poor gas miliage 95 vmax 500

crfbikerboy

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Jan 4, 2010
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Whats the best way to lean out these engines without blowing them up..... My 95 vmax 500 has black plugs almost all the time ... Even in very cold weather. I'm getting about 120-150 km's out of a full tank 35L I think. Should I drop the needle one or two positions or smaller main jet...or ????? I need to get a little better than this so I can reach the next gas station...holy crap its hard on gas. Running fairly well , but can feel its a little rich when running a steady speed,, it almost wants to slow down or it actually does slow down .

Ps. I'm fairly sure this sled is bone stock, comes from up north were its very cold. Probably ran great up there.
 
yes they were rich from factory but you need to be carefully you guy's see some pretty cold temps up there.

you need to find out whats in there now not a guess and go from there,yea dropping the needles a notch and maybe mains,but you'll need to monitor plug color close.

clutching has a part in this also don't forget that if your over revving and have inefficient clutching you'll suck fuel too.
 
thinking your fuel mpg might be nature of the beast, jus got back from weekend trip with some buddies, one rides a 600 vmax, he would use a full tank to my third of a tank, couldnt believe how hard on gas that thing is
 
Check the reeds and clutches as well. Any extra driveline drag introduced by wearing clutches will decrease mileage. The 600 pogos were absolute pigs on gas and oil compared to the tripples. Not sure if that applies ot he 500's as well.
 
dhoward said:
thinking your fuel mpg might be nature of the beast, jus got back from weekend trip with some buddies, one rides a 600 vmax, he would use a full tank to my third of a tank, couldnt believe how hard on gas that thing is
Not necessarily,,


everyone bashes twins but my last trip up north last year i got 12-13 with my 98 600,but it's stock and was tuned in and clutched right,they can do it but it takes effort to get em set up right.
 
thanks guys, I might try to drop my needles 1 notch, and maybe the main 1 size. I'll do each mod at a time and monitor it. I was also thinking the secondary clutch is a little tight. Not sure, but just maintain 45 to 50 miles per hour , I'm reving aroound 7600 or a little more. Full throttle after that will bring it to 75 -80 miles reving around 8100. Is this normal, or should I be able to cruise about 50 miles per hour at a lower rpm??? I just rebuilt the primary clutch and it seems to work great. I can't see any milaqge gain at all if I'm reving over 7500 rpm . Its not working very hard to maintain 50.....help
 
oh, i forgot to ask....how long the reed valves last in these motors...??? Its got 16000km's on it ....with a fresh to end a couple of years ago. It doesn't look like the reeds have ever been touched (bolts pretty corroded). Maybe thats some of my gas milage troubles.
 
reeds last awile sure but they need to be checked,stick with OEM if you need to replace.

at WOT you dont want anymore then 7800ish.
 
With my rebuilt clutch I'm over that a tadd. What kind of rpm are you running at 50 miles per hour????? I'd like to dial it in with a known rpm at crusing speed. Thanks for the help
 
I dont recall,sorry,how much is a tad? that doesnt really matter as long as your in the rpm range.

whats engagement speed?
 
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on my 96 600 cruising 50mph is around 6000 6500 rpms. what are you jetted at and what temp is the coldest you run in?
 
just for info i set and was running fat on oil and fat on needle and fat on main, adjusted oil dead on, no mpg gain, adjusted needle one washer leaner, no mpg change,adjusted main have not had a chance to see if it did anything i get 10 mpg average speed on 100 mile trip 34.3 mph according to gps and max speed of 91.5, my opinion is if you want better mileage you would have to gear up and work on secondary shift but then it wont be as quick on short squirts
 
One of the three 94-95 500's that we had got horrible mileage. Tried everything but never got it over about 7mpg. It ran great but always guzzled compared to the other two. Both the others averaged between 9 and 12 mpg. Plugs were always a little black in my 95 but it always ran awesome and never fouled plugs.
 


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