Having a problem with my 3W, but I'm sure it's my fault. I just got this engine used a month ago- ran OK, not great but I didn't want to tune it at that time. Then it sat around the garage while it's new airframe was getting worked on. Now it's in the plane, and it ran OK again(rich I think). But now all of a sudden I'm having problems trying to get it to start, and when it finally starts the engine runs for 10 seconds, then stops as if it runs the gas from the choke and that's it. If I give it throttle it dies instantly. It does this everytime, I put the needles back to stock settings(what I think is stock = 1 3/4 low, 3/4 high - Tillotson carb. Anyone have any suggestions? Thank you.

Sounds like you need to check the sealing on everything from the reed block housing down to the carb block. And make sure your Ryton block isn't cracked somewhere. You'll have to look close to see if it is. As a general rule if you see wetness on the sides of the reed block assembly you more than likely have a leak. Everything should be nice and dry.

Rich

Back out the low speed needle to about 2 -2-1/2 turns. Start engine and start leaning down low speed to where the engine wants to be according to transition...

I checked plugs and they were fouled - giving off no spark, but still in good condition. Sandpapered them, and got a spark. She's running like clockwork now, pulls so hard a few small trees 50ft behind the plane are moving pretty good at full throttle. Thank you for your suggestions

Fouled both plugs? go buy a lottery ticket, your pulling the winning odds glad to here its back and running

Yes I guess I was running way rich, but I don't have too much experience with gas. Maybe this makes sense, since I was only taching 5100 with a 3W 32x10. I was told these engines with cans should be running around 6K. But the tach is a 6 year old glow bee little pee wee tach I didn't think it was right, because I don't see how it could be that much more powerfull - my 2 buddies standing on each stab half have freakin line bruises on their calves from doing a few full throttle pulls - much more powerful than my 3W140. The first flight of my 40% 3W 330S is today!

Well guys the problem came back. I am thinking the "fouled plugs" are really just a symptom and not the actual cause. I put in 2 good flights and the engine was running fine, but even leaned as much as I could I only tached 5300 on a 3W 32x10 with 2 different tachs. After the 2nd flight I waited about 45 min then tried to start her up, not even a pop - completely dead. And I'm willing to bet the same thing happened to me the other day, and the fact that I kept choking her, and trying unsuccessfuly so many times was enough to make the plugs all wet and dark.

I was told by the seller that the engine only had about 5 gallons through it, but I didn't believe the guy. I got it so cheap I didn't care, but I'm starting to think he's right and it's still breaking in - hence the low readings. Or maybe whatever problem I have is making the engine a little weak. Anyone have any ideas why this is happening, bad ignition/switch/module? I have no idea what the problem could be, but it never dies while it's running.

I got some bad gas in my motorcycle last winter and it fouled the plugs similar to what you describe. I don't know what was in it but after I drained the tank and put new plugs in it ran fine. Just a thought.

That's a good suggestion, but I am using completely different gas from when I first had this problem and then today. I actually thought the gas might be it so I changed it all out and it still wasn't running until I cleaned the plugs.

Steve, 5300 rpms on the 3W 32x10 is fine. The prop is a HUGE load and my QS150 turned it the same so don't fret it. Personally I'd go with a much less loaded prop. If sound is an issue try a FUCHS 32x12 (mine tachs 5800) or even a FUCHS 33x12. A Mezlik 32x10 would be good too and cheaper. But again the 3W 32x10 is a very heavy load for your motor. Mine is hanging on the wall until my 3W157 arrives and even then I won't run it until the motor is well broken in.

Rich

I have a Bolly 32x10 laying around, seems to be thinner than the 3W. Would you reccomend switching to that? Sound is not an issue. Has anyone had a similar issue with their engine?

The Bolly would be perfect!

I was thinking maybe it's a heating issue. I bought the plane and engine together and havn't touched the module and I assume it was working fine before- it is placed on top of the engine box. Maybe the 3W prop was loading the engine so much it overheated the module after awhile? I'm also running a 6 volts regulated to the module, but it has warnings to not exceed 4.8. I know alot of ppl run 6. Maybe the combination of those two variables is doing it in. So far, It only acts up after the engine has been running for a while but not while it is running.

I have 3W 32x10 prop. I've run it on my DA150 and boy did the engine not like that prop, it never seemed to unload or even get close to its power band rpm. I have the engine on a TOC 40% Yak on cans. I am running a Bolly carbon 31.5x11 QQ and the engine spins the snot out of this prop, and yes, it is a LITTLE loud he he, but it pulls well on uplines. I cut 1/2" of each tip, reshaped and balanced the prop, and the DA150 is still not happy with this prop.
DKjens

If it's fouling the plugs in that short order, the spark might be very weak, or more likely the plugs are too cold of a heat range. Ray

I put the bolly on and the problem went away. I'm thinking the 3W prop put too much load on the engine, overheating it and killing the ignition after a while. That's the best theory I could come up with. Thanks alot for all who helped...