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Jan 21, 2020, 01:22 AM
Still gassin' it.
Quote:
Originally Posted by SeismicCWave
I think that has to do with the extremely fine thread on their needles. Dub Jett uses the same kind of needles on his engines and his carburetors are also very very nice and easy to adjust.
That, and the lack of a ratchet, so you can get at all the intermediate positions...
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Jan 21, 2020, 01:49 AM
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Quote:
Originally Posted by 1967Brutus
That, and the lack of a ratchet, so you can get at all the intermediate positions...
Some of the newer ones have ratchet. The older ones have the lock nut to hold the needle with friction.
Jan 21, 2020, 01:49 PM
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You might make a nice gasket out of aluminum tape. I've done it and it works great. Clean the area off you want the gasket, put down a large piece of tape over it, burnish it down, then cut out all the openings with an exacto knife. two minute job.

If you get yours to run reliably on glo with no spark plugs and no dropping out of that left cylinder, I'm going to have to drag my 1.20 back out. I've got an OS 7D carb for it and I believe I made an adapter plate as well. Just haven't put it all back together.

I sort of remember reading somewhere that in order to fix the cylinder dropping out requires machining of the intake ports going to that dry cylinder. That or possibly a baffle to route some fuel to it. I tried opening up the reed valve area but it made no difference.

Good luck and post back your results.

carl
Jan 21, 2020, 02:16 PM
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Quote:
Originally Posted by carlgrover
You might make a nice gasket out of aluminum tape. I've done it and it works great. Clean the area off you want the gasket, put down a large piece of tape over it, burnish it down, then cut out all the openings with an exacto knife. two minute job.

If you get yours to run reliably on glo with no spark plugs and no dropping out of that left cylinder, I'm going to have to drag my 1.20 back out. I've got an OS 7D carb for it and I believe I made an adapter plate as well. Just haven't put it all back together.

I sort of remember reading somewhere that in order to fix the cylinder dropping out requires machining of the intake ports going to that dry cylinder. That or possibly a baffle to route some fuel to it. I tried opening up the reed valve area but it made no difference.

Good luck and post back your results.

carl
Aluminum tape sounds good. I should have thought of that. I have a roll of it with sticky back. I don't think I will trust a twin cylinder without any help. Minimally I will put a glow igniter on board if I use glow plug. It is just like flying a twin engine plane. Always better be safe than sorry. At least with an igniter you can always make sure both cylinder lights up. I think it is fine when the engine is running wide open. It gets a bit iffy once I back the throttle down. Especially if I have to do an aborted landing and go again. If one cylinder drop at that time it is pretty critical. I am too lazy to experiment with the intake modification. That will require a complete tear down so I don't get metal all inside the engine. I will just leave mine on CDI for now. The OS 7D carb should work fine for the engine. I have a few of them and I made try one later.
Jan 22, 2020, 12:46 PM
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I put onboard glo on mine. It didn't help at all. As a matter of fact, the last flight cost me a plane.

carl
Jan 22, 2020, 12:58 PM
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Quote:
Originally Posted by carlgrover
I put onboard glo on mine. It didn't help at all. As a matter of fact, the last flight cost me a plane.

carl
Really? When the rear cylinder dropped I put the glow igniter back on the plug and it fired up right away. I can imagine having a dropped cylinder in the air is quite an experience. Especially if you don't have altitude.
Jan 23, 2020, 12:29 PM
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yeah, it was quite an experience. The cylinder dropped out shortly after takeoff. I was flying a Royal 1/5 scale bird dog on pretty much a .50. It stalled like a rock and came in nose down. I scrapped out the whole thing.

carl
Jan 23, 2020, 12:52 PM
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Quote:
Originally Posted by carlgrover
yeah, it was quite an experience. The cylinder dropped out shortly after takeoff. I was flying a Royal 1/5 scale bird dog on pretty much a .50. It stalled like a rock and came in nose down. I scrapped out the whole thing.

carl
Yes, that is the worst time to have a dropped cylinder. Or a dropped engine. Or a dropped electric motor. I once made a double stacked electric motor and one of them went out of sync on take off. Not enough power to keep flying on just one.
Jan 26, 2020, 08:51 PM
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Flew the MVVs 1.44 twin on methanol today. Almost identical performance to the Super Tigre ST3000 running on E85 Ethanol. I got between 7,500 to 7,700 RPM on the ground. Engine unloaded to around 8,500 in the air straight and level. A little less on the climb and the turn and a little more on the dive.

Got raw fuel on the vertical fin when I finish flying so the carb is spitting fuel still. The original Walbro was spitting really bad. The exhaust was a bit too black for my liking. I hope it is either the engine breaking in or something rubbing on the exhaust. I hate to have to tear down the engine to check what is going on inside.

I used the metal carburetor adapter I made, screwed up and repaired.
Jan 26, 2020, 10:39 PM
Still gassin' it.
A velocity stack might help with the spitting….
Jan 26, 2020, 10:50 PM
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Quote:
Originally Posted by 1967Brutus
A velocity stack might help with the spitting….
I have a few velocity stacks for the Walbro carb but not that easy on a Super Tigre carb. Not much lip to mount the stack. Then again I am not sure if the spitting is that intense. The Walbro carb was intense.
Jan 27, 2020, 12:45 AM
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That a nice looking engine and pipes setup, must sound good too. I know you said before that you're hard of hearing but I think you can still hear it.

Who's make the pipes?
Jan 27, 2020, 01:14 AM
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>>That a nice looking engine and pipes setup, must sound good too. I know you said before that you're hard of hearing but I think you can still hear it.<<

I was wearing my hearing aid today just to hear it.

>>Who's make the pipes?<<

MVVs. It came with headers and pipe/muffler. I don't think it is a tuned pipe. Or maybe I need to tune it.
Jan 27, 2020, 09:54 AM
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Bru-line used to make an air filter for glo carbs that had a small rubber boot and a filter with a plastic ring around it. That would make a great venture. I doubt they're around but it shouldn't be too hard to scare one up.

carl
Jan 27, 2020, 12:38 PM
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Quote:
Originally Posted by carlgrover
Bru-line used to make an air filter for glo carbs that had a small rubber boot and a filter with a plastic ring around it. That would make a great venture. I doubt they're around but it shouldn't be too hard to scare one up.

carl
I can make an air filter for the carb. Maybe I will give that a try. Assuming there is enough room on the carburetor top to accept a cinching method.


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