Just got back,haven't even un-loaded my 650 Pra. yet.Here's the deal, We live in East Tn,it was about 95 degree's today and we were crawling alot and riding up some long steep hill's on Brimstone Mt, ALL the Grizz 660's started getting hot and vapor-locking,ALL SIX OF THEM,we would start up the hill's and they would start stuttering and loose power,REAL DANGEROUS,we took the side panel's off all of them and bungee tied them to the rack's, they still did it every once in a while and the heat was cooking my friend's leg's,By the way we are on "summer" gas now so Yam can't use that excuse anymore, needless to say my buddies on them were all pissed off bad.QUESTION, What can we do,I told Bryan about some folk's cutting vent's and while he was still mad said, we shouldn't have to cut a .... thing Yam should fix the .... thing's. I calmed him down and we made it home, A couple of them said they would be back at the dealer Mon. morning and they better fix them or there getting rid of them, My Pra. ran fine all day, fan ran alot but no overheating, never has, So what I am asking, Does Yamaha have a fix for this problem or are they on there own, They all said if they won't fix it, there Trading, It was real scary a couple times today grabbing them rack's when they lost power and wouldn't pull. I am not knocking the Grizz I love the ride and power and all but this problem has got to be addresed before someone get's hurt or killed.......

 

Any comment's?

 

Take some aluminum tape (the real shiny kind) & wrap it around the fuel lines & put some on the carb bowls. It should reflect the heat & help the gas from boiling.

 

Why should I or anyone else for that matter have to spend money to fix a problem that is not of our making. I went to the Consumer Product Safety Commission's web site and filed this report. Maybe we'll get some action. Others should do the same to show them that we have a real problem. Here's what i said:

The 2002 Yamaha Grizzly 660 atv has a problem with the exhaust heating up the gasoline in the carburetor and causing it to boil out of the Carburetor and back into the gas tank. This usually happens while you are stopped and are unaware that you have no gas in the carburetor. The pressure of the gas vapor prevents gasoline from flowing back into the carbuetor until under a vacuum from the engine. This has happened to me twice. When it occurs, the engine will sputter and almost stop running as it becomes starved for fuel. This happened once while climbing a hill and I was able to immediately stop and wait for the engine to cool down. A less experienced rider could of had a serious accident when losing power in a steep incline. I have contacted Yamaha and they claim to have never heard of this problem. On one internet site there are at least 50 Grizzly owners that have complained of this problem to no avail. The site is www.atvconnection.com . If you go there and do search under the Yamaha forum for vapor locking you will see what I am writing about. This doesn't appear to be altitude or temperature related as it seems to be happening all over the country.

Here is the site if anyone else wants to add their two cents and I wish you guys would.

https://www.cpsc.gov/incident.html

 

Minehunter is saying the same thing me and my friend's that own them are saying,"We should not have to fix anything ourself's, when you spend 7000 dollar's on a machine," and Yamaha not hearing of this problem is pure crap, the dealer in my home town has called them many time's and will surely do so again this week when these 6 Grizz's get parked back at the dealer,WHY is Yam in denial about this problem anyway? would it not make better business sense to "take care of the customer" instead of losing him forever? all I can say is my friend's are not going to touch these machine's,they should not have to, Yam should take care of them and if not then Yamaha has lost 6 customer's forever, and I can't blame my friend's one bit.........

 

I agree that Yamaha should address the problem. In the meantime a good fix would be to use header wrap around the header pipe to greatly reduce the radiated heat. Aluminum tape on the fuel lines/carb should help too like Moose mentioned.