1981 Honda Express 11 na50 carburetor

Ok, here's my situation. When I got the bike the carburetor was leaking gas from the air intake. I was told to clean it and replace the float pin. while taking it apart I realized that the oil line was connected to the port with the float needle in it and gas to the other port. When the bowl would fill up the float would push the pin up shutting off the oil flow but not the gas. Thus, overflowing the carb with gas. So I switched them. It stopped leaking gas but when I tried to start it, it spit oil out of the exhaust. Finaly, I decided to exclude the oil injection all together, capped the oil line, premixed my own gas, and ran it into the port with the float pin and left the other one open. It runs like a dream, started on the second kick!

Which brings me to my question(s).

Will this damage the bike?

Do I still need to put oil in the oil tank for the motor?

Is there anything else that I need to do besides cap the oil line where it met the carb?

If this is safe, what is the best ratio for mixing gas for these things?

Greatly appreciate anyone who can help and sorry for the long post, I'm a moped army virgin.



Re: 1981 Honda Express 11 na50 carburetor

That would be a very bad idea. The oil pump supplies oil directly to some of the bearings. Supplying it through the carburetor will get some oil to the right places, but probably not in the right quantities. Plus it will be diluted with gasoline. I also suspect that the carburetor is not designed to handle oil.

Hook up the plumbing correctly, clean out the exhaust, run the engine, and clean the exhaust again. You should be good to go.

Re: 1981 Honda Express 11 na50 carburetor

you can run these on premix fine. i didnt read the whole post but running premix through the carb wont mess it up.

Re: 1981 Honda Express 11 na50 carburetor

ReidMcT - Wrong! The only thing right about what you posted was "clean out the exhaust".

Sounds like the hoses were wrong; pre-mix is fine, if not better, if you don't mind mixing just leave it the way it is. If you do decide to keep running pre-mix i recommend removing the drive shaft for the oil pump; it's easy, loosen the clamp around the pump, lift pump out, remove drive shaft, reinstall pump, tighten clamp. Make sure you block off all the old opening for the oil system.

No more oil needed in the tank.

50:1 Synthetic, 40:1 conventional.

Run a BP4HS plug.

Re: 1981 Honda Express 11 na50 carburetor

Thanks for the responses, this web site has been a godsend! So when I remove that drive shaft it will disengage the oil pump all together? Would it be ok to then drain the oil from the oil tank considering it leaks around the cap? Is there anything else I need to keep in mind? Thanks again for all the help!


« Go to Topics — end of thread

Want to post in this forum? We'd love to have you join the discussion, but first:

Login or Create Account