F-134 Won't Idle, revs fine

I've searched the posts...I've changed every electronic part (but the coil), compression is good, float isn't too high, timing is on time...added a ballast resistor, but my f134 still idles, skips, then dies...even charged the battery....what am I missing?? what should I check again????

 

Re: help!!

does it run with throttle opened?? Is it only a problem at idle??

JB

 

Re: help!!

water in the fuel? Filter clogged? fule pump working?

BUBBA

 

Re: F-134 Won't Run

It revs fine, problem is at idle. Engine runs rough, starts skipping and then dies. I'm going to look at the coil a little more today. Has anyone ever tried hotter plugs? I put in a set or ac r45. they are a little longer on the end..no change in the motor with either plugs. The only other thing I can think of is the little weight in the YF carb. The manuel shows a ball with a weight above it..both of my carbs and the kit have a weight with a cone on the end. The book says it should hold gas for 60 second...mine doesn't and I haven't been able to fix it. Would this possibly be the problem? Any suggestions on how to fix it? hammer and ball bearing haven't.

 

Does it idle for a few seconds OK, then start to run rough, starts skipping, and then die? The key here would be that it runs OK for a couple seconds first. If it does, it sounds like the carb is flooding. If it doesn't then I would think that the idle circuit is clogged. I don't think ignition is the issue here. Sounds like fuel to me. Try adjusting the idle mixture. If its too far in or out you can have the same problem. If you adjust it in and out and it makes no difference, take it all the way out while keeping it running and try some carb cleaner in the recess the adjustment screw just came out of.
Fuel problem......thats what I'd rule out first.

 

I agree, I belive the inital setting for mixture is to turn it all the way in and back it out one full turn, mine is another 1/4 turn after that your may be different.

 

What about an air leak? Sucking air at the carb/manifold gasket? Try spraying a little starter fluid around the area, if the revs jump up you're sucking air.

Just a thought.

 

No air leaks, I'm going to rebuild another YF and try that. Would it help to adjust the valves? I haven't done that yet.

 

Before you rebuild that YF, do a search here on the carb. Trust me on this one.

 

Lots of good suggestions here. I'll add one assuming you have the dwell set correctly on your points and the problem is really fuel related (????).

I had my fuel tank lined few months ago and the guy doing the job used some silicone sealant when he replaced the fuel sending unit. After a while, some of the silicone made its way into the tank and to the fuel pump and it to stopped running. I removed the tank and cleaned everthing from the tank to the carb.

However afterwards, I found the fuel mixture screw required frequent adjustments to keep the idle smooth. Sometimes it would do just like you mentioned, idle fine for few seconds, start getting rough and sometimes it would choke down.

I pulled the carb, cleaned the bowl, pigged evey line with piano wire & blew it all out with compressed air and now it works fine. I did find theres a difference in the optimum adjustment setting for smoothest idle between cold and hot. So I make the final adjustment at operating temp. It's a little "cold natured" for the first few minutes but once it warms up it creeps through the woods smoothly and quietly which is important during deer season which starts Saturday.

Eddy

 

Well, I rebuilt a different carb, put it on and had the same problem...but then it smoothed out...but wait...it was running out of gas...poured more in the tank and it started running rough again. I had found an old reciept in it's paper work with note on it saying that it needed an new fuel pump..is it possible my fuel pump is putting out too much pressure???

 

Too much pressure could cause it to flood at idle. Fuel bypassing the needle and seat valve. could be...