Carburetor fuel fittings
- Thread starter Larry Trotter
- Start date
I haven't run them but from reading threads on here and other forums this is what I've put together to try... The Rj4 has a pulse that needs to go to the intake or transfer port and is the bigger of 2 that they recommend for a modified or large bore and the 272 only require a fuel line and recommend for the stock 66/80... Cafe motor racer has the adapter kit to fit a 32mm intake... So it's going to need some mods to fit a 40mm jug... Sorry I don't have the experience running them but this is where I'm at with the saw carbs... You can make a plate to go to a G2 reed and I have some of those to try also
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Thank everyone for their knowledge and responses, it’s a great help to me. This is a little off topic because this isn’t running on a bicycle but is a 47cc2 stroke that’s intended for scooters I think mainly. I am going to run one of these on a fairly large drone. The main issue is the stock float type carburetor suffers from foaming in the float bowl and fuel line during sustained full throttle operation due to the high vibrations which makes the output power unstable. I am thinking that this will be a very simple inexpensive solution to the problem. People here seem to have a much better understanding of little 2 cycle engines than anywhere else I have found. I will let you know my results. Thank you.
Larry
Larry
Frothy oil... Got me thinking about an incompatible mix up... If you're using methanol or alcohol there's something that you need to add or use an oil made for that fuel ? I've had an oil injection do that with 2 different oils before when I put a synthetic in with a little conventional oil left in it... Like stabilizer or it could be from oil that sat around and settled some... So the additives aren't completely mixed and aggravated by the vibration
Yes, I first tried the filter at the top of the line but had foaming issues then at the bottom which was better but still started surging after about 4 or 5 minutes at WOT. Just as an observation, it used about one ounce of fuel per minute.
A bigger longer line and filter bigger tank farther away... Eventually you'll get there if it's getting better... I would try a 3/8 line and filter like you have then adapter down to whatever size the carb is...
Or there's this but for the money I would make something... Under pressure might make the difference... And the return would help keep it in the tank until it can calm down? I'm just throwing ideas at it... How big a plane is this thing?
Or there's this but for the money I would make something... Under pressure might make the difference... And the return would help keep it in the tank until it can calm down? I'm just throwing ideas at it... How big a plane is this thing?
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I think your thoughts about a larger diameter fuel line may be a solution. Now air seems to be trapped in the line after the fuel valve at the bottom of the tank. I will see if the different carburetor type works along with the larger fuel line.
The plane is a Rogallo wing with about a 7 foot span.
The plane is a Rogallo wing with about a 7 foot span.
For a little knowledge to the group, the non-float carburetor solved the foaming in the float bowl problems and then some. The engine starts much easier with it and it would solve fuel tank placement problems for any odd build that would have a tank lower than the engine. As you can see the carb is actually mounted upside down but still performs perfectly. Seems to feed plenty of fuel as lots is returning to the tank in the return line. Adapting one to a China girl should be nice. One issue is that there’s a port on the carb that needs to go into the intake manifold for some reason. Only mods to the scooter motor is replacing the sprocket shaft with a M10 1.5 grade 12 bolt for the prop shaft and running the engine upside down.
And for anyone curious about the power these little scooter/bike motors actually make, this is the horsepower calculation at a measured 7,500 RPM. The specs say they make about 1.5 horsepower but it nearer 3.7.
Well it ain't a engine powered bicycle. But you posted here, so whatcha got? RC Paraglider? Curious minds need to know.
I flew a Ultralight until some SOB stole it in 1983.
Tom
I flew a Ultralight until some SOB stole it in 1983.
Tom
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