My friend's YS110 is having idle problems. The top end is fine but when you bring it to an idle, about 2,500 RPM, the engine will idle for like 8 secs then it will speed up and die. We tried to richen and lean up the low end to see where it leads, it still does the same. There is no fuel leaking from the carb, all looks good and its a new engine. Any ideas? Thanks!

Tried adjusting the regulator? Go to www.ysperformance.com and follow the running instructions.

The regulator can affect it? How? Thanks!

The regulator controls the transition. At 2500 rpm, you are into the regulator adjustment.

Go to www.ysperformance.com and follow ALL of the instructions.

Dave ... its dying after idling for about 8 secs and the RPM rises before it dies. I will double check the regulator. My YS110 never gave me any trouble ... maybe my pal is jinxed! Hehehe ... thanks!

I am having a problem, mine has quite alot of fuel dripping out the carby, and when i throttle up it is bogging down like it is way too rich on the bottom end. I have set it to 1 1/2 turns, does this sound normal? Should I lean the bottom end more?

If you haven't gone to www.ysperformance.com and followed the instructions, do it.

Make sure the regulator is clean before doing so.

The 110's had some issues with the regulator until about a year ago when YS changed to a different unit. If you have an earlier 110, it may need to be repaired. How long have you had the engine?

Dave ... thanks!

Only bought it last month, How can you tell if it is the old version or the new version. I probably needs some more running in, It is reliable so i'll just get some more fuel thru it. Unless you have any more suggestions!

Thanks for your help Dave.

Where did it come from? If it came to you from the US. It's almost guaranteed to be the newer version.

Check the valve clearance. It should be .003" on both valves.

Thanks for that Dave i will do that. Do you ever need to adjust the regulator?, I have been warned off touching it. don't know if the problem is there some where. I bought it from the Australian importer so i don't know but i suspect it is the newre version!

If you go to www.ysperformance.com you can see by clicking the instructions button that you will adjust the regulator. Anyone who tells you that the regulator should not be touched is an idiot. Why would they have put that big adjusting screw on it if it wasn't meant to be adjusted??

I have narrowed it down, The main problem is after it idles for a little while, when I go to power up it chokes at about quarter throttle like it has a gut full of fuel. Is this the low end or the mid range with the pressure regulator? Also what is the correct idle RPM the instructions on the link say 2200 to 2400 this seems high!

Adjust the regulator. 2200 to 2400 is correct. After the engine is fully broken in, you might get to 2000.

Dave:

I am having a similar problem with my 110. I previously had an air leak around the airbox but at your's and Richard's suggestion, I replaced the airbox gasket. The method of replacement as Richard suggested should allow the airbox to be tightened evenly without the airbox cover hitting the carb. Richard suggested that the pressure from the carb causes the airbox bolts to be tightened unevenly.

So, I loosened the head then tightened the airbox bolts with a tourque wrench (about 13-14lbs. lowest touque settiong on wrench) to be sure the bolts were evenly tightened then tightened the head assembly back down and the engine ran great for about 10-12 flights.

It seems that a new and perhaps unrelated air leak is occurring where fuel is leaking out of the carb and also air is leaking out of the carb. I tested this by disassembling the plane and removing the motor as I first suspected that there was a tank leak and I used an air pump and removed the lines from the engine and at this time I determined that there was no leak in the fuel tank or other plumbing. I then replaced the engine with the fuel lines connected and pressurized the tank system to about 9lbs and traced the leak to the carb. When I advanced the throttle the air all shot right out of the carb. I tested this against a known good YS enbgine and tank setup and the good setup did not lose any air when the throttle was advanced.

Is the regulater the problem or could it be the throttle barrel seal?

This is a 110 that I bought new off of ebay but, the previous owner had had the motor for a couple of years that never got used on his planned project.

I have a YS 91 FZ. Too much fuel mid range. It just floods out. I've been to the YS performance site and adjusted (regulator) just as they say. It seems that the regulator isn't responing to my adjustments. Anyone out there have any suggestions? I was thinking about replacing the plunger and spring in the regulator. It seems like it doesn't want to shut down the fuel.????