02 660 Grizzly Vaporlock problem
#3
#4
After riding 10 to 15 miles we stop on trail and chat for 10 to 15
minutes, after starting engine and under acceleration the engine lacks
power and tries to shut down until it is run for a few minutes. Only
happens on warm days. I relate the problem as I experienced on automobiles
years ago when the engine used a carburetor and when fuel pressure was
low and the heat from engine caused the fuel to vaporize in the lines. The
cure for that was to reroute fuel lines and make sure there was ample fuel
pressure and volume of fuel to carburetor.
When the engine on my quad is shut down for that period of time you can
actually hear the fuel bubbling and there is excessive pressure and
vapors coming from fuel tank vent hose. This problem never happens if you are running down the trail at any speed, only after it has been shut
down for short period of time and then restarted.
A dealer told me to run the quad with side panels removed to prevent this
problem and also insulate fuel tank from the engine and hook fan on a toggle switch to make it run all the time.I believe this to be a Yamaha
safety related problem which could cause serious injury on a hill.
minutes, after starting engine and under acceleration the engine lacks
power and tries to shut down until it is run for a few minutes. Only
happens on warm days. I relate the problem as I experienced on automobiles
years ago when the engine used a carburetor and when fuel pressure was
low and the heat from engine caused the fuel to vaporize in the lines. The
cure for that was to reroute fuel lines and make sure there was ample fuel
pressure and volume of fuel to carburetor.
When the engine on my quad is shut down for that period of time you can
actually hear the fuel bubbling and there is excessive pressure and
vapors coming from fuel tank vent hose. This problem never happens if you are running down the trail at any speed, only after it has been shut
down for short period of time and then restarted.
A dealer told me to run the quad with side panels removed to prevent this
problem and also insulate fuel tank from the engine and hook fan on a toggle switch to make it run all the time.I believe this to be a Yamaha
safety related problem which could cause serious injury on a hill.
#5
One of the reasons that i am posting, is so i will be emailed if anyone else reply's. My wife and i both have had no problems with this situation. As so, i hope that i never do! If the dealer is telling you to do these things to your bike, you would think that YAMAHA would pay for it. Like a safety recall. Boiling gas is a serious problem and maybe something that you should talk to the BBB or ??????? cant remember the other organization to contact when there is a problem???? Someone help me out here??? Anyways, i would definitely be calling and contacting everyone that i could about having that problem fixed. I have heard others on this forum have the same problem and maybe i am just lucky that it does not do it on our bikes.
Good luck and let us know what you find out!
Jonathan
Good luck and let us know what you find out!
Jonathan
#6
-One guy clains a few well placed holes in the side cover fixed it. Sorry if you don't like the idea.
-Another guy used muffler wrap, not the whole pipe, but where it passes the carb and tank area.
-That guy and others use Heat reflective patches (or tape) on the bottom of the tank.
My friend's 660 has not done this. It does depend on the amount of lightweight molecules in the gas. Heavy fuel molecules have to get real hot to boil. This sometimes changes with different gas stations, and the state you live in may have diferent regualtions that could affect this.
Don't ask me where to get the mufler and tank patch, but I have seen that stuff at places like dennis kirk.
-Another guy used muffler wrap, not the whole pipe, but where it passes the carb and tank area.
-That guy and others use Heat reflective patches (or tape) on the bottom of the tank.
My friend's 660 has not done this. It does depend on the amount of lightweight molecules in the gas. Heavy fuel molecules have to get real hot to boil. This sometimes changes with different gas stations, and the state you live in may have diferent regualtions that could affect this.
Don't ask me where to get the mufler and tank patch, but I have seen that stuff at places like dennis kirk.
#7
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#8
I race my Grizzly in Harescrambles and have never had this problem. Last weekend I raced in the Log Hopper for 2hrs no problems. Do you run more in high or low gear? I have heard that if you run very slow in low gear for extended periods of time that vapor lock occurs. Still I think it is bullsh%% that these machines do this. You would think Yamaha would have tested every kind of heat problem imaginable due to the size and the closed quarters of the engine. I have not raced my Griz in the heat of the summer months yet. Maybe this will happen? I will let you know.
#9
If Your only shutting down for a few minutes, Turn your lights off and leave your key on. If your engine is hot you will hear the fan run Let it run. It will not drain your battery down in 10 minutes if you make sure your lights are not on. It does get warm under there, I have seen a heat kit on Highlifters site.
2002 Grizzley
27" ITP 589's
Warn 2500# Winch
2002 Grizzley
27" ITP 589's
Warn 2500# Winch
#10
There are major discussions going on over at ATV Nation. I seems to be happing to quite a few rides. I am not one of the unlucky ones yet. Check it out at the address below....Arlan
Vapor Lock Discussion
Vapor Lock Discussion