Help with walbro carb
05-29-2015, 10:14 AM
#26
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Hi scubaozy,
maybe, I could reply in german, looking at your location.......
I had a Sukhoi 31 with a Zenoah 62 lying around for two years, with the landing gear torn out. You find this plane in my profile. I had not the desire to repair it until april, this year.
The engine, converted to a falkon electronic ignition, made some problems now.
To cut a long story short.....
Both screens in the carb were closed by sticky old oil. It was not enough to clean the bigger one, as I had to realize. The smaller one, hidden under a metal cover, was also closed. Maybe some of the small holes also.....
The local expert in chainsaws and other stuff gave me the right advice.
So I took off both covers of the walbro carb, pump-and regulating side. I kept the membrans and seals at home and gave the carb body to the expert. He cleaned it in an ultrasonic bath and took 10 bucks.
After assembling all pieces the engine and the plane performed like new. That was all.......
Maybe this can help you.......... aaaaaaand a repair kit could also be a good idea....
Pedro
maybe, I could reply in german, looking at your location.......
I had a Sukhoi 31 with a Zenoah 62 lying around for two years, with the landing gear torn out. You find this plane in my profile. I had not the desire to repair it until april, this year.
The engine, converted to a falkon electronic ignition, made some problems now.
To cut a long story short.....
Both screens in the carb were closed by sticky old oil. It was not enough to clean the bigger one, as I had to realize. The smaller one, hidden under a metal cover, was also closed. Maybe some of the small holes also.....
The local expert in chainsaws and other stuff gave me the right advice.
So I took off both covers of the walbro carb, pump-and regulating side. I kept the membrans and seals at home and gave the carb body to the expert. He cleaned it in an ultrasonic bath and took 10 bucks.
After assembling all pieces the engine and the plane performed like new. That was all.......
Maybe this can help you.......... aaaaaaand a repair kit could also be a good idea....
Pedro
Last edited by pedroaleman65; 05-29-2015 at 10:21 AM.
06-08-2015, 12:28 AM
#28
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Location: Berlin, GERMANY
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I have been testing the engine with various props this weekend after carb rebuild including 24x8, 23x10 and best I could get was 5500 rpm peak with a 22x10. I don't think anymore that the problem is on the carburetor. I have leaned it as much as I can to get this rpm and the engine was hot and spray from the carb was minimum. It did not fail due to heat but not sure would be trusting to fly with those needle settings. Someone in the club suggested that the muffler I have (Krumscheid banana) is quite restrictive, so, it is normal to get bad performance. I loosened the muffler (not removed fully) and I could get few hundred rpm more. I am open to the suggestions. I have last week bought another of the same engine second hand for a very reasonable price, so I will very likely swap the engines also ignition modules to see whether there will be any improvement. I am open to suggestions. I already got the suggestion "get a DLE 55" but putting in any other engine will require major surgery and this is a very rare plane, I really want to make it work as it is..
06-08-2015, 09:12 AM
#29
My Feedback: (19)
If you feel your carb issues are under control, here are a few more suggestions. First, the G-62 likes to turn up (higher RPM) and is very sensitive to prop loads. Loaded a bit to heavy and the RPMs will fall way down making one thing the engine has a problem. Your 22-10 should be about right but if it is a high load prop, that could still be a problem. Most anything 23" or 24" will be too large for the 62 though I'm sure there are exceptions. For a G-62 to be really happy, it needs to be turning from about 6500 RPM and up.
The G-62 is also very sensitive to mufflers and yes, yours may be too restrictive though I'm not at all familiar with your muffler. If you can get your hands on something else to try, that might be a good route to take.
You mentioned ignition modules so has this engine been converted to electronic ignition? If so, how is it timed? If timed with too little advance, your performance would be down.
Last and probably a question I should have asked first, is the engine in good mechanical condition? Does it have good compression when cranked? Does it turn freely? If these engines have ground contact with the prop, the crankshaft can twist fairly easy and an engine with twisted crank won't turn up as expected. You would also notice some runout at the prop tips and the engine would vibrate more than normal.
I hope some of this helped. These are darn good engines though they're not torquers like some of the rear intake, reed valve engines.
The G-62 is also very sensitive to mufflers and yes, yours may be too restrictive though I'm not at all familiar with your muffler. If you can get your hands on something else to try, that might be a good route to take.
You mentioned ignition modules so has this engine been converted to electronic ignition? If so, how is it timed? If timed with too little advance, your performance would be down.
Last and probably a question I should have asked first, is the engine in good mechanical condition? Does it have good compression when cranked? Does it turn freely? If these engines have ground contact with the prop, the crankshaft can twist fairly easy and an engine with twisted crank won't turn up as expected. You would also notice some runout at the prop tips and the engine would vibrate more than normal.
I hope some of this helped. These are darn good engines though they're not torquers like some of the rear intake, reed valve engines.
Last edited by Truckracer; 06-08-2015 at 09:15 AM.
06-08-2015, 02:52 PM
#30
If you feel your carb issues are under control, here are a few more suggestions. First, the G-62 likes to turn up (higher RPM) and is very sensitive to prop loads. Loaded a bit to heavy and the RPMs will fall way down making one thing the engine has a problem. Your 22-10 should be about right but if it is a high load prop, that could still be a problem. Most anything 23" or 24" will be too large for the 62 though I'm sure there are exceptions. For a G-62 to be really happy, it needs to be turning from about 6500 RPM and up.
The G-62 is also very sensitive to mufflers and yes, yours may be too restrictive though I'm not at all familiar with your muffler. If you can get your hands on something else to try, that might be a good route to take.
You mentioned ignition modules so has this engine been converted to electronic ignition? If so, how is it timed? If timed with too little advance, your performance would be down.
Last and probably a question I should have asked first, is the engine in good mechanical condition? Does it have good compression when cranked? Does it turn freely? If these engines have ground contact with the prop, the crankshaft can twist fairly easy and an engine with twisted crank won't turn up as expected. You would also notice some runout at the prop tips and the engine would vibrate more than normal.
I hope some of this helped. These are darn good engines though they're not torquers like some of the rear intake, reed valve engines.
The G-62 is also very sensitive to mufflers and yes, yours may be too restrictive though I'm not at all familiar with your muffler. If you can get your hands on something else to try, that might be a good route to take.
You mentioned ignition modules so has this engine been converted to electronic ignition? If so, how is it timed? If timed with too little advance, your performance would be down.
Last and probably a question I should have asked first, is the engine in good mechanical condition? Does it have good compression when cranked? Does it turn freely? If these engines have ground contact with the prop, the crankshaft can twist fairly easy and an engine with twisted crank won't turn up as expected. You would also notice some runout at the prop tips and the engine would vibrate more than normal.
I hope some of this helped. These are darn good engines though they're not torquers like some of the rear intake, reed valve engines.
06-08-2015, 11:38 PM
#32
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I think your comments are valid, this engine is also has industrial engine roots like G62 in likes to rev high. Tested engine is nearly brand new, never been in the air, the second one I got has around 30 flights on it according to previous owner and both of them has a lot of compression. I have installed the second engine after work. I will test and later swap the ignition and carburetor to isolate the problem. I might try 22x8 to get a bit more rev.
06-09-2015, 05:13 AM
#33
The choke butterfly valve is quite restrictive on some of these. Maybe that could be removed or modified. Also it could be run with no muffler quickly just to test.
