bhall01

My Feedback: (4)

I have a 3W 106 now on it's third season. Due to extreme frustration in being unable to get the darn thing to run well inverted - what seems to be the 'classic' going rich - I'll bet the engine doesn't even have 5 gallons of gas through it. Honestly. Tried everything. No luck.

Ended up getting a Walbro SDC-80 carb from RCIGN, seemed to help, definitely easier to adjust than the Tillotson. Better, but still not good enough to trust to really wring out the plane. Added a 3W 'snorkle' - the older style with the large opening. Seemed to just about have it - down to a point where the 'rich' condition seemed to happen at only 1 or 2 throttle 'clicks'.... we darn near had it. One bad landing and a nose-over later, the snorkle was toast. Got a new snorkel, the newer style with a 'reducer' glued into the opening. Now it seems worse than ever, can't even get close to where it was before.

Been reading some about the 'balsa box' fix..... can someone - RTK?- give some details? Did some searching, seems like the 1-1/2" cube is about the size, but there seems to be some discrepancy as to whether or not the box is ventilated or not. Some say sealed, some say small vent hole. Please advise. Location and distance from the carb make any difference? I guess the next step is to get rid of the snorkle and try the 'box'.

Also, with as little run-time as this motor has had, it seems to be leaking a little from one side of the front of the crankcase. I asked the Aircraft International guys about this while I was at Joe Nall. The fellow (Steve, I think) said that it would not hurt the motor or affect the run, but that it wasn't going to get better and that I could send it in for service to be resealed at my convenience...... so I doubt that this is contributing to the adjustment issues, any thoughts on that? He also said that "yeah, the factory is stingy on the sealant sometimes, send it in we'll reseal it and it WON'T leak when I get it back".... and that it wouldn't be that expensive a repair...... raises a couple questions - 1.) anybody out there have any idea how much that might cost? 2.) Can I do it myself? I'm not worried about the 'mechanics' of breaking down the engine, but I think I've read something about the bearing being held in place with loctite?? A little concerned about getting that right. And finally 3.) If the 'factory authorized service center' is acknowledging that the factory is sometimes stingy with the sealant..... wouldn't you think that should be a warranty repair, regardless of how old the engine is and not a "not that expensive of a repair" -- just ran out of the warranty period, but like I said, has very little run on it.

I guess what I'm at a point where what I'd REALLY like is to just get another DA-100..... never had a minutes trouble with that one, only had to adjust the needles twice since I got it new - it just runs.... just hard to swallow spending the money to 'retire' what should have been a good motor and turn it in to a paperweight..... very frustrating...... say - anyone out there want a good deal on a slightly used 3W 106? Seriously.

Oh well - sorry so long.... I'm open to any advice you may be able to offer. Like I say, I guess the 'box' is the next thing to try.

Thanks --
BJH [sm=drowning.gif]

Meesh

My Feedback: (135)

BJH

In general reference to Crankcase leaks on 2 stroke engines.

If you have leaks they won't run well. Ask anyone that rides a 2 stroke Dirt Bike. Sealing the crankcase is probably the most important thing to do.

Bob

Tired Old Man

My Feedback: (1)

I'm surprised that Ralph (RTK) has not already replied to you. The box that Ralph built to cure his condition is not "vented" to the atmosphere in any intentional manner. It wasn't built "air tight" either. Just a rough box tossed together with the line running into it that avoided any positive or negative pressurized air. The distance from the carb is irrevalent. I fly with Ralph all the time when I get the chance, and was present when he made the "box" discovery.

As far as the case leak is concerned, unless you are pretty good with small engines and tools you'd probably be better off sending it to Cactus or RCIGN. Both do the work well. There are quite a few situations where bearings and sleeves are retained in engines with a special type of Locktite. If the 3W is using that method, I would not recommend tearing into the engine in any manner that would displace the bearing. The cost of round trip shipping with insurance will probably exceed the cost of the repair.

Pat

RTK

My Feedback: (1)

Thanx Pat, I must have missed this thread.

Pat (Silversurfer) summed it up well. My little box is made of balsa with no holes to the atmosphere, only one line going into it. The dimensions are about 1-1.5 inches square. I had talked to 3W about this problem and they wanted me to box the whole carb. I did not want to go thru that much trouble so I made my little box. I know my engine was going rich because it was fine in level flight and on the ground, there wasn't much else it could be but a pressure problem. For some reason the Tillotson carbs seem much more sensitive to certain conditions than Walbros.

If the crankcase leak gets much worse send it to RCIGN1, he does a lot of repairs on 3W's. You will not find a better guy to deal with and your engine might end up there if you send it to a 3W dealer anyway.

Good luck, and I hope it all works out for you.
Ralph

Diablo-RCU

My Feedback: (1)

If oil is leaking out of the crankcase, air is leaking in....and that makes a two stroke run poorly. Send it in for repairs and have them replace the front two bearings while they're at it. They are sealed bearings (fairly inexpensive). Check carefully to make sure you don't have oil leaking out from the crankcase at some other point - sometimes the castings are porous and can leak air. If you find an oil leak at a porosity, circle it with a black magic marker and suggest they replace the case under warranty.

RTK

My Feedback: (1)

If the leak is just a "little" wetness (moisture spot), it should not be a problem. If the pulse pressure is blowing thru, it must be fixed. First check to make sure ALL the bolts on the whole engine are tight. Loose head bolts have been known to break. Where abouts on the front of the engine is it leaking???
In the end it should be fixed anyway. I hope the machining on the casing is true.

Tired Old Man

My Feedback: (1)

Ralph,

'Bout time you showed up for work in this one. I didn't want to be the one to make a note of who works on what out there, but I'm happy you did. Saves a lot of time in the long run. I'll be out of here somewhere between the 3rd and 5th for 6 weeks of "play time". I'll prolly need your assistance this time.

Pat

bhall01

My Feedback: (4)

Thanks for the info and suggestions replied so far - much appreciated. Sounds like the first thing to do is get the leakage fixed before worrying about anything else.

Not really bad leakage, but it appears to be coming from the case seam from the cylinder to the prop hub - right side of the engine, when viewed from the front. The engine has baffles above and below. What you see after a flight is a 'spray' of oily film on the lower right baffle.... nothing on the left side and little or none on the upper right. Didn't do that when new, and it appears to be gradually worsening. Case bolts are tight. Had the cowl off earlier this season and when the engine was running you could see an ooze of wetness on that seam.... would blow a small bubble once in awhile, so I'd say that's where the leak is!!

I guess while the "patient is on the table" I should go ahead and get the front bearings replaced too...... looks like that's the plan. I'll try and contact RCIGN and get on his repair list. When it get's back I'll try the balsa box set-up.

Thanks to all once again!

Barry.

bdbd

My Feedback: (62)

Ok,tried it all, balsa box, trumpet both facing rearward and forward, no trumpet, leaning needles untill poor performance low end and high end. I have a Quique yak 102" cannister mufflers does the standard bad things. Runs great on the ground, sluggish on takeoff untill turned skyward runs great throughout rightside up and knife edge but turn this baby inverted near 1/2 throttle and starts to loose rpm. Don't move the throttle and roll right side up and goes back to running perfectly. What gives with this engine. BTW I have the new style trumpet with the insert to reduce the opening. Any ideas??????

blikseme300

My Feedback: (118)

I can't take it anymore! Send it to Ralph. The "spray of oil" you mention seems to point to real trouble, sooner or later.

Safe Flying!

ljones5000

My Feedback: (2)

With respect to the balsa box, I tried it on one of my engines. It just seemed there should be some opening to the atmosphere so I drilled a small hole in the box. The engine ran the same with the hole to the atmosphere or with the box entirely closed to the atmosphere. Absolutely no difference. Anyway, it's a very simple thing to do. Drill a hole in the box and if it doesn't change anything plug the hole.

Larry