My 1999 VF750-C fires right up but dies after I ride a very short distance. It's hard to re-start, but once running it performs, OK, idles at lights, etc.
Any insights?
I would check the auto fuel shut off diaphragm, make sure the vacuum line is connected etc. Then I would go to the tank petcock, clean the screen etc.
Check battery is tight with wrench not a screwdriver.
Can it run with the gas tank open? Could be tank breather clogged? It sounds like the bike has enough fuel at start-up but runs leaner and leaner as you drive it until it dies.
My husband changed the vacuum tubes and put in some gas additive Sunday and it started fine for a test ride. But yesterday I had trouble starting it as I was leaving for work and coming home but not as bad. He ordered a diaphragm for the petcock and will rebuild it as soon as the part comes in. I had some trouble a month ago with gas leaking through the petcock and I now turn it off when the bike is parked. I try opening the gas tank when I start it, but it doesn't seen to have much effect. Thanks for any suggestions, we will just keep trying until we find the problems.
Has the bike sat for a period of time without starting? IF so the slow speed jets are clogged. If you can start it with the choke on, then turn choke off and it is very hesitant to accept throttle its more than likely slow speed jets.
If it dies for no reason while riding as if it runs out of gas, then its more than likely the auto fuel shutoff diaphragm.
Quote from: Greg Cothern on June 12, 2012, 08:59:58 AM
Has the bike sat for a period of time without starting? IF so the slow speed jets are clogged. If you can start it with the choke on, then turn choke off and it is very hesitant to accept throttle its more than likely slow speed jets.
If it dies for no reason while riding as if it runs out of gas, then its more than likely the auto fuel shutoff diaphragm.
I seem to remember the auto fuel shutoff diaphragm is very expensive, but there was an affordable rebuild kit. Do you remember or know where to get the rebuild kit? Or am I imagining this...
The rebuild kit (Petcock Cover Set) is very inexpensive (<$35). It's part # 29 in the diagram shown here:
http://www.ronayers.com/Fiche/TypeID/26/Type/FUEL_TANK/MakeID/1/Make/Honda/YearID/40/Year/1999/ModelID/6593/Model/VF750C/GroupID/277810/Group/FUEL_TANK (http://www.ronayers.com/Fiche/TypeID/26/Type/FUEL_TANK/MakeID/1/Make/Honda/YearID/40/Year/1999/ModelID/6593/Model/VF750C/GroupID/277810/Group/FUEL_TANK)
The problem is that it's not listed in the parts fiche for all years of the 3rd gen Magna. For the earlier years, there's only the complete vacuum petcock which runs more than $100. There's no reason to buy that though since you get all that's likely to wear with the cover set shown above and it will work for all 3rd gen's despite the fact that it may not be listed under your year.
When looking up a part for a 94 I will look at other years to see if they have other options.
Some times the person at the desk will say it may not be the same but it is.
There are only 1 or 2 thing that are not the same on all 3rd gen Magnas.
To test if it is the petcock, bypass it. Fuel should not overflow the carbs if the floats are properly functioning. It does not take long of a bike sitting to have gunked up carbs. All the jets are very small and get plugged up very easy.
The bike rarely sits for more than two days in a row. I have a 50 mile round trip to work 5 days a week. The bike has been starting a little easier but after it idles for a minute, when I give it gas it dies. But once I get it going I have no more problems until I start it again at the end of the day. It has been getting me to work and back so far.
I finally got a day off and stayed at home long enough for my husband to work on my bike. He had ordered the auto fuel shutoff diaphragm rebuild kit and got it in. I have been riding to work the last few days with no problems at all.
Thanks for all the help.
Great news!
Indeed! Glad to hear that it was something simple and relatively easy to deal with.
Ride Safe!!