimensions. They did a good job, the raised part on the repaired flywheel turned out perfect, and it only had some minor imperfections in the center where they could not remove enough material to make it totally flat. However, the sprag clutch fits flat and covers those.

These guys are professionals. They mainly work on heavy vehicles like big trucks and Caterpillars, and due to unavailability and cost of imported spares they are used to repairing anything. Luckily the owner doesn't mind occasionally helping out a biker in need. My flywheel is about the size of a wheel nut on some of his usual customer vehicles.

FW5.jpg   FW6.jpg

 



-- Edited by PurpleWheels on Friday 11th of September 2020 01:29:48 AM

Attachments
__________________


Veteran Member

Status: Offline
Posts: 74
Date:
Permalink  
 

 

I removed the flywheel from the engine on my bike and took off the sprag clutch. At that point I realised that even this was a non-original clutch, although much more like the original one. The main difference was that this clutch was attached with three 8 mm bolts, but the distance between centers fitted exactly the original holes.

I proceeded to enlarge three of the holes on my now repaired spare flywheel to 8 mm, bought three M8 x 20 allen bolts, and put everything together. The 8 mm allen bolts needed their heads to be reduced by about half a millimeter in diameter to fit the slots in the flywheel. Obviously 6mm bolts have smaller heads than the 8 mm ones. I used a grinder, rotating the bolts to keep the heads round(ish). Did some quick manicure in the process. Method not recommended in any OHS manual, better to use a file or a lathe.

Flywheel cover on, oil in the engine, connected the new CDI and it started and ran perfectly.

FW7.jpgFW8.jpgFW9.jpg

 

 

 



-- Edited by PurpleWheels on Friday 11th of September 2020 02:04:30 AM

Attachments
__________________


Veteran Member

Status: Offline
Posts: 74
Date:
Permalink  
 

 

I asked the mechanic about the origin of the sprag clutch, and it comes from a Chinese 3-wheeled tuk-tuk styled motorcycle which are popular here for transporting goods. The engine is a Zhongshen  200/250 cc, used also in other types of bikes. I found what appears to look just like mine by searching for Zhongshen 200 cc starter clutch in Google. Price $19.95.

This could be an alternative if you can’t find an original Yamaha clutch, and don’t mind a minor modification of your flywheel to fit this one. There could be others even closer to original. I did not have a choice as this was already on the bike, and I cannot find the original parts here. I even asked the mechanic to find me a second to keep as a spare since my flywheel already is adapted for these. Should I hear any funny noises coming from the sprag clutch I can just replace it. I can get ten of these for the price of one original. Time will tell how good these are, but the current one had been on the bike for some time before I bought it and works well.



__________________


Veteran Member

Status: Offline
Posts: 74
Date:
Permalink  
 

 

With my parts bike I got a small rear carrier which seemed quite OK under all the rust. I cleaned it up, straightened and painted it, and it fits the bike perfectly. I don’t know if this had been made locally or if it is something that were sold as accessories at some point. I did not find anything indicating a brand or a manufacturer. I can use it to add a small top box to store my rain gear or my helmet if I want to use this for commuting at some point. Normally I commute on my Yamaha Xmax scooter.

RR1.jpgRR2.jpgRR3.jpgRR5.jpg

 



-- Edited by PurpleWheels on Friday 11th of September 2020 02:06:25 AM

Attachments
__________________


Veteran Member

Status: Offline
Posts: 38
Date:
Permalink  
 

MACGYVER.JPGInspirational rebuild great to see the effort going in, Your new name is MacGyver



Attachments
__________________


Veteran Member

Status: Offline
Posts: 74
Date:
Permalink  
 

biggrin

Just trying to restore some Japanese ingenuity using available means. Then again, I was quite impressed by the alternative CDI solution that had been done including the modified strip on the flywheel. That takes some understanding of how these work. I kept the parts and documented how the other CDI was wired, just in case my new-old CDI would fail one day.

I was less impressed by the welded sprag clutch. no



__________________
1 2  >  Last»  | Page of 2  sorted by
 
Quick Reply

Please log in to post quick replies.



Create your own FREE Forum
Report Abuse
Powered by ActiveBoard