Honda Express with Replacement Carburetor Video – Carb was installed on a 1981 Honda Express that originally had an auto-choke mechanism. I removed the auto-choke hoses and just need to plug the port at the bottom of the intake.
Honda Express Replacement Carburetor Installation Video – Here’s the installation video taking you through the installation process. This carb went on a 1980 Honda Express with manual choke.
Honda Express Carburetor Troubleshooting Video – Number 1 issue that you need to address is install a new fuel filter when you install the carb. If dirt, rust, crud, foreign materials get in carb through your 40 year old fuel system, you will experience leaks with the carburetor. YOU HAVE BEEN WARNED. Don’t complain to me about a leaky carburetor.
If you have trouble with four-stroking (running rich) after installing the carburetor, then try the following:
- adjust needle jet to a slightly leaner position by moving the clip up a notch at a time. The carburetor comes with the needle jet set at the middle setting;
- you might be able to order a smaller keihin main jet from jetsrus.com. The current main jet is about a 50 which I believe corresponds to a 0.5mm jet.
- You can run a more free flowing air filter like a pod filter with a 28 mm inner diameter to fit this carburetor; use panty hose or similar material as an air filter, or you can run without any air filter at all to introduce more air into the engine;
- You can run a hotter spark plug like an NGK-BP4HS;
- You can pull out the emulsion tube from under the main jet and drill out the bottom holes to a larger size;
- You can drip solder into the main jet and use micro drill bits to drill the main jet to any size you want;
- If you are running premix, you can uncap the oil injection port on the carburetor to let more air in;
- You could find a velocity stack air filter to introduce more air into the system;
- A combination of the above.
I’ve had the best luck just running without any air filter at all.
If your carburetor is leaking fuel then dirt or rust or some other foreign object from your fuel tank is probably preventing the float needle from sealing the needle seat in the carburetor. You should install a new fuel filter to help prevent this from happening. To stop the fuel from leaking, you simply have to take the float bowl off the carburetor; remove the float; and then spray out the seat and perhaps the float bowl and the rest of the inside of the carburetor with carburetor cleaner. Once the debris is removed from the seat, the float should seat properly and stop the flow of gas once the bowl is full.