At Fixya.com, our trusted experts are meticulously vetted and possess extensive experience in their respective fields. Backed by a community of knowledgeable professionals, our platform ensures that the solutions provided are thoroughly researched and validated.
2003 honda 750 ace. i just bought it and it runs great at level speed, but rough on acceleration.. also lots of backfire on deceleration. any help is appreciated. thanks
- If you need clarification, ask it in the comment box above.
- Better answers use proper spelling and grammar.
- Provide details, support with references or personal experience.
Tell us some more! Your answer needs to include more details to help people.You can't post answers that contain an email address.Please enter a valid email address.The email address entered is already associated to an account.Login to postPlease use English characters only.
Tip: The max point reward for answering a question is 15.
Sounds like you need to have the carb jets cleaned. You can try seafoam that you add to fuel tank and ride it to see if that will clear it up, but I have had the same problem with my VF750C Honda Magna with only 8000miles and mine turns out to be fine tuning the injectors. This is only after the carbs have been reworked and cleaned.
The most common reason for backfiring is lack of back pressure from changing the exhaust. To compensate for the flat spot you get you put in a jet kit. This leaves the possibility of more unburned gas getting into the exhaust. Honda uses Kei Hin carbs with a fuel shut off diaphragm to help limit this condition (backfiring) by turning off the fuel to the carbs during deceleration. Even stock exhaust can pop or backfire. Typically it is caused by air getting into the exhaust either past the copper o-ring gaskets in the head or leaking muffler connections from the head pipes to the mufflers. Try replacing all the exhaust gaskets and you should minimize this condition.
Two things can cause popping or backfiring on deceleration. The most common is air leaking into the exhaust through the exhaust pipe copper o-ring gaskets. This typically happens when the exhaust is replaced without removing the old ones (doubled up) or simply reusing the old gaskets and they don't seal. The other thing that can cause popping is bad air cut diaphragms on the carburetors. If they are old and sticky or have holes in them they don't properly shut off the gas on deceleration causing the backfire.
Probably the idle jets are set too lean. From what I have read, the factory settings are often wrong. Drill out the plugs and adjust. If you use the right size drill you can get in with a small screwdriver and make the adjustments without totally removing the plug. This eliminates the possibility of losing the adjustment screw, which can happen if the plugs are not there.
Best thing to do is put in a Cobra stage 1 jet kit. You will be amazed at how much better the bike runs.
The gas has varnished and turned to ****. You need to take it to a shop and have the carbs cleaned. Next time you decide to store the bike put fuel stabilizer in the tank and run the bike untill the stabilizer gets into the carbs. When you want to store it, turn the gas off and let the bike run all the remaining gas in the carbs out. That is your best bet. Chaz Moto DC
×