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

yamahaTT250R · Veteran Member

question about installing camshaft properly

barra8 · Guru

By the looks of it you might have a streched cam chain or worn cam chain components as it does'nt look like it's that much of a difference to warrant a tooth out of position

Also could be the rotor itself but not likely

It would be good to see how close it is on the cam chain sprocket marks though.

Jarrah.

-- Edited by barra8 on Saturday 25th of August 2012 04:09:11 AM

barra8 · Guru

That will help and a few pictures of camshaft sprocket wear close up if possible

Diagnostic test and advice

When it runs you should not hear any noise in the top end apart from the usuall whirr the only noise should be the exhuast.

If you notice a slight rattling noise or excessive noise put the handle of a long screwdriver to your ear and the other end of the screwdriver to where you think the noise is coming from.

If there is any noise coming from the head it means a replacement cam chain will be needed

If the cam chain has'nt been replaced in awhile i suggest you replace it and any other cam chain components that have excessive wear

Not properly maintaining the cam chain and components will lead to serious trouble eg. bent valves,damaged piston and worse

The cam chain,cam chain components and everything needed can be bought for around AU $200.00 - AU $300.00 (depending of what needs to be replaced) at this site www.powersportsplus.com

Jarrah.

-- Edited by barra8 on Saturday 25th of August 2012 05:33:02 AM

yamahaTT250R · Veteran Member

i have looked at the camshaft sprockets, chain before i replaced the cover and they seem to be in a good condition...

as for any noises i am not sure if its normal but i am hearing a noise coming from the head but i was told that it was normal, ill try and post a video of it somewhere.

As for repacing the cam chain do i have to strip the motor to reach the crankcase cause that will be something i do not want to do.

-- Edited by yamahaTT250R on Saturday 25th of August 2012 05:17:06 AM

barra8 · Guru

As for repacing the cam chain do i have to strip the motor to reach the crankcase cause that will be something i do not want to do.

Jammed camchain.jpg

Yes you will have to take the clutch casing off and remove the drive gear sprocket to fit the new cam chain (see above)''

Note: In the above picture the cam chain is wrapped around the crankshaft and may be caught. Try not to do this.

Have heard of cam chain links but not for TTR250's

Tips on the job

Before removing the head, crack (loosen the nut) on the drive gear shown in picture above so it makes the job easier.

The back wheel if firmly on the ground (get someone to sit on it if you have trouble) will stop the motor from turning so there will be no need for ''special tools'' except a torque wrench

When removing the cylinder head make sure you undo the retainer bolts (these are'nt the head bolts) first as you will break the cam chain guide otherwize

Cut off an allen key and fit it to an electric drill (in reverse) or fit the cut off allen key to a socket and breaker bar or ratchet to remove any old/rusty/tight bolts so as not to strip the allen key bolt head

Make sure the cam chain does not wrap around the crankshaft as seen in the picture above or it may damage the crankshaft

Don't worry it's easy enough and if you need a manual let me know and i will send you a pdf. full workshop manual to your email address

Jarrah.

-- Edited by barra8 on Saturday 25th of August 2012 07:04:04 AM

yamahaTT250R · Veteran Member

ok thats good i thought i had to remove the entire crankcase section including the gearbox
anyway heres a video of it : http://www.youtube.com/watch?v=w7fKI4fFQQw&feature=youtu.be

barra8 · Guru

Watched the vid and that is almost certainately cam chain rattle

Fitting a new cam chain asap will be crutial to ensure that no further damage is done to the engine.

Sounds like it may have even been loose enough to be wearing inside the barrel in the cam chain chamber but should'nt matter if it's not too badly worn.

I'd replace all components with excessive wear aswell as the cam chain before riding anymore but up to you

Jarrah.

-- Edited by barra8 on Saturday 25th of August 2012 06:38:09 AM

TTRfan · Super Guru

A simple visual check that can be done is to remove the tank and cam cover and put the engine to TDC.

The timing marks on the cam sprocket should be almost exactly in line as in the pic below:

Worn timing chain marked.jpg

If they are not in line, for example they are in the position of the blue lines on the LH sprocket, then this usually indicates a worn cam chain.

The chain isn't expensive to buy but time consuming to replace as so much has to be stripped out to fit it.

Brian

-- Edited by TTRfan on Sunday 5th of May 2013 09:00:29 AM

yamahaTT250R · Veteran Member

it seems to be ok to me anyway here are some pictures and ive checked for any damage to the barrel and have found nil :) very happy

tell me what you think of the pictures good or not?

could worn camshafts make that noise by any chance?

Also on my TTR it does not have this so called stopper guide.... i was wondering if this part is only on USA model TTRS? see pic 4 and 5 outlined in red.

yamahaTT250R · Veteran Member

hmmm maybe ill try taking some pictures inside later as im busy now thanks for the input.

barra8 · Guru

Put a screwdriver to your ear to check where the noise is coming from while idling the bike as mentioned in my last post.

Sounds to me like you have a worn cam chain and or components.

It is hard to tell if your chain is worn

If in doubt i would buy a new cam chain and components

Would like to hear the noise also but i'm pretty sure it is cam chain rattle if your rings are good (ie. no smoke,compression right)

Jarrah.

yamahaTT250R · Veteran Member

ill take some photos of my camchain + cam shafts tonight hopefully and get back to you.

barra8 · Guru

Okay but may not help if i can't see the wear.

With the cam timing mark out of spec and the noise i am 99.9% sure that it is your cam chain though.

Jarrah.

barra8 · Guru

Bummer about the cam chain but it must be replaced asap

there is a hole but it does not have any thread in it nor is there a stopper so im assuming there is none in my model?

It must not be installed in your model athough if you want you can tap thread and fit it.

Jarrah.

-- Edited by barra8 on Saturday 25th of August 2012 02:14:06 PM

barra8 · Guru

Thanks Brian,

I was trying to find that pic to show him but could'nt.

I think that confirms my thoery of a worn cam chain 100% now.

Jarrah.

barra8 · Guru

First question:

Here is a pic of what will happen if the camshaft chain is not maintained properly. This is'nt too bad and could be used again. (see below)

They usually drop a valve before too much damage has occured so not a real concern...

Note: You will not be able to see this wear until the head or atleast camshafts are removed.

Second question

The pictures are okay and confirm that you have a worn cam chain 100%

Third question

Check for wear on your camshafts but i highly doubt the noise would be caused from camshaft wear

Fourth question

Have a look on your head cover and if there is a bolt hole in your head cover and if there is the part you point out with the red arrow should be installed.

The part you show with the red arrow is not something the chain sits against. It is just in case the cam chain hits the top of the head cover (like a stopper)

Jarrah.

yamahaTT250R · Veteran Member

there is a hole but it does not have any thread in it nor is there a stopper so im assuming there is none in my model?

barra8 · Guru

You would be better off taking the head off it. An easy job and gaskets cost just about nothing.

Also you can check the rings and whatnot while you have the head and barrel off.

I'm pretty sure you would be able run wire down the head then attach it to the timing chain and retreive the chain.

I'm not 100% on this because i have always done the job properly from the start to finish.

Checking the wear on the cam chain guides would become more of a job than it saves.

Also checking if valves are seated properly would not be possible without removing the head.

You could check the valves by using a compression gauge but it won't do as good of a job as checking with the solvent in ports to see if they leak method.

It would be up to you which way you go about it so take your choice wizely.

I know what i would be doing though and thats removing the head.

Jarrah.

-- Edited by barra8 on Sunday 26th of August 2012 08:25:32 AM

yamahaTT250R · Veteran Member

i got a question about fitting a new cam chain does the whole head have to come off or can i somehow do it without taking off the head?

barra8 · Guru

That's okay and if you could please let me know about powersports service and postage ect. so i can use it for feedback for my thread eg. http://ttr250.activeboard.com/t50448087/usefull-internet-links-info-for-restorations-and-maintenence/ that would be great

ok thanks for the input, today i ordered the parts from powersports hopefully it will fix this noise.

As mentioned the noise will be timing chain rattle from the chain being loose and ''slapping'' up against the barrel see pic below..

All will be good when you install the new cam chain & (components if worn)

Jarrah.

-- Edited by barra8 on Tuesday 28th of August 2012 06:10:04 AM

yamahaTT250R · Veteran Member

ok thanks for the input, today i ordered the parts from powersports hopefully it will fix this noise.

thanks again for the help ill get back to you when ive completed the task hopefully with good results.

TTpower · Veteran Member

G'day lads,

How many miles/kms should we be getting out of a cam chain?

I'm in the middle of doing mine as well its great timing.

Thanks for the PDF to barra.

barra8 · Guru

TTRfan wrote:
yamahaTT250R wrote:
alright i will give the details once they arrive, also i wanted to ask do i have to remove the entire clutch basket inorder to access the camchain?
Yes.

Not to be a pr#ck Brian but the only reason why you would have to remove the ''entire clutch basket'' is if you had to replace the cam chain guide which is behind the 'clutch basket''

You can just remove the nut in the pic below as mentioned and oil pump.

barra8 wrote

Tips on the job

Before removing the head, crack (loosen the nut) on the drive gear shown in picture above so it makes the job easier.

The back wheel if firmly on the ground (get someone to sit on it if you have trouble) will stop the motor from turning so there will be no need for ''special tools'' except a torque wrench

When removing the cylinder head make sure you undo the retainer bolts (these are'nt the head bolts) first as you will break the cam chain guide otherwize

Cut off an allen key and fit it to an electric drill (in reverse) or fit the cut off allen key to a socket and breaker bar or ratchet to remove any old/rusty/tight bolts so as not to strip the allen key bolt head

Make sure the cam chain does not wrap around the crankshaft as seen in the picture above or it may damage the crankshaft

Good opportunity to clean the oil pump also.

Jammed camchain.jpg

Jarrah.

-- Edited by barra8 on Wednesday 29th of August 2012 03:13:52 PM

-- Edited by barra8 on Wednesday 29th of August 2012 03:17:36 PM

barra8 · Guru

barra8 wrote:
TTRfan wrote:
yamahaTT250R wrote:
alright i will give the details once they arrive, also i wanted to ask do i have to remove the entire clutch basket inorder to access the camchain?
Yes.

Not to be a pr#ck Brian but the only reason why you would have to remove the ''entire clutch basket'' is if you had to replace the cam chain guide which is behind the 'clutch basket''
You can just remove the nut in the pic below as mentioned and oil pump.

barra8 wrote
Brian is right about the chain guard not letting you take the cam chain although.......

I have decided that it is possible but not practical. The bolt under the basket won't remove but it does loosen enough to slip the chain past.

I'd be removing the basket as it's so much of a hassle if you have the kickstarter fitted cry

I have replaced many cam chains before without removing the clutch basket but in this case ''it is possible but not practical''

Jarrah.

Maybe it would just be easier to remove the basket with something like this biggrin

-- Edited by barra8 on Wednesday 26th of September 2012 02:14:08 AM

barra8 · Guru

I found this out by actually taking the oil pump,drive gear and undoing the back bolt. Once you loosen the back bolt the cam chain guide pivots down which allows plenty of room to install the chain. It really was'nt that hard apart from finding the right length 10mm spanner to ''crack'' loosen the back cam chain bolt.

The front cam chain bolt can be done with a torque wrench

The back cam chain would have to suffice with a normal tightening procedure. This would not matter aslong as you tighten it back up enough as its not a moving component.

The reason i only just found this out was because earlier i had only measured the distance in ralation to the cam chain guide/clutch basket/crankshaft/

but not actually tried doing it.

I knew there was some ''trick'' to it but couldn't remember the ''trick'' (If that makes sense) I thought the trick was taking the oil pump off and drive gear nut but obviously ''aint''

I have done this to other bikes but never had to replace a timing chain on a ttr250 but that day will be very soon when my 05 model head arrives in the post. But that's another story or ''novel'' i should say

This method does work though.

All this ''said'' though i would just make up a tool like i did it was basic and makes alot of jobs easier for me. Also cost me nothing so no complaints there.

Jarrah.

-- Edited by barra8 on Thursday 30th of August 2012 06:36:49 AM

yamahaTT250R · Veteran Member

alright i will give the details once they arrive, also i wanted to ask do i have to remove the entire clutch basket inorder to access the camchain?

yamahaTT250R · Veteran Member

hey mate its been approximately 20000km on mine so i wouldnt be sure when to change yours.

TTRfan · Super Guru

yamahaTT250R wrote:
alright i will give the details once they arrive, also i wanted to ask do i have to remove the entire clutch basket inorder to access the camchain?

Yes.

barra8 · Guru

Old timing chain is all i can think of. Have had a good think too.

Maybe it gets stiff when left for awhile and when you started it it only sounded better when cold?

Either way you will have to replace the chain.

It can't be anything else other than valves need re-shimming.

Unless it blows smoke???? confuse

...........................................................................................................................................................................................................................

Jarrah.

-- Edited by barra8 on Monday 3rd of September 2012 09:38:16 AM

yamahaTT250R · Veteran Member

hello again while waiting for the parts to arrive i decided to start the bike today just a little cause i havent started in in over 4 days and i kept it on, now what i want to say is the noise has dissapeared....whats going on guys anybody know? im still going to change the camchain and other worn parts but can anyone give me ideas?

barra8 · Guru

yamahaTT250R wrote:
hey mate its been approximately 20000km on mine so i wouldnt be sure when to change yours.

Not sure whether you meant 20,000km

Or 200,000km ?? confuse

.......................................................

You must mean 200,000km ?? confuse

....................................................................

see this thread Quick guide to Repairs&Maintenance/Questions&Problems&Solutions

Jarrah.

-- Edited by barra8 on Monday 3rd of September 2012 01:04:02 PM

yamahaTT250R · Veteran Member

no actually i ran it till it was hot and it didnt change also no the motor is in great condition there is no smoke.

yamahaTT250R · Veteran Member

no i meant 20000kms as in my engine mileage has been 20000kms and the cam chain hasnt been changed since then i was trying to help TTpowers question which was:
G'day lads,

How many miles/kms should we be getting out of a cam chain?

I'm in the middle of doing mine as well its great timing.

Thanks for the PDF to barra.

barra8 · Guru

Okay well hope your parts arrive soon,

Let us know when they do.

.....................................................................................................................................................

Jarrah.

barra8 · Guru

Just remember to make it easier on yourself & undo the clutch boss nut before removing the head.

Or if doing it the cheats way remove the drive gear nut (pic below)

Jammed camchain.jpg

Jarrah.

-- Edited by barra8 on Wednesday 26th of September 2012 02:10:50 AM

yamahaTT250R · Veteran Member

Ok finally the parts have arrived today...nearly 1 month..