Atv would not sit idle withou the choke being on

changed the carb jets and full carb rebuild

now it wont sit in idol at all even with the choke on

iv had someone say its taking in too much air, but the problem i have is the idle screw is seized so ic ant adjust it. I will renew the idol screw but has anyone else got any advice on what it may be thats causing the problem

 

Well, there is the problem.

If you break the head off the pilot screw, you will have destroyed your carb. BTDT

If you are in danger of breaking the screw head, use some heat. I use a propane torch. Not too much!

 

the idle screw is weird its attached to a cable that sits on a small hook like bracket. that's has seized but im wondering if there is a way of replacing the whole cable maybe?
do you think that if that idle screw is stuck it will shut down completely when left idle? even if the choke is on fully?

 

That is the idle set screw.

Many quads will idle with the idle set screw fully out (throttle completely closed), getting all fuel and air thru cold-start passage and idle jet. Some, you need to have the idle open at least a bit. If you have other air leaks, probably not.

 

so you think if I sort idle screw set out and get that working that should do the trick ?

 

IMO, no.

You have air leak and/or idle circuit problems.

If you can not even turn the idle set screw, you likely have corrosion issues.

 

so what’s my next step?

 

Next step?

If you can get engine running at all, then do so, and spray carb cleaner all over the rubber intake manifold. If you hear an RPM change, that is from an air leak. You may also have a vacuum petcock on that Raptor, I can not remember. If so, it must be connected and not leaking anywhere. Spray all over the hose and petcock while engine is running. Get the engine running as slowly as possible, and hold it there.

If none of this helps, you prob missed something inside the carb. There are some mighty small holes inside there. Sometimes, an ultrasonic cleaner is needed. I have one, but it does not cure all.

 

update for you guys.

No clear leaks in the boot after check
no cracks in the manifold or visual issues
if i put a rag over the air intake it rides alot better and sounds great and sits idle
if i put the choke on it will sit idle but chugs and bogs a little
if i take the choke off it over revs like crazy almost like its back to front

I have checked all through the carb again and there is no fuel mixture screw on my carb. only an Idle screw, im not sure if someone took it out before I had it but there is not one there

I have had to purchase a new carburettor as i have now run out of options. there must be an air leak somewhere

Hope this forum helps others one day and thanks for all your input and advice
a new carb is all else it can be i have changed everything else haha

 

Post a photo or 2 of the bottom of your carb. The pilot screw may be missing (large air leak!) or capped over to hide it. I will see if I have any photos of a 350 Raptor carb.