Guy's am new to the forum, just bought my son a 2001 Sherco 290. Compared to my road bike the throttle return seems weak to say the least, should the throttle have some kind of return spring on the carb ? If so what is the best way to get in and check/replace ?

Thanks in advance - Mick

Yes, the spring would be in the top of the carb, where the throttle cable attach to the slide of the carb. There is 2 bolts to undo on the top of the carb, I think a 8mm socket will do it. This will free the slide/spring/needle assembly. Check the state of the spring. Never seen a broken spring there but you never know, or maybe previous owner fitter an non-original spring? You can also pop off the plastic cap of the Domino twisting grip, so you can see if some debris or damage is causing the wheel/guide to slow down the return of the cable. Lastly, see if the the wire inside the cable housing is moving freely. An old rusty cable could also be the culprit here ? And what about cable routing: no interference/bad kinks, etc. ?

Edited February 17, 201214 yr by hugo

Thanks hugo, I will try out your suggestions.

Check twist grip has not move up the bars allowing the grip to bind on the end of the bars if it has fallen over on that side

Hi Hugo,

Deffo check the cable routing as this is often the cause. New cable can sort it.

N

Slide back boot off throttle assy, pop off top cover of domino throttle assy to frmove cable from throttle. Manually operate cable for return pressure and smoothness. You should easliy be able to detect spring resistance and hear the carb slide hit home. (all without motor running of course)

Feel for drag in the throttle tube itself. May need a clean. Insure grip is not dragging, as stated..

I think I have the same issue as the OP, it's not that the throttle is sticking or hard to pull, it is too light and too easy to pull. Makes trying to ride it more difficult to control. Maybe Dellorto has higher rate springs for these carbs.

I think I have the same issue as the OP, it's not that the throttle is sticking or hard to pull, it is too light and too easy to pull. Makes trying to ride it more difficult to control. Maybe Dellorto has higher rate springs for these carbs.

No, the spring rate should be quite lite, yet still positive and fully slam the slide shut on its own if all correct. Without the motor running, allways ck to insure you hear the slide hit home with a solid ckick after working on the bike and before starting it..

If your cable throttle or grip is dragging, fix it! Needs to be perfect! Abit of lite oil on the throttle tube to bar interface is recco. Clean and re lube on occasion.