Folks, I need a bit of help here as I am out of idea's

I have a low time (roughly 7 gallons) 3W 55i that I bought new this year. From day one this engine has been hard to start but it had already ran well once started. One day all it would do was fire after choking then turn the choke off and as soon as it burned what was in the engine it would stop and I'd have to choke it again but it still would not run past one or two seconds.

BTW I would always have to squirt fuel directly into the carb to get it to fire for the first time of the day so that it would start to pull fuel. After that it was OK not great but OK. Also both needles have always dripped fuel as long as fuel was in the carb.

Well one day last month I could not get it to run for more than a second or two no matter what so I sent it back to Aircraft International. They replaced the hall sensor and reeds and said it ran great.

Last weekend I finally had the time to reinstall it. Well needless to say I had the exact same issues. Would not pull full until I primed it and once it would run it would only run for a second or two. So I go out and get a gasket kit and replace them and now it pulls fuel really well but I still have the same issues.

So over the last few evenings, I have tried it by connecting the battery directly to the switch, changed the battery 4 different times. 2 were Fromeco 2400's and one was an Expert 6V 2700 and the other was a NoBS 6v 1500 high rate. Both Fromeco's were taken out of another plane that I fly a lot to test with. The two NICD batteries were bought brand new for this test. I've also tried a new fuel setup as well as connecting the carb directly to my fuel can. This all was tried on a test stand as well

I'm thinking that since the needles wobble a little bit when 3/4ths to one full turn out that is my problem.

BTW, the engine is installed inverted so the needles are pointing down inside the engine box and that is how I can tell they are dripping fuel. I have tried the needles at the manual setting to 2 full turns open

AI is swearing that it is my setup so I thought I would try something else. I decided to mount a Brison 3.2 using the original of everything except for the exhaust system and guess what, it ran just fine.

Can anyone think of anything else to try.

I'm trying to work with AI to resolve this. I also want to make it clear that they are being friendly and as helpful as possible but it does seem they refuse to believe I am having this issue as they say a lot that it was fine in their shop. I'm betting they had it in their test stand right side up so the needles were pointing up

I have mine installed inverted and the needles are tight (no drip). I would suspect something is wrong with the needles if fuel is dripping from them. The 55i is a strong and great running engine, mine starts and runs better than my DA 50.

How about trying teflon tape on the needles to see if they seat better?

That's a possibility. I would have to be very careful to not let any get into the carb or I'll have even more problems but I will keep it in mind.

I went through about 3 gallons right after I put it on the KS1060 pipe and it hauled this 19lb Yak around like gravity was a passing fad so it makes loads of power when it did run.

Be careful on the teflon tape. If one little piece gets loose, it will plug the port that the fuel goes through.......Not a good idea. I had one of the early DA50's, they were putting a bit of lock-tite or something on the needles........yep, after turning them a few times, the carb got plugged... I'm running the 3w80XI and have had no problems with fuel dripping out of my needles, but they are horizontal when the engine is mounted inverted. I had a Johnsered chainsaw years ago that had o-rings on the needles to prevent air from being sucked in. If fuel is dripping out of the needles, sounds like your diaphragm needle is sticking open, or has some trash under it. That's the first place I would look. You do have an odd problem here.


You shouldn't have to squirt fuel into the carb to get it started the first run of the day. Check and make sure your choke butterfly is closing all the way. All it takes is a hair open and they won't draw fuel near as well...

Frank

I have replaced all of the gaskets and pump in the carb and it now draws fuel really well. I also have the 80xi-CS in a WH Edge540 that has run perfect since day one. It start the exact same everytime

I can put my finger on each needle and wiggle it a very tiny bit but on my 80 they do not move at all. I have even gone as far as stretching the spring to try to get it to tighten with now luck

bubba,

ok the carb is drawing fuel to prime now, but you're still dripping fuel out of the needles. And when the engine starts, it just burns the prime and quits.........Correct?

Running on prime and quitting means lose of vacuum to operate the carb diaphragm..... or plugged carb........but the carb will draw fuel to prime....(real head scratcher) If the reeds have just been replaced, that shouldn't be it.

Needles dripping fuel.........I've never seen this on any 2 stroke I've ever owned. [:@] My one chainsaw with the o-rings on the needles had a bad o-ring once and would lean out and die. Drove me crazy finding it.

Any chance you got an extra carb laying around you could try?

Were's Ralph when you need him.

Correct

That could be a bad ignition/battery/switch also but all of that has been replaced with the exception of the ignition module itself

Don't get me wrong, it may drp one drop every minute or two. I just checked the needles to wobble like 1mm. I also looked at the needles themselves and noticed they are different sizes. The high speed needle has a nice long point on it and the low speed needle has a short stubby point on it. I'm wondering if they are in backwards. I never removed them that I can actually remember


I wish I had another carb to use, that would answer this once and for all and I agree I would love to see Ralph pop in here.

I just got an email from AI and they want it back. They gave me the exact procedure they used to test it and according to the email it gave them no problems. The real problem is they close on Friday until Jan 2 2007 so I'll have to wait until then to send it back, but if I can find the solution before hand then I would be happy with that. I don;t mind doing the work it's just that I'm out of idea's

Let me reiterate, Gerhard is trying his best to work with me on this, I've been pretty busy these last few days and did not realize they were open until 10pm. What's nice is they are around 100 miles from me so any shipping via ground is usually there/here overnight

The needles on the 3w80xi can't be reversed.......different thread size. Don't know about the 55.. The needles on my 3w80 had a bit more slop than I would have liked. Wonder if this is common with the Tiltson carbs?

Be sure to keep us posted on how this one turns out. Bound to be something simple.

Glad to here AI is working with you.

Frank,

Man I just re-read my posts and I really need to proof-read before I hit the OK button. [:@]

Anyway, I just got off the phone with AI. He gave me some things to look for in the carb on the pump side and he even suggested the teflon tape.

I never bothered to look at the threads to see if they were the same on the needles but I will the next time I go to look at the engine again

Carb needles don't drip fuel when the carb is working correctly...Most likely cause is the inlet needle not seating...You should get the carb checked with a pressure gauge, it should hold at least 8 lbs pressure indefinitely...Small engine shops have the tester....

I'm not sure about the fuel dripping from the needles, but your issue with the engine starting and stopping after a few seconds is exactly what my 3W-50i was doing a few weeks ago. I literallly spent two days flipping the prop till by arm and shoulder were sore and stiff! Fuel was dribbling out the carb, I had to pull the plug every few minutes to drain the excess fuel -- it was awful! I sent the motor to Cactus and they pulled the carb and isolator block and sealed the joint between the crankcase and the block with Loctite 518, which is an anaerobic gasket maker, and that engine now starts easily and runs beautifully. Yesterday I started it up on the stand, just to enjoy the ease of starting! I am going to give all my gas engines the sealant treatment after this. Bobby cautioned me not to overtighten the bolts holding the block on, so when I resealed my other 3w-50i block, I just snugged them to tight and used some loctite blue on them. If you haven't tried this, it doesn't take long and may make a difference.
Good luck,
sam

Sam,

According to AI, that is exactly what they did when they replaced the reeds....

When I get home today I plan on digging a little deeper to make sure it things that were listed on the work order were actually done. I'm convinced it is either a carb problem or air leak between the carb and engine considering everything else that I and AI have done...

I'm almost thinking the reeds have a problem like not closing fully.

I still appreciate the info though.

If you pull the carb and block, you should be able to get an idea of the condition of the reeds, although I don't know how you'd tell if they were really sealing or not -- when I took my block off that was the first time I'd tried it with a 3W, and I've never even seen a reed block before, much less know how they work. Bobby also mentioned that my engine was leaking a little bit of air at the fuel intake, but I don't know what he did for that. When I spoke to him it sounded like that kind of a leak may or may not have contributed to the hard starting and not running more than a second or two. Permatex markets the same sealant under a different name, in a blue tube, but its the same stuff. I'd sure give it a try before anything else.
Good luck, and don't let it dampen your Christmas spirit!
Sam

Thanks Sam,

I won't dampen my spirit at all. I was hoping to take this plane on a trip with me down south since it's one of the better flying planes. No matter, I have 3 other GS ones that can go with me as well.

I have a similar problem with my 3W-75i US TOC. This thing just runs real fat now no matter what I do. In fact it drips fuel like a drop a second while it is running. Something is defiantly wrong though, it used to run awesome and just sip fuel. I could fly for over 22 min on 24 oz of fuel with some to spare.

I have the same problem with the needles but I send the motor back and they just stretched the spring and said it ran fine. No Joy. I put it back on and had the same problems. I got so frustrated the airplane sat on the shelf all summer. Shame, waist of a good airplane, I’ve got the hankering to get it fixed now – thus I found your thread. I’m going to pull the carburetor and see what gives. Let me know what you find.
Regards,
Rick P

Hi RickP and happy holidays. What service are you using? AI or Cactus? Sound like you are on to the problem. Carburation and or leakage around the block. I remember when that 75 was on sale for a great price. I was tempted but waited for DA to make a 75.
Good luck Bubba! Git done!

joe

And where is this DA75? I've been waiting......

Are you turning blue yet from holding your breath....I would love to see a DA75

RickP,

If you sent it to AI I would verify what they did. I can speak from experience on this one. Please understand I am not trashing AI at this point in time. Last evening, I pulled the carb/carb block back off and here is what I found.

According to a phone call I had with AI, they used Loctite 518 to reseal the carb block to the crankcase, I found no hint of it. I have not been able to get the engine to run for more than a second or two but they said they had it running multiple times over the course of a half hour but even still that should not have burned it off. They did replace the reeds as they said. I also know they replaced the hall sensor as that is obvious.

I did what Ralph suggested which was the same thing AI suggested and no go and all this was done again on my test stand and not in the plane.

I called Bobby at Cactus and he thinks I am looking at something seriously wrong in the carb if not the ignition itself. He is sending me a new carb which went out last night but considering the holidays I will not see it until late next week, if I'm lucky. Oh well... If that does not do it then we'll look at the ignition next. We're doing the carb first because he believes that since I am getting drips from the needles it's an air leak problem.

Bubba
Good for you! I've had good experience with Bobby. As the for Loctite 518, I could see some red around the edges of the carb block/crankcase seal when I got the one engine back from Cactus, and when I resealed my other engine myself, I put a thin coating of the 518 on one surface, and when I tightened it down it squished out of the joint, leaving the same red line as the other engine. So, I would have thought that if your engine had received the same treatment, it would have had the same red sealant around the joint. Please keep us informed as to your progress.
Sam

Sam,

If I would have seen the red around the block I probably would have never removed it but I am glad I did.

It will be next week before I do anything else at this point

bubba,

Sounds like you're getting a bit closer...... I bet the new carb, along with some sealer actually being put on the carb spacer, she'll be running as good as new.......

I sure hope so... I do like the way this engine flies the plane it belongs in

I had the same problem with a 3w 60. It turns out, I had the throttle plate flipped around backwards. It apparently affects the needles.

Guys,
I am using AI. They said they streched the needle springs to keep the needle from backing out. No doubt they did this, plus they said they had it running and tuned it. I do not beleive they did this. First off, I forgot to send the muffler and don't see how they could honestly tune it without one. I was kind of disappointed because with all the shipping and charges it cost me $65 dollars or something like that for no difference.

Anyway, I finally got the bird on the bench and took off the carburetor. My god, what a mess of junk I found in there. I suspect it will run fine now, Gotta wait for good weather now :-(

That DA-75 has been "ready" for over 3 years now. Don't believe it. however, the DA-50 and tuned pipe might be an option. I had it on this airplane first and it worked well. I got rid of it because of the "rod" issue (I had it go bad twice), now fixed though - I don't know if the pipe made this problem worse at first.

RickP