VMAX fuel milage


I wouldnt touch your fuel pump or oil pump, fuel pumps on these things arent known for going and a bad fuel pump wont start pumping more fuel in. If it was just your oil that was out of whack then I would rebuild the oil pump, but being both I think something else is your issue. Did you check throttle cables on the sled for adjustment?? Also you can replace the choke assembly, the Yamaha part is discontinued, but its just a standard Mikuni choke setup, you can get a universal one pretty much anywhere (may have to move the location of choke but cheaper than a new sled)

I have the exact same sled and check carbs/cables etc... every year and it gets normally 9-12 MPG (9mpg when Im riding hard in the hills or doing lake runs) As for oil usage, for one tank of gas I use less than a liter of oil.

Another thing that could cause this is if they screwed up the float adjustment when they rebuilt the carbs, which would explain the hydrolocking and also why its still sucking back fuel even after a jet change. This is probably the most likely cause, Id bring it to someone from this forum or another dealer.

Pull your plugs, if they are wet and dark, Id bet your floats arent shutting your fuel supply off.
 
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Your usage of oil should be around 1 quart to 1 gas tank so considering the fuel mileage your not that far off. Once you find the gas problem the oil problem will most likely fix itself.
 
Would this go the same for my 95 vmax 600???
Had a friend clean carbs but he is a cat man. It's there a way to check the float settings?
 
A bad fuel pump can cause high fuel consumption and also hydro lock. A ruptured diaphragm allows fuel to run into the crankcase through the pulse hose. It would normally idle poorly on one cylinder. A quick check is to squeeze the pulse hose shut with a pliers and see if the idle improves, it might take a minute or two.

The float height should have been checked after the needles and seats were replaced as that will change. I hope it was the needle and seats they replaced and not the needle jets and jet needles ("they installed new jets and needles"), if they did that they did the wrong thing. What were the part numbers of the replaced parts?

Check the choke adjustment. The cable should have a small amount of free travel at the carb.
 
Econow said:
Would this go the same for my 95 vmax 600???
Had a friend clean carbs but he is a cat man. It's there a way to check the float settings?
Click to expand...

Yes.
It should not have changed though because of the cleaning - unless the needles were switched between the carbs and even then, not real likely to be the problem, but the adjustment should be checked.
 
Something not mentioned is it will require more throttle - hence more fuel and oil usage - if something isn't rolling freely in the drivetrain. Lift the back and see if you can turn the track by hand. If not, you should be able to easily turn it by turning the secondary. If that's hard, you need to look at track tension, slide wear, wheel bearings, jackshaft and drive axle bearings. Also checking ski alignment can help. Any extra drag anywhere will suck more fuel and oil.
 
New boyeson reeds, clean carbs, rebuilt primary, and new bearings for all the wheels, and my 97 600 still can't top ten mpg. 9.7 is what I averaged this season.
 
The Vmax 500's are know for being oil ad gas eaters! 40-50 miles on a tank is normal for those sleds. however some off the line were fine and had good mileage but for the most part they are know for eating gas and oil.
 
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