Idling issues

[Kephasd]

Hi all,
I have an O.S. .18 cv-r. I cannot get a low , consistent, reliable idle. I have no problem with top end tuning. If I close the idle screw it will drop down slightly but its erratic. It will eventually stall out (not because I am trying to win a longest idle competition it stalls depending on how I apply throttle before braking usually. I am also tuning the low end needle. I also never sealed the engine when I bought it. Would an air leak cause an erratic idle? If I need to seal it do I need to take apart the whole engine and clean it? Or can I simply remove the backplate, carb ect. And clean where I am going to seal them?

Thanks for all the help.

 

[bgbdwlf2500]

Hi all,
I have an O.S. .18 cv-r. I cannot get a low , consistent, reliable idle. I have no problem with top end tuning. If I close the idle screw it will drop down slightly but its erratic. It will eventually stall out (not because I am trying to win a longest idle competition it stalls depending on how I apply throttle before braking usually. I am also tuning the low end needle. I also never sealed the engine when I bought it. Would an air leak cause an erratic idle? If I need to seal it do I need to take apart the whole engine and clean it? Or can I simply remove the backplate, carb ect. And clean where I am going to seal them?

Thanks for all the help.

id start with a sealing issue meaning seal it. look for the vids on youtube to do it. its not hard to do. cleaning never hurts anything

 

[olds97_lss]

HEre's a walk through:
https://www.rcnitrotalk.com/forum/showthread.php?t=72487&highlight=shim

Are you sure you have things adjusted properly? You may want to check out your tune. A lot of guys run too rich on the LSN, which causes issues with idling and the idle screw not adjusting much.

Or, you may have your clutch dragging so when it does get down in RPM, it stalls out.

 

[MotoGod]

Another thing to consider is as the engine wears out you will have to steadily increase the idle to keep it running properly. If you try to set the idle too low, it will just be erratic and stall out on you. I would take it apart and check out the piston/sleeve fit while you are sealing it. If the piston moves up past the "sweet spot" markings on the inside of the sleeve...you may want to consider a pinch.

 

[Kephasd]

So I sealed the engine last night and took it out for a spin. And Wow having a sealed engine vs. Non-sealed is like night and day she held an idle perfectly. I am going to seal all of my powerplants from now on.

Thanks all,

 

[MotoGod]

Yeah air leaks wreak havoc on these little engines for sure. Newer engines tend to seal better with their O-Rings and such,,,,but a little sealer goes a LOOOONG way. hehe