During yesterday's ride I was noticing anytime I slightly loosend the gas cap, there was a noticeable hiss and then the motor would almost immediately lose RPM. The guys behind me said it smelled like the motor was running rich also. I finally took the cap off and saw the gas "boiling." I just nursed it the rest of the day and brought it home. Noticed this evening while cleaning the mud off that the heat shield on the bottom of the gas tank was missing.

Any recommendation on what to replace the shield with? I'd like to replace it with something that is better than stock if possible to ensure this doesn't happen again.

 

Anybody?

 

Was the gas actually boiling or was it a venting problem due to higher temperature. The 700 Grizzlys had what everyone was calling boiling gas which was actually a venting problem. If it was boiling your gas tank would be very hot as well as the gas. Did you actually check the temperature at the time?
Take care,
Dave

 

I could feel a lot of heat by holding my hand above the spout after taking the cap off. There is definetly a heat issue. I'm looking at products like this to reflect the heat

I know the Grizz had a venting issue but haven't heard of a Sportsman having the same problem.

 

i hadnt heard of anyone having a boiling gas issue as i would think it would vapor lock the engine but maybe not. i would be putting as you stated some type of heat reflective matial for sure and keep an eye on it as well. thats the bad part of these big bores as they throw off so much damn heat.

 

Went for a ride yesterday and after about 2 hours riding in 100 degree heat I could swear the gas was boiling also. When I stopped I could hear what sounded like a tea kettle wistleing noise. I removed the gas cap (lot of pressure) and could see gas bubbling or boiling in the tank. After I replaced the cap the wistleing and pressure started back up again withing a few seconds.

Did you ever find out what was going on with yours? Was it something to do with a gas tank venting problem?

Thanks

 

Remember guys, fuel can ignite without a spark. Temperature is what causes the ignition. Don't play around with this get it fixed. Doc

 

What machine is this issue on?

 

I've read about this.......I was looking into getting a yamaha before I bought the popo......

All my research pointed to that it is not actually boiling. It is in fact a venting issue and can be caused from overfilling the fuel tank and there was also a cause listed as a poorly designed vent system.....seems like you just had to replace to replace a small valve or something......not supposed to be a big deal...like $10 or something.

 

There was a nice article in ATV Action mag on cooling issues.

they make i nice kit for tanks and lines. Basicly it wraps and insulates anything with heat or cool characterics.