Help! Husky SMR problem

2008 Husqvarna SMR 510 track bike. full arrow exhaust, stock ignition system.

Having issues with major hesitation when the bike is wide open or under any heavy acceleration.

Bike gets warmed up and will perform without any problems and run great for 5/10 minutes on the track and then the problem will start to occur and slowly worsen with each lap. Bike will not pull through the hesitation if throttle kept wide open. When bike cools down between sessions the bike will perform better at the start of the next session but will quickly develop problems again.

What I have worked on so far...
Valves in spec
New fuel pump
New ignition coil
New plug wire and multiple plugs
New water temp sensor
Injector/throttle body cleaned a few times
Connected to Ibeat shows no current errors.
-history showed multiple "Injector - open circuit" historical fails. Cleared and has not shown again after riding and experiencing problems
JD tuner installed - adjusted fueling to max and min settings with same problem. Tuner disconnected did not fix.

Thinking I am trying to find some sort of heat related issue with either an injector or electronics. Hoping some Husky gurus out there might have a few suggestions?

Thanks

Sounds like you've got a rich condition at wide open throttle. As the bike heats up, it wants to run leaner and leaner. Usually fuel injection will make it run rich at wide open throttle. If it were a carb, I'd say change the main jet to a smaller size, but on FI I don't know.

Air Temp sensor? Throttle Position sensor intermittent? ECU intermittent? bad wire? bad internal fuel hose? fuel filter? pressure regulator? water in electrical connection turning into steam? gas tank vent blocked? (open the cap)

I'm totally stumped. sorry.

How old is your battery and did you change the fuel filter when you changed the pump? Our bikes require at least 9-9.5volts to run. Somethings obviously heating up and causing the issue.

Fuel filter is a good thing to try. It's probably one of those sensors. MAF or equivalent on these bikes is the most likely cause. Unfortunately, it's nearly impossible to check them with a volt meter, so you may have to throw sensors at it. Is the ECU advanced enough to keep data and throw codes?

Check that your valve clearence is in spec and if so, maybe you should have +0.01. Some times it is a closed valve and when the engine gets warmer the metals expand and you have a problem with heavy acceleration and idling

all good comments. i would do the easy ones first, fuel vent, check all electrical connections in areas of high heat. do tend to think it will b a sensor myself. and do make sure that battery is in top flight condition.

Any progress? let us know what you find out.

was there ever a solution to you problem? getting a similar "open injector circuit" on my 310. Im thinking its a wiring/connector issue but not certain. any insight would be helpful.

Thanks,

Dan