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Brian's 350 build
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My 350 kit 2.jpg

I have a 350 kit in my sticky mitts now and am really grateful to Simon (mossproof) who did all the hard work on getting the barrels cast and machined, the special pistons and gaskets made and building and testing the very first TTR350 in the world - cheers mate!  See here.

I have a good starting point for the build. I bought a set of empty cases from a respected member of the TTR community back in 2012 and squirrelled them away for a project and their time has now come! The engine is from a TTR that lived in Jersey and has only done 4,000 miles so the cases are in great condition and I am thinking that I will be able to re-use the bearings.

20200204_100222.jpg

I have split the cases and carefully stored the Allen bolts using a piece of card marked with their positions as shown on the right of the following photo.

20200204_101821.jpg

20200204_102936.jpg

A bit of bad luck occurred trying to remove the cross-headed bolt used to hold in the clutch actuating lever with an impact driver. The bit broke off in the bolt head no  I am pretty sure that it isn't possible to buy individual replacement bits - unless anyone knows of a source?  (EDIT - the impact driver was a kit from Halfords on a life-time guarantee and, bless their cotton socks, they replaced the broken bit for me FOC smile)

20200204_102119.jpg 

Next up is to clean up the cases and thoroughly de-greasing them. Trish is out all day tomorrow so I will have unsupervised access to the oven biggrin 

My intention is to heat the cases up in the oven, as I have done in the past, and hope most of the bearings fall out.

I just hope that I don't leave the oven smelling of burnt oil as happened the last time! disbelief

Brian



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They just don't understand, like when I clean my air cleaners in the sink !!!!!

How will the TTR350 stack up against the WR250R & or the White & red TT350, always liked the 350, I even wanted a red & black XL350 at one stage, later when I had a XR250RC my mate had a XR350 disc on the front & drum rear.

Used to be a few 350's on the market, I had a XR400 before the TTR & great engine & plenty of power but a handful.

Good luck with the build & will be interested in the ride report when it hits the road

Rds Terry

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4th Feb 2020 5.jpg

Darn it - broke the bit in my spare impact driver as well no I think the actuating lever is just going to have to stay where it is!

I have removed the transmission and gear change oil seals and will fit new in due course.

Terry - you sowed a seed there talking about cleaning parts in the sink! Despite a thorough clean in TFR, the casings still felt greasy and, to make sure I don't stink the oven out tomorrow, I have put the casings in the dishwasher on "extreme" cycle whilst TRish is out collecting the grandson from school smile

4th Feb 2020 6.jpg

I decided to use a trusted m/c engineer to bore my cases and his workshop isn't too far away. I called him this morning and, following a heart attack, he is now only working three days a week so I am not confident I am going to get my cases done any time soon. 

Brian



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Trish is out visiting today so am taking full advantage! 

I am preparing engine casings to take to Dave Massam for boring out for the 350 barrel.

So as not to stink the oven up (as happened last time I did it which got me into a bit of trouble), the cases have been through the dishwasher with extra tablets on an extreme cycle and came out a treat!

They then went in the oven at 200C for 20 minutes.  5 out of the 8 bearings dropped out easily, a couple needed a tap with a punch and one needed treatment with the internal bearing puller with slide hammer (didn't need much effort as the casing was still stinking hot!).

5th Feb 2020 1.jpg 

5th Feb 2020 2.jpg 5th Feb 2020 3.jpg

 

The trouble is that, despite looking squeaky clean, there was oil hiding in the bearing housings and the oven and kitchen now stink of burning oil no  I have left the oven and kitchen doors open and hope it goes away before Trish gets home!

So, the crankcases have been cleaned and screwed back together ready for boring. I managed to get the stubborn clutch actuating shaft retaining screw out by persuading it loose with a hammer and sharp cold chisel biggrin

 5th Feb 2020 4.jpg

Anyways up, now to get my pile of filthy oily gloves and put them through the washing machine. What could possibly go wrong?  confusebiggrinbiggrinbiggrin



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Whilst the cases are away being bored, I thought it just as well to organise the bearings and seals I would need for the rebuild. I am sure that I don't really need to replace all the bearings but, as this may be the last TTR engine I build, I am going overboard just a bit smile

The following information shouldn't be used for your own ordering purposes without checking as I cannot be held responsible for anyone ordering the wrong parts.

As I said, I may not have got this 100% correct but if Dan, Steve or Simon (who recently built their 350s) could possibly have a check through it would be greatly appreciated! smile

This first table shows the cost of the bearings and seals from your friendly Yamaha parts supplier - or Totally TTRs:

Bearings    NumberInc. VAT
Balancer bearings93306-30211was 93306-302102£50.92
Transmission output93306-20529  1£22.08
Transmission inside brg93306-20332  1£24.23
Layshaft inside brg93306-20447was 93306-204271£32.51
Layshaft o/s brg93306-00320  1£28.12
Main bearings93306-37807was 93306-378022£124.54
     Total£282.40
Seals      
Gear change oil seal93102-14209  1£6.32
Transmission shaft oil seal93102-25218was93102-252261£11.53
     Total£17.85

 

This is what the equivalent Koyo bearings would cost from Simply Bearings:

BearingsNumber      inc VAT
Balancer bearings2KOYO 6302 Open Deep Groove Ball Bearing 15x42x13mm  £11.52
Transmission output1KOYO 6205 Open Deep Groove Ball Bearing 25x52x15mm  £6.76
Transmission inside brg1KOYO 62032RS Rubber Sealed Deep Groove Ball Bearing 17x40x12mm £6.42
Layshaft inside brg1KOYO 62/22-KOY Open Deep Groove Ball Bearing 22x50x14mm £18.55
Layshaft o/s brg1KOYO 60032RS Rubber Sealed Deep Groove Ball Bearing 17x35x10mm £6.28
Main bearings2All Balls kit - 63/28 C3     £36.00
       Total£85.52
Seals        
Gear change oil seal 14x26x6mm Nitrile Rubber Rotary Shaft Oil Seal with Garter Spring R21 / SC£2.27
Transmission shaft oil seal 25x40x6mm Nitrile Rubber Rotary Shaft Oil Seal with Garter Spring R23 / TC£2.27
       Total£4.54

 

When looking up the bearing equivalents on the Simply Bearings website, I was offered the equivalent sized bearings with a "C3" reference at the same price. I rang them to ask what this meant and was told that if a bearing was going to run extremely fast and hot then these bearings were built with more clearances so could expand and not seize. I explained the application and he didn't give an opinion on whether C3 bearings would be needed and said to check the old bearing references. Having done that I can't find any with a C3 designation.

BUT, having checked my parts bin, I found a Yamaha dealer supplied bearing 93306-20427 with the Koyo reference 62/22-9C3 on (see below) so I am now a bit stumped. Also, the original main bearings are referenced 63/28-3 so does the "3" on the end mean they are C3?

So, do we need C3 bearings or not? If we do, is it all the gearbox bearings or just some of them? Anyone know please?

62-22-9C3 bearing.jpg

Brian

ADDITIONAL INFORMATION:

After doing some more research, I found much better prices for the well known brand of SKF bearings from BearingsRUs. They didn't stock an SKF 62/22 but had a Koyo one available so I included that:

Number      inc VAT
2SKF 6302 Open Deep Groove Ball Bearing 15x42x13mm  £6.60
1SKF 6205 Open Deep Groove Ball Bearing 25x52x15mm  £3.88
1SKF 62032RS Rubber Sealed Deep Groove Ball Bearing 17x40x12mm £3.68
1KOYO 62/22-KOY Open Deep Groove Ball Bearing 22x50x14mm  £7.80
1SKF 60032RS Rubber Sealed Deep Groove Ball Bearing 17x35x10mm £3.60
      Total£25.56

 

 



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I have just got back from dropping the cases and barrel off to Dave Massam for boring. He said definitely use C3 on main and camshaft bearings. He uses C3 bearings in all his engine builds but standard ones in gearboxes. Of course, on the TTR the engine and gearbox share their oil so not sure that helped! He says the C3 only gives microns more clearance.

Dave is an old school motorcycle engine and refuses to touch anything Chinese, preferring old Brit bikes - the older the better. Fortunately, he is happy to do work for me on TTRs such as rebores. However, I don't think my case boring is going to be quick and simple as he wants to true everything up perfectly before boring so I need to visit again taking my engine stand and a pair of old main bearings. He is going to put a shaft through the old bearings to get things perpendicular and use the stand to level the cases up. I was also asked what "fit" I wanted for the barrel in the cases, a drop down fit, a snug fit, or a tight fit that might mean using some "persuasion" biggrin 

I don't think mine is going to be the £30 job that Steve, Simon and Dan had done no

Brian

PS The good news is that the All Balls main bearing kit that Steve sells here includes two Koyo C3 bearings - and its cheaper - result! biggrinbiggrin

All Balls main bearing.jpg

PPS C3 explained!

C3 explained.JPG



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Checked my local bearing guy.  Said straight up c3 for the crank/engine  gearbox OK with standard 

Best bet if the original is c3 replace with c3

 

He said some older bike engines run a c4  due to clearances changing with temp 

 

 



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Thanks Les. That agrees with my guy's opinion - C3 bearings for engine and standard bearings OK for gearbox wink

That means for the TTR, only the main bearings need to be C3 (as supplied in the All Balls kit).

With regard to non-OEM bearings, I think we have had a discussion about different makes of bearings before but it would be good to update.

I have priced KOYO bearings from Simply Bearings in my chart in my earlier post but am aware that there are many other options available such as SKF, FAG, NSK, etc. The same non-Koyo bearings can be obtained from elsewhere, such as Bearingsrus.co.uk, for half the price - about £40, which is a lot of difference! 

Anyone have any thoughts on that? I haven't placed my order yet wink 

PS My mate who had a Huskagiva-DT said his C4 bearings were horrendously expensive! Good that we don't have any of those in our TTRs biggrin



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I picked up my crankcases earlier today from Dave Massam after they have been bored to take the 350 barrel/sleeve.

He took great care to make sure that the bore was perpendicular to the centre line of the crankshaft. He did this by re-fitting the old pair of main bearings and turning down some rod to fit through them from which he could set up his his boring bar. It means that anyone else needing this done can take advantage of this as the bar is now ready to be used again biggrin

He also wasn't happy with the finish on Mr Yamaha's casings as there was a lip where the cases join. This is common on TTRs as the cases seem to be machined where the barrel sits without being bolted together. The base gasket takes this up but my guy wasn't happy with that so faced them off giving the base gasket the best possible chance of sealing wink

I was charged £60 because Dave had to make up the bar which took a bit of time.

Also, I think it took him longer to set the cases up as it was the first time doing it on a TTR.

He said any further case borings would be cheaper now he had the bar made and knew the best way to set the cases up wink

Dave is Rolls Royce trained and is a master of his craft. He pretty much chooses what work he does and he is never short of it with a row of engines there waiting on his attentions. I was happy with the charge and honestly thought it would be a lot more.  £60 because he had to make up the bar which took a bit of time.

Also, I think it took him longer to set the cases up as it was the first time doing it on a TTR.

He said any further case borings would be cheaper now he had the bar made and knew the best way to set the cases up wink

Dave is Rolls Royce trained and is a master of his craft. He pretty much chooses what work he does and he is never short of it with a row of engines there waiting on his attentions. I was happy with the charge and honestly thought it would be a lot more. He was working on an Ariel Square Four engine today

The crankcases will have to be thoroughly cleaned to clear any remaining swarf from the boring.

I have all the new bearings for inside, a rebuilt crankshaft (with new big-end bearing and conrod) and a new sprag ready to fit. I now need to take the guts out of a spare engine to get the gearbox parts etc wink

Progress!

 

Crankcases bored out.jpg



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Sounds complicated! Should have cost a bit more I suspect, but he sounds like the sort of guy who wouldn't be able to do a half assed job if his life depended on it, so he's not penalising you for his OCD
Got Tiddler's cases back today too. The race is on...

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You won't have any competition sadly Simon. I have done something to my back and it's agony to do anything much - just moped around the house feeling sorry for myself - and exceedingly grumpy cry

Hoping tomorrow will be better!

PS Just to put the record straight for other potential 350ers, how much did Tiddler's cases cost to be bored?



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Looking good Brian nice job on them cases keep the build stuff coming

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Ouch

hope your back gets better soon.

My cases cost £40, but done in the darkest depths of North Devon, nothing like your man Bri, sounds like he knows his stuff  and charges accordingly.



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Forty quid at Nametab Engineering in Redditch

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I have made a small amount of progress today until my back told me to give up cry

I have cleaned the remaining swarf out of cases and removed the main bearings that had been re-fitted to assist the boring process.

I also dug out the cylinder head that I had put back for the project many moons ago and stripped it down. Cams and journals look fine but I need to clean up the valves and valve seats before I know if they need anything more than lapping in.

I try to be methodical and like to put valves, springs and cam buckets back in their original homes hence the use of my little foam cutout tray on the right of the photo below. The green milk bottle top holds the collets.

For anyone new to stripping down a head, it is likely that you will only be able to remove the two cylinder head bolts that are on the RH (inside) of the head. The LH (outside) washers tend to stick stubbornly in place - and I usually let them stay there!

Checking and rebuilding the head can be a tad time consuming but its where the important work of the engine is done so it's worth taking your time. And I quite enjoy the job wink

I wouldn't normally bother but I think for the 350 I may make sure the inlet stub blends into the head and the ridge on the exhaust port is ground out. My slight concern is that, talking to my engineer who has decades of experience (in mostly Brit bikes it has to be said), he recalls Gold Star owners doing the inlet blending and mucking up the carburation as the step was built in by the BSA factory to encourage turbulence and a better fuel/air mixture! confuse

Cylinder head stripdown.jpg



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I suspect that was BSA's excuse for not having designed the inlet tract properly in the first place. Times have changed! I would definitely match the ports to the stub and header, but wouldn't do any polishing unless you're going to do a bit of gas flowing.

"Drop down" or easy sliding fit is fine for the barrel/cases fit. It's just a hole after all, and the dowels locate it. Never noticed the step in the base gasket surface before, but Tiddler's engine has it too.

I have to admit I don't understand all the bearing and centralizing bar malarkey. The base gasket surface should be a good enough datum - if not, Yamaha made a huge ****up (bigger than BSA's!!), and as I say, it's just a hole. Bolt the cases to the tilt bed of the mill, level it up using the base gasket surface as a datum, centralize the hole, and mill away. The head bolt dowels are what line everything up, not the sleeve. Still, I'm glad it's back on your bench.

Hope the back improves soon,

Simon

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There is a saying that "The first step is always the hardest" and I reckon that's very true.

So I pulled out the TTR this morning and started to strip out the engine ready to fit the 350 (when I have built itdisbelief) - so that's the hardest part done eh? biggrinbiggrin

Very muggy here in SW UK this morning so am not rushing. The existing 325cc engine has a new home lined up for it which is good!

Whilst the TTR is immobile, I will take the opportunity to drain the tank and let it breathe for a while before fitting new decals. Note to self - check you still have some decals to fit!

The powder coated frame is as good as when it was done and I would certainly recommend it as a finish if anyone is doing a frame up resto.

I am sure there will be lots of other little jobs to do as the strip down and rebuild progresses wink

Engine out1.jpeg



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Many years ago (if not more!), TTR Steve and I removed and replaced his TTR engine and got the bike running in just over an hour.

Today it took me from about 10am (with a break for lunch) until now just to get an engine out evileye

I am definitely slowing down disbelief

Now the slightly easier, but still time consuming, job of cleaning the bike and the engine unit up smile

Engine out 2.jpg



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Glad you're getting your mojo back Brian! You're right about starting being the hardest - it's breaking the inertia and getting going, and it's purely psychological. You have to be in the right mood for an engine rebuild as well, but the physical work doesn't take much time, especially with your experience.

An engine on the floor is good incentive. Looking forward to more soon,

Simon.

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If you need/ want a hand, I am happy to come help/ take the peebiggrinbiggrin



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