My Grizz has 45hours on it lots of mud riding here in florida.
The other day my brother told me he read about the gasoline boiling in the new grizz after low speed riding well I thought it was his polaris propaganda. Heres the deal this saturday was the opening day of hunting season well after riding about 15 miles thru grass ponds palmettos and scrub oaks we stopped for a break and I smelled gas fumes but ive always smelled gas on my grizz but never found any leaks but this time i heard a gurgling sound and looked closer, take the gas cap off and you can see the fuel at a slow boil sticking my finger into the gas reveals its warm but not overly hot so it must only be boiling in the in the lower left side of the tank which is the opposite side of the exhaust With the cap on the vent tube spews a large plume of gas fumes into the air and with the vent tube in its proper place the fumes are blown on to the engine this is very dangerous boiling continues for 30 minutes after shut down
The dealer say he has never heard this and unable to recreate this with out a long hard ride cant do any thing. yamaha customer service
says they have never heard this and to tell the dealer By the way both dealers in my town are idiots who dont know anything I guess somebody will have to be severly burned before they take notice any comments collaboration or ideas accepted

 

I have not seen this problem on the 660 Grizzlys yet, but some of the 1998-2001 Grizzly 600s had this problem. The heat from the exhaust heats the floatbowl on the carb. so much that it would cause the engine to run poorly. Yamaha had a service bulletin on it that required a heat shield that surrounded the carburetor on the exhaust side to keep the heat from getting to it.

Keep in mind though that the problem you describe really isn't that big of deal until it gets hot enough to turn fuel going into the engine into vapor causing vapor lock like the 600s. A lot of different machines from different manufactures do this but no one notices it.

Go back to your dealer and mention the bulletin on the 600. The shield looked pretty universal. It might be the fix for your machine.


KNOWSALOT

 

There have been extensive posts about this on the High Lifter forums at www.highlifter.com. Mine has done this also. I acutally think its boiling in the float boal. It does vapor lock ours and the quad dies. I called my Yamaha dealer and he told me that if it were boiling it would of blown up. Aparently he is not a physics major. I do see this as a big problem. Just by looking at the machine you can tell Yamaha knew it ran hot. Take a look under that heat shield by the airbox....they stuffed it with muffler packing to help cool it, but that doesnt work. To me the heat is the only downside to this quad.

 

was there any explosions on the old 600's or anything that can damage my quad or me for that fact?

 

I won't go as far to say it has never happened, but will say that I haven't heard of any explosions.

If there were explosions, Yamaha would have issued a recall on the 600s to fix the problem.

There have been more complaints about this machine in the past few months regarding so many different problems, I've begun to wonder just how much R&D went into producing this machine. Nearly every model from every manufacturer has a problem in its first year out, but the 660 Grizzly, as nice of a machine it is, would have to be the worse example I've seen of it since the Kawasaki Prairie 400 in 1997.

KNOWSALOT

 

although I do like the comfort of the seat and the smooth ride I find myself worried about this machine alot i ride in alot of mud and water and i must say my belt has never slipped but the little drain tube on the front cooling tube stays full of water and it sounds as if this has caused the clutches to get dirty and noisey I thought about taking the cover off to clean inside but i dont want to cause another leak or strip a bolt hole or something. I guess what Im saying is its an awesome riding bike but I have always had and abused a honda foreman that would not die and I just dont feel this bike will stand up to that standard. If someone would give me $6000 for my grizz I would go buy the Foreman 450S with 26 Mudrunners
that I was gonna buy in the first place ??

 

bttt

 

hay Danimal FL, my grizzly boiled its gas today wile i was at work. I use mine to spread grass seed for a local timber company. today wile creaping around at slow speeds upand doun hills mine started cutting out and dieing on me i could smell gas and hear it boiling in the tank when i looked in the tank it was not a slow boil but a fast dangerous boil. I cant understand why this is happening the engine does not seem to be running eny hotter than its supost to and the temperature light never comes on you would think if the engine was that hot it would melt the plastic tank but it doesnt. i thingk the tank is mounted to close to the top of the engine and all the plastic is traping in all the hot air around the tank and carberator. i told my dealer today after work and he doest know anything about it. i supose this might not happen if i didnt ride it so slow but i bought this bike to work with and you have to go slow to spread grass seed. my sportsman 500 i use for 6 years and never boiled it gas doing this kind of work. i forgot to mention each time the engine would die gas would spray out a vent tube doun near the left flour bord

 

The problem isn't with the engine getting hot.

The problem is that the heat from the exhaust pipe is heating the carburetor float bowl.

I wanted to also state a fix to a problem some of you guys were talking about earlier in the week.

Some of you were having problems with the left side CV axles coming out of the differential. We hadn't seen this problem until Tuesday when we had 2 units come in with the same problem. Yamaha sent us two new snap rings that are slightly larger in diameter to hold it in place.

You can notice the difference in size just by looking at it. They were only $ .50 each! Pocket change.

According to the guys at Yamaha that I spoke to, There was a slight manufacturing problem. The problem was that the differential, where the shaft goes in, was machined to a tolerance greater than what Yamaha had specified to the vendor. He also said there have been NO reports of the problem on the right side axles.

Just thought I would pass that along to you guys just in case you haven't gotten it to your dealer yet.

KNOWSALOT

 

Hay Knowsalot, you were right about the exhaust pipe causeing the vapor lock in the carberator and the boiling fuel. All i did was leave the two plastic engine covers off while at work today and there was no boiling or vapor lock . But i wish there was a fix for this problem it looks better with the covers on.