Hey,

a mate's sherco doesn't run verry nice any more (it used to do) it stil has a lot of power and revs high but on half trothle it sputters a bit, also when revving it it doenst sounds as sweet as it should. At full tilt it seems ok. The bike is fitted with an keihin carb done by the importer in the Netherlands. The bike is used weekly on an intermediate level, air filter is cleaned every time. fuel oil mix is ok, new sparkplug does'nt help. I wonder if it could be the exhaust (first part of the exhaust is cleaned regulary) or mayby the seals on the crankshaft. Any other sugestions?

regards bob

sorry for the spelling mistakes i am not used to write in English

Hey,

a mate's sherco doesn't run verry nice any more (it used to do) it stil has a lot of power and revs high but on half trothle it sputters a bit, also when revving it it doenst sounds as sweet as it should. At full tilt it seems ok. The bike is fitted with an keihin carb done by the importer in the Netherlands. The bike is used weekly on an intermediate level, air filter is cleaned every time. fuel oil mix is ok, new sparkplug does'nt help. I wonder if it could be the exhaust (first part of the exhaust is cleaned regulary) or mayby the seals on the crankshaft. Any other sugestions?

regards bob

sorry for the spelling mistakes i am not used to write in English

Hi

What mix ratio are you running on, and what two stroke oil are you using?

Hi

What mix ratio are you running on, and what two stroke oil are you using?

Put the dellorto back on and start from there. 33 pilot 118 main you're away.

Hi

What mix ratio are you running on, and what two stroke oil are you using?

i have no idea its not my bike (i drive 4 stroke machine) but i thought GRO 2 stroke oil

Put the dellorto back on and start from there. 33 pilot 118 main you're away.

But it used to run fine on the keihin, the bike has never been used with a dellorto carb. (it is a common mod here they even charge more for a new bike fitted whit a keihin, they do it on gas gas bikes also) It looks to me that it's a problem thats starts at a certain moment and gets worse by time, the bike is used a lot mayby even the piston that's used. Has someone already changed the exhaust on his bike for a new one? Does it make a big diference?

regards bob

Edited November 21, 200718 yr by bobtlr

But it used to run fine on the keihin, the bike has never been used with a dellorto carb. (it is a common mod here they even charge more for a new bike fitted whit a keihin, they do it on gas gas bikes also) It looks to me that it's a problem thats starts at a certain moment and gets worse by time, the bike is used a lot mayby even the piston that's used. Has someone already changed the exhaust on his bike for a new one? Does it make a big diference?

regards bob

Go onto the Sherco websites and you can download the manuals.........and tech info.........nothing to loose........but i use the oil they recommend.

Its very good and the bike cleans out well

My 290-05 had/has?(I'm still rebuilding it) a similar problem,the low revs/idle performance was erratic,it didn't splutter like yours but I know it could run a lot better low down.

I'm presuming that you wash out and clean your carb' and filter as a routine.

Here's a list of work(in order of complexity and cost )that I have carried out whilst fault chasing:-

1)Took off the carb' spacer plate.....very little difference.-Cost

Edited November 22, 200718 yr by HAM2

My 290-05 had/has?(I'm still rebuilding it) a similar problem,the low revs/idle performance was erratic,it didn't splutter like yours but I know it could run a lot better low down.

I'm presuming that you wash out and clean your carb' and filter as a routine.

Here's a list of work(in order of complexity and cost )that I have carried out whilst fault chasing:-

1)Took off the carb' spacer plate.....very little difference.-Cost

Has the engine been taken apart before this fault started??

Has the engine been taken apart before this fault started??

dabomb, if you mean my bike then ..no..I remember the previous owner denying any motor problems( I have no need to doubt the lad)and judging by the corrosion on the bolt threads I think they were last put in--bone dry-- Sherco factory style!.

Ok?

dabomb, if you mean my bike then ..no..I remember the previous owner denying any motor problems( I have no need to doubt the lad)and judging by the corrosion on the bolt threads I think they were last put in--bone dry-- Sherco factory style!.

Ok?

Sorry ham 2,i was replying to the fist post(bobtlr).The reason i ask,is because i had a similar problem my self regarding the spluttering etc.The previous owner of my bike(sherco 290) had replaced the piston,but putit in the wrong way round(believe it or not),took a mechanic to find it because the the guy i bought it off said he had never touched the engine,so i never looked for that sort of problem.

If you read this bobtlr,best way to check is remove the front pipe then crank the engine over,make sure the bottom of the piston doesnt come above the bottom edge of the port.

Sorry ham 2,i was replying to the fist post(bobtlr).The reason i ask,is because i had a similar problem my self regarding the spluttering etc.The previous owner of my bike(sherco 290) had replaced the piston,but putit in the wrong way round(believe it or not),took a mechanic to find it because the the guy i bought it off said he had never touched the engine,so i never looked for that sort of problem.

If you read this bobtlr,best way to check is remove the front pipe then crank the engine over,make sure the bottom of the piston doesnt come above the bottom edge of the port.

Hey,

as far as i know the engine as'nt been open yet, but i will check it the way you describe. The bike ran well in the beginning but now its not that good anymore, so i think mayby some component that's worn out? bike is now 2,5 years old and is used intensive. what should i look for first? piston, carb exhaust,...

regards bob

thanks for all the tips

Thanks for the tips,

the owner of the bike is a mate so i am not sure what he did on it but he takes good care of the bike, filter gets cleaned out in time oil changes etc. i'll give him your tips so he can try them . let me know if your bike improves with the new bearings and seals please.

regards bob

Newsflash 18.50hrs..just tried my new bearings and seals in the street.......and....... success...bottom end torque restored,idle much more consistent..

This is the only remedy that has shown any positive results for my particular bike...Good luck

hey thanks for the confirmation, i will pass all the tips to my mate

regards bob

The exhaust can make a difference.

We are fortunate in that I have other bikes to swap around suspect peices on too see where the problem lies.

If say you took your exhaust and swapped it with your freind, and then his bike ran bad, and yours ran fine, you would be fairly certain you had the problem.

This kind of thing, I usually try and start at the basics, and slowly proceede forward.

Clean new fuel, clean air filter, clean carb, careful inspection for air leaks, new spark plug, etc. etc...

Then look for the freind with the same bike and start stealing parts

Good luck, hope you guys find it and fix it.