My fuel pump went out on my old three wheeler. Anyone out there know where I can get an electric fuel pump that works on small engines? I tried the lowest pressure fuel pump I could find(3 to 5 PSI) and then followed it with an adjustable regulator(1 to 4) and the pressure is still too high.

 

What kind of fuel pump did your three-wheeler have originally? Was it an actual pump, because the tank is lower than the carb, or is it a diaphragm valve that won't let the fuel flow unless it is getting vauum pulses from the engine? Is the tank higher or lower than the carb? The problem is usually that the elec. pump, even with a regulator, puts out too much pressure for a needle and seat designed for gravity flow and the needle/seat can't shut off the fuel flow. Is this the problem you are having? The float bowl just fills up and floods out the vents? What carb do you have? If it is the big Mikuni 36mm then you can get a needle/seat designed for snowmobiles that use a fuel pump and will stop that problem. Might be easier to just try to get the original-type pump. If it is no longer available from the dealer, and they don't offer a rebuild kit for it, try a cycle salvage. -TD

 

Perfect assessment. It's the one with the vacuum diaphragm. The carb is a Keihen. I really want the quick starting of an electric fuel pump. The carb just floods the engine when I try to start. The fuel tank is mostly below the carb. I was thinking about adding an extra tank to buffer the pump pulses.

 

Keihen carb, so what you have is an old Honda. I don't know if there is any needle/seat available for that that would solve your problem. Do you mean like a small tank mounted above the carb, pump the fuel from the main tank to the aux. tank and let it gravity flow to the carb? That might work, but you'd need to be able to switch the pump on and off or have a float valve arrangement to shut it off to keep the aux. tank from overflowing. If you used a sealed tank, when it filled up and pressurized from the fuel pump, you'd just have the same problem. Sounds like this could get complicated in a hurry. So with the stock arrangement, if it sits for a few days with this crappy and expensive excuse for gasoline that we have now, it just evaporates out of the carp and you're left cranking and cranking on the thing just to refill the float bowl and get the engine started? Maybe you could run the elec. pump as an aux. pump just to fill the float bowl, to prime it and then turn it off before it floods and run it with the stock diaphragm pump. -TD

 

It's a Kawasucki. I was thinking about two things. A small aux tank with a float ( will need some thought) above the carb. I was also thinking that a small tank with air trapped in it might buffer the pulses of the pump. I'm not convinced that the pressure is too high from the pump. It could be that the pulses are pushing the needle open. Hydraulic pressure from the pulse could be very high. Thanks for your input. You are so right about the evaporation issues. I have been thru a starter already.

 

Kawi...wow, I'm really out of it. I thought that Honda was the only one that used the Keihin carb. Been away from it too long, I guess. Just when you think you know everything...! Well, it's worth a try. I guess at this point you're thinking anything is! Let me know how it goes. -TD

 

TigerDan
I think I solved the problem. I still need to try it. If I pump the fuel with the electric pump from the fuel tank up above the carb and then hose it back into the tank the pressure on the line will be low. Then, up above the carb put a tee in the line and let the fuel gravity feed into the carb. The line to the carb will always be full but not pressured. Cool ah.

 

Sounds good. Hope it works out for ya!

 

If I were you, Id just use a can of starting fluid to start it
How come your carb leaks out the gas, or it evaporates?
My Yamaha, My moms Kawasaki's, and my buddiues Suzuki all will start within 10 seconds of cranking. and thats if they've sat for 6 months
My buddies Suzuki had a bad needle/seat and it would flood if he didnt turn the gas off, but other than that, we havent had any evaporation problems?
Maybe rebuilding the carb would help?

 

Andy, I think you get better gas back there than the crap we get out here in the west. I don't know for sure about up in Washington state, but here in Ca. it's so loaded with additives, like that MTBE junk, that you just breathe on it and it evaporates, but not before it eats half the rubber in your fuel system!

 

Hrm, that sucks you guys got crappy gas...
Glad i live in AR... less rust, better gas, and more space to breathe