RCGF 20cc : beam mount vs rear mount
#1
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RCGF 20cc : beam mount vs rear mount
I noticed there is now a version three on the rear mount 20cc.
My main question is why are there different carbs on these same size engines from the same manufacture
Which is better for reliability ?
Thanks
My main question is why are there different carbs on these same size engines from the same manufacture
Which is better for reliability ?
Thanks
#2
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RE: RCGF 20cc : beam mount vs rear mount
The carb was a weak point on my rcgf 20cc. It took a lot of work to finally figure out the pop-off adjustment wasnt done properly where ever it was built. I finally got it right and the engine ran better than it ever did out of the box. Mine is a chinese walbro copy. I'm only speculating that they might be trying to find a good carb. Mechanically, I think the engine is ok. Just a problem with my carb.
Edwin
edit - Havent bought another rcgf yet. But will probably go with a DLE 20 next time. The only thing I like about the rcgf is the slanted spark plug mount.
Edwin
edit - Havent bought another rcgf yet. But will probably go with a DLE 20 next time. The only thing I like about the rcgf is the slanted spark plug mount.
#4
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RE: RCGF 20cc : beam mount vs rear mount
There is a diaphram that pushes on what looks like a float valve needle (similar to whats in auto carbs on the float vavle). There is a little fork that the diaphram pushes on raising and lowering the needle and is held closed with a little spring. This regulates the fuel flow. The fork must be tweeked so that it doesnt allow too much or too little fuel flow. Mine was starving the engine. I pulled the plug and it was pretty much dry, not getting enough mixture. What I dont understand in my case, is why it worked for about a gallon, then the engine starting loosing power to the point it would die at about mid throttle. Eventually it wouldnt run at all. After a warrenty trip and returned with the same problem I worked on it myself. Without the right tools its a trial and error process. It took about five tries at tweeking (bending a little tab) the fork to get it right. If you go too far in the tweeking, it floods the engine. Which is what I did on the fourth try, so I went back a tad and all was good. It ran better than it ever did. When the chinese copied the walbro carb, what they didnt realize was that the little spring under that fork appears to be calibrated. Other guys with the same problem were able to fix it by just replacing the spring with a real walbro spring. Most others just replaced the carb.
Edwin
Edwin
#6
Beam mount flexibility
Is it ok if my beam mount (white one) has some flex in it when applying movement down or up with the hand on the shaft of the RCG 20cc? I mean that the engine is not rigid mounted on this mount but it moves by hand 1-2mm. Is that ok or it induces vibration to the plane? It works good thought.
#9
Here's "THE" engine mount for 20cc beam mount gassers, such as the DLE 20 or 20RA.
http://www.horizonhobby.com/products/HAN2033
These will result in a cooler running engine,since the side plates, or webbing adds a considerable amount of cooling area. I have tended to have problems in the past with .90 class 4 stroke glow engines making the composite mounts soft, especially on a H9 Showtime 50 with OS .81A mounted inverted. Switched out the composite mounts for the slightly shorter version of these, and the engine was noticeably cooler after landing. With the stock composite mounts the engine mounting was actually spongy after a flight, with the aluminum, not so much!
I also have a pair of these for the DLE 20RA I have on an AeroWorks .120 size Yak 54 and the engine tends to run really cool. If you check the temperature of the mounts side plate or webbing, they feel as hot as the CC or cylinder head, since it's sinking a fair amount of heat from the engine.
FWIW, after torquing up the engine bolts through the slots during installation, I've never had one loosen, even after more than a full season of flying.
Pete
http://www.horizonhobby.com/products/HAN2033
These will result in a cooler running engine,since the side plates, or webbing adds a considerable amount of cooling area. I have tended to have problems in the past with .90 class 4 stroke glow engines making the composite mounts soft, especially on a H9 Showtime 50 with OS .81A mounted inverted. Switched out the composite mounts for the slightly shorter version of these, and the engine was noticeably cooler after landing. With the stock composite mounts the engine mounting was actually spongy after a flight, with the aluminum, not so much!
I also have a pair of these for the DLE 20RA I have on an AeroWorks .120 size Yak 54 and the engine tends to run really cool. If you check the temperature of the mounts side plate or webbing, they feel as hot as the CC or cylinder head, since it's sinking a fair amount of heat from the engine.
FWIW, after torquing up the engine bolts through the slots during installation, I've never had one loosen, even after more than a full season of flying.
Pete
#10
My Feedback: (2)
Have a DLE 20 on what is now a fairly high time install on a set of composite mounts. Moved from one plane to the next as the first became unrepairable (after several "incidents) as they still appeared in good shape. 2nd plane is now 2 seasons old, making this mount maybe 4 seasons old total. HUNDREDS of hard flights without issue in a very aerobatic plane (70" Great Planes Revolver).
Bottom line, no issue with the composite mounts in my experience.
Bottom line, no issue with the composite mounts in my experience.
#12
Uau! How did that happen? On the ground or in the air? Did you hit the ground with the prop? Did it show signs of cracks or it just happen? I think I have this black beam mount somewhere, it seems more rigid than the white nylon one that I'm using now..
#13
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Not sure how many flights I'd made but upon landing I noticed a strange rattling sound while taxiing back. Once it got close I could tell the prop was not in the proper orientation so I shut her down and removed the cowl only to discover what you see here. I have no idea how the cowl could keep it together like it did but it must have snapped on landing and it stayed close enough to center to allow me to taxi back to the pit successfully. I went to the Hangar nine metal mount mentioned earlier.