Discussion in 'Engines' started by yakken, Feb 21, 2012.
thats a very interesting read. thanks for posting that.
i think we are going to give it a try.
I have had to do the Static pressure Tube mod to a few installs recently. I think it is partly because I am using the cooling air inlet and exit baffles to better use nowadays and partly because some engines are more finicky than others on tuning issues.
I prefer the way 3w deals with it. Tube from the diaphragm cover to an inlet on the intake snorkel. You can do the same thing by putting the open end of the tube right at the carb opening.
that seems like the best method. never tried it but i have wondered why no one else does it.
Will that fit the carb on the 170 or should we get the bigger size?
here is one on a Slick,it just eliminates any pressure problems when tuning carb.
That is the large one, should fit the 170 no problem.
my brother built a real thin balsa box for the metering tube off the carb and mounted it inside the fuse. went to start the plane and had no spark. fooled around with it and found the connection to the hall sensor bad. so we might have had a ignition problem from the start. :banghead: after he fixed that we took it back out to the field and tuned it up in about five minutes. i flew the piss out of it and it was running great . :thumbsup: when i landed the plane we noticed that the canopy was shaking real bad. the dowl pins that hold the front of the canopy were mia. this plane has been a PITA but i think we will get it straightened out.
i had the same kind of thing before,,level flight ran great,but roll to the left or go inverted it would all but die,flip it back over and runs great,i finally found it had a bad jr connector between the ignition and the hall sensor ,,drove me nuts for a couple weeks
Flew the crap out of it today and no problems. Even Buttface approves this message. thanks everybody for all the great info and help. :thumbsup:
got another question. my buddy phil has a da 50r that quit in flight and now wont suck any fuel out of the tank. we checked the fuel lines and all thats good. this engine has about 500 flights on it. i pulled the carb apart and all looks good. diaphram is not busted and the reed valves look ok but i am not to familier with reed valves. any sugestions? also if we pour some fuel in the carb it will run till it runs out. we are going to try a new carb kit and clean the carb up. should we replace the reed valves and block? thanks
If the reed valves are flexible, not split or warped, and pretty close to closed, they are probably okay. If the engine runs when primed, I would be looking for a delivery problem in the carb. Plugged port, filter or bad pump diaphragm.
I noticed one reed valve was raised slightly.
All fixed now. Maybe Phil will come on here and comment on what he found. Lol
If there isn't a major blockage or a diaphragm issue in the carb, take another look at the fuel lines, especially for:
Tee's or filters between the clunk and the carb. If there are any, get rid of them.
Pinholes in the clunk line, including the metal tube that goes through the stopper. While the tank is open, replace the tubing anyway.
Correct plumbing connections (My son once accidentally connected the fill line to the carb instead of the clunk line. The engine stopped every time the plane was inverted - we don't use dual clunks, just a 90 degree bend on the fill line to the bottom of the tank).
Liquid in the fuel tank (there should be some, it is called fuel) - I have seen this issue before - the guy filled a different plane and had a brain fart.
Ok, this is going to be the year for engine problems.:banghead: my buddy Phil has a da50 that was running perfect until the other day. While flying, it lost the top end of the throttle like it was lean and it just died. It runs fine on the low side. Go above half throttle and it dies. This is what we have tried. Rebuilt carb, new reeds, plug, changed tank and all plumbing. Hard wired ignition. Ran tube off of carb. Doesn't matter what we do it will not run above half throttle. The high side needle doesn't seem to make any difference. The low side you can tune just like normal. I havent had to mess with the ignitions on one of these. Can I check it or what is your guys opinions.
When you rebuilt the card did you use carb cleaner remove the needles and blow out all the passages?
Reeds? That or like RTK says the high circuit could be plugged with a small piece of dirt. They can take some doing to remove. High pressure air or a hair sized wire. I had problems with Hayes neoprene clunk tubing filling up my carb screen. That was a beeotch to figure out. Hold your carb screen up to a light and look through it. Mine was plugged with a thin layer of something. Took some work to clean it out. Stuck to it. Now I only use Viton for clunk line.
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