Just picked up my shiny 2001, 290 & thought I had better check it over, bottom line is I put a flat 6" bladed screw driver in the 6oc position between the flywheel & the casing and (gently) lifted it & I can detect movement and a gentle "clonk" I would expect a little bit of movement and the bike rode OK (Last bike I had with shot mains vibrated like a b@st@rd) so I am a little unsure if this is normal or I am heading for my first rebuild in many years.

All thoughs greatly appreciated.

Mike

Was afraid of that, thanks ..... looks like Iwill be riding the TY for a while longer !

Changing out the mains is an easy job, I just did it on an "02". I used the engine tear down manual from the Sherco and RYP sites. It provided some good information.

The only special tool that you really need is the flywheel puller.

Wayne

Thanks Wayne, oddly enough I have just been printing the manual out, but useful to know I only need the puller. Do Sherco do a gasket set or will I need to buy them separately ? if separately is it obviouse what I will need ?

Regards, Mike

Apart from riding the thing round the garden I have not been anywhere on it ! hard to believe I trained as an engineer

Hey, you know what, if the play is little, do not bother.

1999 before Scottish I hade a nearly new Bultaco(Sherco) (one trial)

I usualy check everything before SSDT, and much to my horror, suprice,

the play was there.

We check it on bright new Bultaco(Sherco) to compare and the play was on the bright Bultaco as well.

Explanation I got was, that in Spain is warmer and thats why... Hmm..

I did my Scottish, did more trials that year, sold the bike and the new ouner is still riding Bultaco, without changing bearings..

Well,

if it is not very noise and very BIG play,

don

There has to be some looseness in the main bearings or they would lock up. A couple of thousandths is normal, 3 or 4 may be the limit for service I would guess, .005 or more would be bad!

I am not sure what it tells me but I just measured the movement with a digital vernier and it tells me there is 4 1/2 thou movement at the fly wheel.

Also checked the air cleaner and oil last nite (dry and old) so suspect not the most loved of bikes.

The plan is to keep the bike so I am pretty sure its tear down time

btw Information and comment much appreciated, thanks

Addition- just made the same measurement on my TY and its about 2 1/2 thou

Edited July 31, 200521 yr by arun1664

Hey Honda RS

Just thought you would like to know that a bearing with a C3 clearance in it means that it has more clearance than that what a standard bearing has.

If you fit a normal bearing on the crankshaft the bearing would seize and lockup. With this in mind you can get movement in the main bearings.

Johnnysherco

Mike,

If you plan to keep the bike then I would suggest that you do the same thing that I did:

1. Take the engine out of the frame and split the cases.

2. Replace any suspicious bearings/seals (I replaced the main bearings/seals and the countershaft bearing/seal) - I should have also replaced the gear shifter shaft seal and the kick starter seal.

3. Check the piston/cylinder clearance - factory is around 1 - 1.5 thousands. Replace the piston if necessary, they are available in a,b,c and d sizes.

4. I also replaced the gear selector return spring, it can fail and you will not be able to shift gears.

5. Rough up the Clutch steel discs - Use a piece of glass and 400 grit wet and dry sandpaper.

I would also take the time and check the water pump shaft and seals, they may have been changed, if not this is a good time to replace them. The manual on the Sherco site shows exactly how to do it. The top end maintenance manual is also handy.

All of the necessary torques are spelled out in the top end maintenance guide and the lubrication and maintenance guide.

Installing the engine back in the frame was the hardest part of the job for me, it just took some time and effort, I used a big C-clamp to pull the bash plate back into position.

Good Luck,

Wayne

As reply to the c3 bearings, regarding to the movement felt when grabbing the flywheel/crank assembly.

When fitting a c3 bearing, a little freeplay can be felt when grabbing the flywheel. It is not!! a clocking noise as mentioned earlier in this topic. But it can be felt. Mine mx bike is fitted with c4 bearings, so with even more freeplay standard. And i can feel some axial and radial movement which is needed for good healthy operation of the crank.

It all comes to rpm's and heat. The more rpm's, more heat, the more expansion of the bearings, the more clearence needed.

I know above statement is a little opposite of the common heard knowledge but 0.05mm freeplay can be felt. And is not a bearing failure.

Above makes me wonder can trial bike work with standard c2 bearings, since they make little to none rpm's, so it wld only have to deal with heat.

Maybe someone can reply on this, outof experience.

Something to note!

The bearing will measure less clearance when it is in oil, as the oil provides a "cushion".

Wayne, do the bearings spec at "C2" or "C3"?

ps- always ck air filter for water after washing the bike as this is the most common reason for dirt ingestion and bearing wear in a Sherco. You will lucke if the throttle slide does not stick, wide open!

Help ! from down under NZ .what is the address for the downloads for the 290 manuals.?

Thanks.

04s have c3 from the factory

Help ! from down under NZ  .what is the address for the downloads for the 290 manuals.?

Thanks.

Click for Ryan Young's Web Page

OK so I have started taking the thing to bits and am looking for a tip on how to restrain the clutch basket so I can undo the nut on the primary drive gear.

As always, all help appreciated .... Mike