'07 700 FI ~ Gas Boiling !?

[Colorado Yamaha]

Anyone have a problem with the gas boiling and keeping high pressure in the tank? Enough pressure that it made an audible noise and blew off the cap, once I turned it a little. Happened to me this past weekend, not sure if it's the heat from the exhaust or what? Yamaha has been notified, no word back from them. Anyone else?

 

[clutch]

A friend of mine with a new 700 rode over 600miles this winter in Arizona and didn't have any problem like you describe. The temperature was in the 60's to the 80's with lots of slow rock crawling in the dry washes.

 

[Jevil]

Hi!

Actually we had that same effect with 660 Grizzly. And it was even so bad that it causes overflowing on carb... The tank cap vent was allso too small to release all pressure.
For solution we did drill the hole just little bigger on the cap and it worked well. We never have to stop with same problem again.

 

[frantzm67]

I dont own a 700, but I have watching them, ( really wishing I could afford one). anyways I thought they moved the gas tank under the seat just for that reason to get the tank away from the heat over top of the engine. I know that there was a problem with the 660 which I did run into early when I first bought mine in 02. just curious with this maybe something else involved.

 

[Colorado Yamaha]

Update

Thanks for the posts guys, I love these forums! Yamaha has ordered a new vent valve thinking mine is stuck or did stick. In the meantime, I wrapped the exhaust with header tape under the stock heat shield and then wrapped the heat shield with a 7"x24" 2000 degree heat blanket; I can't be down longer than a week waiting for the pipe to be Swain Tech coated so this will have to do for now. I suspect there is more heat coming off the motor but can't imagine it's enough to get that hot. Going out Sat & Sun and will take temp readings ga'lore and report that info back to Yami. I'm not happy being an unwilling guinea pig for Yamaha again, first with the new Viper, then RX-1 and now this, but I love this new FI so much I'm spending my own $$ to get it right.

 

[MrSled]

This was a problem on the 660s but I know they came up with a kit back then to prevent that. I have never had the problem but did the update.

 

[pat the rat]

ya,same here,had the update done on my 03 but never actually did it,the new side pannels were a part of that update

 

[Jaxom]

I think that the 660s and the 700s have different issues. The 660 seemed to actually boil while the 700s have more of a venting problem.
http://www.nyrocatv.com/techtip.cgi?vie ... iewtip=331
Nyroc has a lot of good info.

 

[Colorado Yamaha]

Still Working

Update: the new overflow vent was not the problem, Yamaha then put in a new fuel pump 2 weeks ago. Rode this weekend, I still get LOTS of pressure in the gas tank and when I opened the tank, the ATV stalled when letting off all of the pressure.

I think the new design of the side panel won't allow heat to excape easy and it just gets way too hot. Luckily ~ I have Yamaha's ear on this, so they are actually being proactive in helping diagnose this. Taking it in Friday to get additional heat shielding put in around/under the tank and they will look into cutting vents into the side panels.

 

[Jaxom]

Good info, keep us up to date.

Thanks

 

[HIGHLAND_GT]

COLARADO YAMAHA
I TOO HAVE THE SAME PROBLEM AND WHAT I DID IS TO INSULATE THE BOTTOM OF THE FUEL TANK WITH A PIPE WRAP THAT IS FOIL ON THE OUTSIDE AND FOAM INSULATION IN THE MIDDLE AN ADHESIVE ON OUTSIDE. THE TANK IS NOT TOO HARD TO REMOVE. THE INSULATION I GOT FROM A PLUMBING STORE.
THE SECOND IS TO GET THE UPDATE PRESSURE RELEASE OFF A DIRT BIKE SUPPLIED BY MY DEALER. I HOPE THIS WORKS FOR YOU.
HIGHLAND GT

 

[Colorado Yamaha]

I ended up wrapping the exhaust with standard exhaust wrap, then the dealer installed the heat tape to the bottom of the tank and they put in a SLP filter on the top of the tank housing to let heat out. I later drilled 6 - 3/8" holes around the gas tank fill plastic, lots of heat comes out of there also. Since then, I haven't had any problems but it was coming into fall and I only have 238 miles on it. I should have returned the damn thing right away and waited a year or two then bought one. Live & Learn.

 

[suburban]

Was anything changed for this on the 08's ?

 

[Camo7]

Just had the same thing happen this weekend. Hot day and some slow crawling through the muskeg. Once we were out and had the ground speed back up, the tank cooled down. Let me hear of any sucess stories on fixing this.
Thanks

 

[pat the rat]

i do get the boiling gas but my cap never blew off,ive heard some people installing an old style cap with a hose in the middle,might help