I have now come round to the idea that my 250 sherco ( 01 vintage ) now needs the main bearings changed. My question is this , can the bearings be changed without splitting the engine or does it have to be 'split apart ' . I have asked my local dealer about a price to do the job and he says if I take the motor out of the frame and deliver it to him he will do for about

Gday, the engine needs to be split. If you are unsure of the job, pay someone to do it for you - much easier and less worry for you.

Cheers,

Stork

Agreed, you will have enough to to getting it out then back and running.

If he has the stuff, it is a quick turnround as well.

Just replaced them on my mates Gas Gas, cost for bearings and gaskets was over

Thanks very much for your imput . You have all probably endorsed what I was thinking myself , so it's out with the motor and off it goes ! Will probably change little end and piston rings at the same time .

Thanks Again

Phil

Probably a fair price for the benchwork labor, doubt that would include the parts as someone suggested.

By my adding that wouldn't include parts, costs below

Main bearings 18.29 x2

Crank seals 5.92 x2

Clutch gasket 4.85

Centre gasket 5.92

Reed gasket 1.13

Base gasket 5.69

Total 66.01

Then add

Piston rings 21.46 x2

Little end bearing 30.13

Grand total 139.06 GBP

Not an excessive price for a full engine rebuild after 8 years really, if you where talking mx change that to 6 months

I'm pretty much spending that on my Jarvis which has plenty of hours(be into 4-5 figures) & the piston & barrel are both still fine, engine rebuild is easy for me so no labour cost involved.

Edited August 22, 200917 yr by tony27

The motor's out and been delivered to the dealer . The price has now gone up to

Pretty cheap really, if the motor was quiet apart from the mains then your piston should be fine. I'm not sure whether the 01 still used the same piston supplier as the 99 which had a very heavy/solid piston compared to the 290s & later motors but if they did it will be good. Unfortunately if it does need doing my guess will be around 300 pounds all up for a motor that will give years more troublefree use

Got the engine back now , it didn't need little end or piston rings , apparently everything was alright except for the mains ( it was once described by a friend of mine as sounding lika a cement mixer ! ) . So it's now ' nailed ' together and just been started on the second kick , sounds like new . So i am going to take it out this weekend for a shakedown test just to make sure everything is right .

Would it be better to slightly increase the amount of two stroke oil for the first mix for a running in period or not ?

In theory everything will have been well oiled on assembly. Seeing as you only had main bearings done you should be able to get away with a short period of gentle work before using as was intended. Adding extra oil to your fuel has the effect of leaning out your mixture, even from new sherco doesn't recommend extra oiling

Thanks Tony,

What do you think , about an hour of easy work first before I go into Cabestany mode ( I wish ! ) or more ?

Phil

that sounds like a great deal to me.

I have to tear into my transmission to figure out where my 5th gear went.

Or I'll just let the shop do it. I hope I get such a good deal on that as well.

Go play in some slow speed technical stuff like tree roots where you don't need the big handfuls for a while & things will be fine, roller bearings actually don't need bedding in unlike pistons & rings.

Trials riding is really the best thing for running in a new motor because of the constant engine speed changes, just take it easy & make sure everything is working correctly