Have a pretty much new 700 EFI - only has about 470 miles. ATV lives at 8800 feet and is riden from there to mostly around 9500 feet and sometimes up to 12k. The low miles are due to the problem I have, can't ever take it out. Never get any codes or anything in the display.

Numerous occasions when riding, easy riding, unit will just loose power and stall. Let it sit for 20-30 min's and it starts and runs fine. Had to tow it off the mountain 4-5 times. Thought it was an ECU issue, took to first dealer twice, they found no issues, no codes, then next year took to (2nd) dealer and they wanted $100/hour to drive it and try and recreate the problem. They suspected fuel pump problem & said $600 for a new tank assembly. So, I applied heat tape to bottom of tank then wrapped exhaust twice, added heat shield to the gas lines, added vent holes in the red side panels to help get air moving.

Tested & no luck. Last week - pulled tank and removed fuel pump ... took to dealer and it tested ok, filter was good also. Added one of those heat blankets to the bottom of gas tank & tested again this weekend. It did stall but only for a short time, maybe 10 min's or less and it was cool air temps at 12k feet! Outside gas tank was 127 degrees and gas was 99 degrees, had an '06 800 there also and temps were within 10 degrees on both (but 800 was less). New 91 octane gas has always been used to remove that consideration.

Anyone know what gets hot and causes it to die/won't start or idle? A particular component? I've wanted to sell this thing for 2 years but I can't even do that when it can't be relied on. Any ideas?

 

You may have a vent line issue. Make sure it is clear/unobstructed. If the vent line isn't functioning properly it could cause the issues you're having.

 

did you take out the fuel pump when it was acting up? when you turn the key back on after it stalls when trying to start to you here the fuel pump working? if not then you have a bad pump that kicks out when it heats up. not so uncommon if you search the forum you'll see a few. look at my post up in the sticky threads for an aftermarket replacement w/ out replacing the expensive fuel tank if that is the problem.