Return to Idle

[DRW14]

Hi - I'm new to Go Karts and I'm doing a project with my lad on an old Manco Dingo 285 fitted with a B&S engine. The Kart has no control and takes off by itself - the problem is around the throttle / linkage etc - the butterfly on the carb just will not turn back to idle - getting WOT is no problem and the vibration of the engine does that by itself. Ive tried changing the main spring on photo but no effect, i cant easily reach the govener spring but can see it looks ok but difficult to say. Ive tried putting springs on the carb butterfly in various places but minimal tension prevents the throttle opening or just keeps it open. Ive adjusted the tension in the pedal cable. cleaned and greased everything i can. is there any pictures of the same set up to see whats wrong? or suggestions? thanks.

 

[Budget GoKart]

I have the exact same setup if your go kart has a govenor the fix wont work because you wont have throttle but i suggest getting a very thin weak spring and attach it to the butterfly to the shrough by the sparkplug on the head ill get a pic of my setup

 

[itsid]

the original springs age,
rust, temperature changes (hot engine cold envronment over and over again)
over time they weaken and need to be replaced every decade or so.

But a seperate return spring on the butterfly is a good idea to solve that.
first use some light machine oil on the butterfly pivot shaft,
and add a small return spring to the lever.
it'll snap back nice and sharp I bet

'sid

 

[DRW14]

Thanks - a picture and any ideas for a weak spring would be great

 

[itsid]

I wouldn't put too much emphasis on the "weak" part tbh.
a nice spring for that task would be the governor lever return spring for example
(part # 262310) but tbh it's not too different from the original butterfly return spring anyways
so I think you get the best result with that instead (part # 26262288)
if I'm not mistaking the butterfly return spring is indeed a bit weaker,
but mine might just have been swapped *shrugs*

Also make sure to clean and oil the pivot of that bell crank so the spring has afighting chance to move the butterfly at all

'sid

PS oh btw.. a sticky throttle cable will always prevent the original well working butterfly return,
so add TWO throttle return springs at all times to any engine (one on the lever/pedal/twist throttle and one more directly to the linkage you connect the throttle cable to on the engine itself)

 

[NightHawkJ30]

Check throttle cable make sure its not to tight.