ok here i go again: have fresh fuel just opened the gallon up. i cleaned the regulator assembly and found just alittle jum deposit on the regulator plunger and now it's spotless. the first problem is when i fuel it up there is fuel running out of the carb and i can see it going thru the line. second problem i can get it down to 2500 rpm and it will start to shake and sputter and than die. when i diconnect the glow driver at a idle after starting it up and letting it run for 15-30 seconds and take the glow driver off it will drop 500-700 rpm. the motor started really good if when i fuel it and diconnect the fuel line to the carb body and replace it just before i start it. also i turned in the regulator adj screw so it is now just below the top of regulator body and when i shut it down there is no more 1 drop of fuel that come out of the carb. so what is the problem with fuel running out of the carb when fueling? i did screw the adjustment screw all the way down once when fueling and that stopped the fuel for getting to the carb. anybody have any ideas?

OK, so just so I am straight on this, when you fuel the engine fuel runs out of the carburator. Does it do it no matter what position the propeelor is in? Prop vertical as opposed to horizontal?

i did not check that. didn't even think that would made any differnce, i'll try that tomarrow.

In some cases, the diaphragm can be under pressure depending on the position or the piston and the rotary valve. That could be enough to prop the regulator plunger open.

well i gave it a try today. the results: while fueling it up it did not matter what position the prop/ cranshaft was in fuel was still getting into the carb. first time i opened the throttle there was close to a teaspoon full of fuel that came out.[&o] so i pulled the plug and it was soaked. so i disconnect the fuel line to the carb and with the glow plug removed and hit it with the starter to clear it out, while spinning the motor over fuel was coming out of the nipple like there was no tomarrow. so anyway i reinstalled the plug and left the line off, the motor ran until the extra fuel was burned off, than rehooked the fuel line the engine came to life like it should. it was loading up at a lower rpm 2800-3600 could not get it to hold a steady idle it's always changes several hundred rpm's. so i ran the engine up and it peaked close to 8900 rpm backed the needle off 2 -3 clicks and throttle back down to idle, which was around 2800-2900 than dropped down lower to2500 rpm but really sounded loaded up but it stayed running. so i flew close to one tank load.
so i tried the refuel thing again; well it put fuel right back into the carb again no matter what position the prop was in so if i want to start this engine i have to pinch off the line that goes to the carb to do it. one other thing is i tried to defuel it and the fuel line that goes to the carb was off and i could not get the fuel to draw out of the tank, i put the line back on and could get the fuel out and could see it was sucking the fuel out of the carb line and could hear air going back thru the carb throat and see air bubbles going back thru the fuel line. so some where the fuel flow is not getting shut off when it needs to be. the diaphragm looks like there are no holes in it. with the regulator body off i rolled the engine over by hand and could see the diaphragm working the way it should. do i need to just send it to ys and let them have at it? or should i try some other stuff? one last thing i also turned the regulator abjustment screw all the way down and when fueling the tank there was fuel still getting into the carb.

You have something terribly amiss if you are fully closing the regulator and fuel is still getting by; either your regulator planger is not closing fully due to some reason, the regulaotr spring is gone south or something else that we just are missing. I'd box it up and send it to YS Parts and Service. Richard and his crew will get it right.

i do not know what the free length of the spring should be but it looked ok. that is what i thought if i screwed the regulator all the way in it should of shut the fuel flow off. well i guess it's off to ys with it.

Sounds to me like it might be plumbed wrong...

i thought of that to so last night i went and double checked it than went and poured another cup of joe and went back and checked it again. it's plumbed just like it shows in the manual and the check valve is on the correct hose and going the right direction. since day one there are fuel filters on both lines.

i just got off of the phone with ys and the spring under the regulator screw was resversed, the taper of the spring was backwards, now upon fueling it i'm not getting any fuel past the regulator system. i screwed the regulator all the way down and tried fueling it and defueling it. than i tried it with the regulator screw flush with the regulator body and now it's working the way it should. once it's gets above 32 degress i'll go out and try to start it. hopping for the best

Good to hear you have that fuel leak sorted. I'm sure glad I don't live in your neck of the woods...I was complaining about it being cold at 57 yesterday.

glad i didn't have my hopes to high. with the regulalotor turned in all the way and hit it with the starter it will still pass fuel. i spent over a hour and still will not start. it got so bad that i used up 2 glow drivers and killed the battery on the riding lawn mower using the hand starter.[:'(] i played with the regulator all the time still getting fuel out the carb. the engine never even ccoughed or sputter. tried several different plugs os and ys. [:'(] this thing is going to ys or in the bottom of the lake.

Try this. Remove the regulator and disassemble it. Clean everything with glow fuel. Make sure to rub the diaphragm between you fingers while covered with fuel. Do the same with the plunger. inspect the area around the hole that the plunger fits into. Now assemble the plunger and pin through the hole in the regulator and make sure the pin is completely inserted into the plunger. Now slip the small end of the spring over the nipple on the plunger and screw in the adjustment screw. I try blowing into the small hole next to the diaphragm and see if the plunger is holding. One hole just goes into the diaphragm chamber but the other should hold pressure until you press on the plunger pin. carefully replace the diaphragm and tighten the regulator back onto the engine. I bet that fixes you problem.

Blessings, Terry

is the small end of the spring soppose to be over the nipple of the plunger?? i put it back together with the small end resting on the top of the nipple. didn't have time to look at it yesterday.

Yes, the small end of the spring should just fit over the nipple. If it doesn't, perhaps the plunger is swollen. That might explain why it is not seating properly.

when i get acouple more cups of coffoe i'll go and take alook at it

It could very well be the case that the plug is flooded, which makes start impossible.

When the throttle is at idle, the fuel is supposedly drawn to the carb. You may want to turn the regulator screw 1//4 or even 1/2 turn in to help "shut down" the regulator during the idle.

Also, make sure the tank can hold the pressure: 10 flips on prop. wait for a hour and disconnect at the one-way valve. Should feel a strong puff of air coming out of the tank.

ok i tried it again, never got a sputter[:'(]. after it sat overnight i completly tore apart the pump system. the only thing that i noticed is the hole for the plunger allows a lot of play. not in and out but the diameter of the hole. the plunger can move freely. also when i fueled it up it did not let fuel by, but it only took 1 revelution of the prop/ crankshaft to draw fuel to the carb. the glow drivers where charged up overnight and will glow the plugs really good i tried several plugs. i also screwed the regulator screw all the way in and the glow plug was removed rolled the engine over by hand and fuel would squirt out of the niple that goes to the carb but only at certian pionts of reviloution.[&o]. i also heard some clatter in the engine. i wonder if the intake or exhust valve/pushrod or rocker arm needs to be looked at? it would make sense if either valve is noy opening or working right it will cause it not to do anything. the plane has been setting for 1 hour and when i pulled the tank vent plug there was still pressure in the system

The plunger should move up and down, via the diaphragm. and the small brass T thing. The plunger should completely plug the hole, with the help from the spring, and when the engine is not running, or at idle. If that is not the case, then definitely there is an issue here.

Is the plunger in good shape? You may test it by taking the regulator out of the engine, take the screw out, fill the cavity with some glow fuel while holding spring in place. The fuel should not leak out from that hole.

i'll go give that a try after lunch, i'm really tempted to take the valve cover off and take alook , it will not hurt to do that if that clatter is from a pushrod that is loose or a rocker arm is not adjusted/ locknut came loose. i should be able to get some sort of cough or sputter from this motor. i have overhauled several chevy smallblocks/mopar and ford. also i have pulled inframes on cat 3406b/c models and one seris 60 detroit diesel engines. so i'll finish lunch and go back outside and have some fun just wish it was warmer than 37 degrees out.

ok nonstoprc i did what you recommended. if i covered the small hole that that is on the base of the regulator the plunger with just the weight of the spring it would hold fuel. the small hole that i'm talking about is the feed hole for the nipple/fuel line that goes to the carb. i reassmbled the regulator again. took the valve cover off and checked the rocker arms/ valve springs/ pushrods they all checked out. i also screwed the regulator screw down all the way and rolled the engine over by hand and still there was fuel getting past the regulator system[:'(] anybody have a idea?? i'm at a loss with this.

well it finally started: but the throttle had to at wide open to do it. i thought i'd try that as a last ditch try. i ran it at idle for 20 or so seconds, ran it up to full throttle slowly and set the high speed needle. rpm of 8500 + or- 100 rpm. than tried to set low end every time the engine would get around 28-2900 rpm it will shut itself off just like you turned off a switch. i also noticed that if the glow plug driver was removed at or around the same rpm the engine would shut off. anybody have any ideas? i guess that in the future that inorder to start this engine to do so at a near full throttle position. i do not like to do that.
the low speed needle is set at 1-1/2 turns out

well i just got back in from trying to start it again. it would not start; pumping fuel hard with reg closed all the way down/ and full throttle fuel poured out of the carb. this engine is going to ys i'm tired of have to waste time on this engine.[:'(][:'(][:'(][:'(][:'(]

Without being there to see it, it is tough to tell. The regulator is obviously not working properly. My best guess is that the plunger pin is not seated completely into the plunger so that the diaphragm is pushing the plunger open even at rest. Everything you have posted suggests that the plunger is not seating and letting too much fuel by. My best guess is that something is in the hole in the plunger that is stopping the pin from fully seating into the plunger. Let us know what YS finds. It will help the next guy.

Blessings, Terry

Have you confirmed that the regulator housing is not installed backwards? If you're not sure, unmount it and rotate it 180 degrees and reinstall. Having the housing backwards can cause these kinds of problems.