Need help where to look

VMAX  Forum

Help Support VMAX Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

longride

Member
Joined
Dec 21, 2013
Messages
24
Reaction score
0
Location
Daytona Beach
Well, my VMax has been running bad and I did a COP conversion and just cleaned and sealed the tank, and took down the carbs for a complete cleaning and servicing. The whole fuel system is spotless but it is doing the same thing pretty much every ride for a while now.

It starts out great and runs beautifully like it did today. Then when it warms up real good it runs like crap. Spitting and backfiring and seemingly not firing on all cylinders. It barely will idle and I get the gas smell, but I KNOW the cabs aren't clogged or dirty, They were just cleaned spotless. It always starts and runs perfectly when cold. Battery was tested and is good. Not sure where to look. I'm sure someone can point me in the right direction. Thanks!
 
Running rich. You may have your float levels too high. The bike gets richer as it warms up. That's why you're getting the gas smell. Pull the plugs and post some pics. I bet it starts right up without the choke, too, right?
 
Either rich as Dave pointed out or bad electrical component. Test the pickup coil when cold and see what you get for ohm loads and when hot and it's missing. I would also try swapping the CDI box and seeing if that clears it up. I can always loan the parts needed for testing.
 
Bam, Sean hit all the culprits I was to suggest. I had a similar problem where I'd get a mile or two away from home and it would start to sputter and then die. No start when warm but come back when cold, vroom vroom!
Needed new pick up unit. It was the last thing I checked! A lot of work to just learn more about the wonderful Vmax.
 
The float levels were rich when I took it apart. I set them lower than before and by the book, and all the same. Bike runs OUTSTANDING when cold. Perfect. I don't think it can richen up THAT much when warm. It does need choke to start and run, and hot restarts aren't good. I have a feeling it is electrical because it isn't running rich, it's running BAD! Just pulled the plugs and the right rear is perfect, right front looks good but slightly rich, left rear was slightly fouled, and the left front was gas fouled badly. Since all float levels and adjustments are equal, the plugs should be equal, but aren't. I think pickup coil test and maybe CDI box going. Thanks for the advice.
 

Latest posts

Back
Top