2011 TXC 250 Fuel Pump Fails When Hot

I was riding single track for a long time in 85+ degree weather. My bike stalled out at the end when I shut it off and took a breather. Went to go turn back on and the fuel pump was not priming (you can hear when you push the button normally). We trailered it back and after it cooled off it started right up. Someone suggested that the pump screw itself swells up when it's hot and starves the motor (bike would still crank over). Any way to fix or mod the stock pump? Maybe like a heat shield or something? Or do I have to buy an aftermarket one? Thanks in advance!

You have aftermarket options. Ca Cycleworks has a pump with all the correct fittings. Replacing the pump is about a 1 hour job or less. EBay has pumps for less. You just take the tank off, pull the pump assembly and disconnect the pump from the assembly. You may be able to re-use the hose to the filter if you are very patient.

I would test that you get voltage at the pump electrical connector during your hot condition if possible. If there is no voltage, you may have a bad temp sensor. Check that you have coolant as well. I believe there is a temp at which the ecu will shut off. Not likely, but it's free to rule it out.

If you want to measure the pressure, I bought one of these and it worked great. https://www.walmart.com/ip/KCASA-Au...auge-Tester-Gasoline-Test-Tools-Car/325746211

It comes with all the correct fittings...for less than 20 bucks.

I have successfully resurrected a frozen pump... but it was not for my bike (which has the same fuel system as yours) and so I don't know if I permanently fixed it. In fact, I'm not sure what the problem is- most of the time it seems that the turbine hits the sidewalls and stops. but whether that's from varnish build-up or heat growth or what... I don't know. Cars don't seem to have this problem using virtually the same pumps, but ours are above the level of the gas for a fair part of their life- which would exacerbate either issue.

in Kurt's thread there was an excellent video of this:
http://www.cafehusky.com/threads/20...-hot-then-wont-start.86961/page-2#post-618332

You could try putting your whole fuel pump system (pump, lines, filter, regulator, including both plates) in a bucket and then put a quart or more of naphtha (or maybe mineral spirits, carb cleaner, possibly acetone?) and let the pump recirculate it for 30 mins or more. Check the temp- but it shouldn't get real hot 'cause it's not doing a lot of work (...until the turbine starts to contact the sidewalls at least). If the problem is varnish, in addition to heat, this *might* solve it. And you still may be able to re-use the naphtha (aka coleman fuel, white gas, or lighter fluid) for something.

what the hell- it's almost free. you might give a try. But take pictures for us, and have a fire extinguisher on stand-by

Then buy a cheap-ass ebay pump and see if that works.

good luck.

Thanks for the feedback. I feel like it has to be the fuel blade or screw swelling up. The pump is audible when priming when starting the bike normally. When she was hot we couldn't hear the thing prime at all and then sometimes you could barely hear it like it was struggling (we tapped it with a screwdriver). Another senior member of our riding group had mentioned that husabergs had similar issues where the fuel screw inside the pump would swell. It's just bizarre to me that this could occur as the gasoline itself should keep all parts running cool.

OT, I'm running 30 year old Coleman fuel mixed 1/3 with pump premium in my lawn mower.

I'm trying to get rid of the old can from the 80's in my garage.

It looks clean and runs fine.

I don't think naphtha "ages" like gasoline (because it's not a complex mixture AFAIK, and also doesn't seem to degrade with oxygen). My tin of coleman fuel is pretty old too.

A small amount of 2 stroke in the fuel seems to prolong this issue about 200:1. The pump even sounds different to running in straight gas. It has to be clearance or lubrication based issue.

You would think so.

However, I've seen bikes in tight woods boil gas to the point it was spraying out of the tank when the cap was opened! That particular bike was a KTM.

2013 -2014 TE310s boil gas all the time as they have very tight head to gas tank clearance.