VMAX fuel milage

1

1rspr

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Jan 4, 2010
Messages
6
Age
81
Location
MN
I have 2 VMAX 500's. A 1997 and 1998. With my grand kids riding them this weekend. The 1998 used 1/2 as much gas and oil as the 1997. Younger lighter kid on the 1997. Carbs were gone through last spring. Can't figure why the big difference.
 

Did they both have the same mileage? If so, ride the sleds. If there is that much difference you should notice a difference in how they run. One cylinder dead on one of them?
 
They both have close to 2000 miles on them. The one that uses the most fuel runs the best. Some say the chokes may be leaking by on the plunger. And that is the one carb part that can't be bought. Obsolete!. Since they seem to run almost the same I wouldn't think the clutching would be a factor. My problem here in northern Minnesota is it can be a long ways between gas stops. It ran almost dry on a 53 mile loop.
 
It was not using as much fuel last year. Took it to dealer to do carbs after a week went to start it and the engine was hydro locked with gas. Took it back they corrected that but hurt the mileage by about 25%. I have gotten my hands on another carb rack so I may try putting that on.
 
poor vmax fuel gas mileage

We have a '98 VMax 600 XTC Deluxe. And it never got great gas mileage (8 to 10 MPG), but we took to the shop a few weeks ago to get a pre-season service and carb cleaning. And now it gets like 5 MPG!!! And it was ridden very slowly.

Did the shop screw something up when cleaning the carburetors? Is the idle too high? Are the needles in the wrong position? Float height set too high? HELP!
 
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I have seen One friends carbs cleaned by his dealer and they were a crusty mess when I recleaned them. Another friend went to a local shop and sled wouldn't go over 23mph. They gave it back with a broken cable. I'm not saying all shops/dealers do a bad job, but..... Maybe they tune them super rich because bad mileage is better than fried piston. Both these guys paid like $250. That's frustrating. Learning to clean carbs is the best skill you can learn for snowmobile maintenance.
 
Trail Ryder said:
We have a '98 VMax 600 XTC Deluxe. And it never got great gas mileage (8 to 10 MPG), but we took to the shop a few weeks ago to get a pre-season service and carb cleaning. And now it gets like 5 MPG!!! And it was ridden very slowly.

Did the shop screw something up when cleaning the carburetors? Is the idle too high? Are the needles in the wrong position? Float height set too high? HELP!
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Take it back- It could be caused by several things. The idle too high would not do it - and the idle should have been set to specs, if it is too high let them know. They should not have removed the needle clips in a cleaning. An inlet valve seat could have been damaged when it was "cleaned" and is now leaking.
 
Well we took it back and they installed new jets and needles ... now it gets 4 MPG when driven by Grandpa!!! Argh!!! We are starting to hate this sled.
 
That's really bad. My 97 600 twin venture at worst got 8mpg at the end of last year, but it had reeds that were cracking, and needed wear parts on the primary replaced. It's back to 10 mpg now and even more power than its ever had since we have owned it. The wife will be telling me to show down a lot when she gets on the back after we get back from Puerto Vallarta.

Have you ever Checked the reeds?
 
Good suggestion on the reeds.

I talked to my Dad tonight and it is drinking lots of oil too (like a quart every 40 miles), so we are thinking it may be the fuel pump. We are going to replace or rebuild the fuel pump next.

Unrelated, but my ETEC is getting over 20 MPG and using less than a quart of oil every 200 miles. Technology has come a long way in the last few years.
 
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Oil too? Then it needs a new oil pump. Yamaha had lots of issues with these on the twins the first couple years of the pro action. There is a revised part number for the oil pump. I had to replace mine as it DRANK oil. Is decent on oil now.
 
It used to get 8 to 10 MPG and it was not too bad on oil.

But now it guzzles both gas and oil, so we are thinking it is the fuel pump.

The sled only has like 3,400 miles on it.
 
Trail Ryder said:
It used to get 8 to 10 MPG and it was not too bad on oil.

But now it guzzles both gas and oil, so we are thinking it is the fuel pump.

The sled only has like 3,400 miles on it.
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I can't see how a fuel pump would cause a fuel economy issue. It's job is to deliver fuel. The carb does all the metering.

It's like blaming the pizza delivery guy for obesity.
 
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