Archive for September, 2012
Running and flying the SV-17cc gasoline RC engine
I accidentally deleted the entire thread by mistake. So I recreated it here again. Sorry.
A while back I had acquired a SV-17cc engine. At the time the reviews weren't all that good for it either. But the price was right, so I couldn't resist.
When I first ran the engine, I found that I couldn't lean it out enough to run at its top speed. It stayed blubbery rich even with the needle valve all the way out, ready to fall out even. So when I looked at the carb I found that it had a Walbro WT-694 carb on it with a 12.7mm venturi bore, which I thought was way too big for a 17cc engine. As I have seen them a carb with around a 9mm venturi is about right. A 12.7mm carb is big enough to run a 35cc engine or even some 50cc engines too. So I rummaged around and found a WT-520 carb with a 9.53mm venturi and I put it on the engine. Now the engine ran great, easy to adjust, throttle response good, nice RPMs and I could lean it out good too.
At that point I didn't see any reason to not use the engine as it was performing good now.
...Continue Reading
A while back I had acquired a SV-17cc engine. At the time the reviews weren't all that good for it either. But the price was right, so I couldn't resist.
When I first ran the engine, I found that I couldn't lean it out enough to run at its top speed. It stayed blubbery rich even with the needle valve all the way out, ready to fall out even. So when I looked at the carb I found that it had a Walbro WT-694 carb on it with a 12.7mm venturi bore, which I thought was way too big for a 17cc engine. As I have seen them a carb with around a 9mm venturi is about right. A 12.7mm carb is big enough to run a 35cc engine or even some 50cc engines too. So I rummaged around and found a WT-520 carb with a 9.53mm venturi and I put it on the engine. Now the engine ran great, easy to adjust, throttle response good, nice RPMs and I could lean it out good too.
At that point I didn't see any reason to not use the engine as it was performing good now.
...Continue Reading
Flight testing the NGH 9cc gas engine
I had put my second NGH 9cc engine in a Great Planes Escapade 40 size plane.
The only modification done to the engine was to use 8x32 fittings for the crankcase to fuel pump diaphragm and 1/8 inch Tygon fuel tubing instead of the smaller 3/32 inch fuel tubing. Previously I showed a video clip of how well the engine ran like that so I was motivated to fly the engine to be sure it was working in the air too.
Also the carb should have the low speed needle set to about 6 turns out and the high speed needle set to about 1 and a half turns out. The LSN setting on my case was about right and I didn't need to change it from 6 turns out. Also the carb does spit fuel out, so it is not running too rich, it is just the nature of the beast, so to speak.
...Continue Reading
The only modification done to the engine was to use 8x32 fittings for the crankcase to fuel pump diaphragm and 1/8 inch Tygon fuel tubing instead of the smaller 3/32 inch fuel tubing. Previously I showed a video clip of how well the engine ran like that so I was motivated to fly the engine to be sure it was working in the air too.
Also the carb should have the low speed needle set to about 6 turns out and the high speed needle set to about 1 and a half turns out. The LSN setting on my case was about right and I didn't need to change it from 6 turns out. Also the carb does spit fuel out, so it is not running too rich, it is just the nature of the beast, so to speak.
...Continue Reading
