Bike is hard starting when hot

[Jbaker229]

Don't know, have not tried, but I would think the issue would not be their because any residual fuel or fumes (which seems to be present during hard starting) would evaporate rapidly.

I do not know about your bike, but when the fuel tank is hot it is venting out fuel from the top vent which in turn goes into the built in charcoal canister inside the airbox. The canister then vents to the purge valve then down a hose to the intake manifold where the gases are consumed while running. With the purge valve always opened when stopped there are fumes building up in the intake tract.

My dad, who has 8 times more mechanical ability than me (thanks dad!), routed a vent tube from the charcoal canister out the airbox and down through the frame through the ground. For now it looks like the bike is starting correctly, I will take it for a long ride this weekend and let you know if it worked. Perhaps this might solve your problem as well?

[mackja]

I believe I have found the problem, I checked my charcoal canister and the glued seal around the top was not sealing, when the engine gets hot and fumes are venting into the canister fumes would leak into the airbox, this will cause a rich fuel mixture and the hard to start condition when hot. I thought I checked this previously but I just missed it. I have sealed the top lid with epoxy, hopefully this solves the issue.

[Jbaker229]

I believe I have found the problem, I checked my charcoal canister and the glued seal around the top was not sealing, when the engine gets hot and fumes are venting into the canister fumes would leak into the airbox, this will cause a rich fuel mixture and the hard to start condition when hot. I thought I checked this previously but I just missed it. I have sealed the top lid with epoxy, hopefully this solves the issue.

Excellent, let me know if it works!

[jdubxb]

I will need to check the canister thing as well as maybe the purge valve. I recently had two episodes of difficult starting when the motor was hot. It cranks and cranks but does not fire. The first time it happened, the fan started blowing as soon as I turned the key. Motor would not start after several tries. I tried holding the throttle WOT and that almost made it start; doing it again caused a backfire. Just when the fans stopped, I hit the start button and it fired up and I rode away. Not sure if it was just coincidence or if the fans being off was a "requirement" for starting.

The second time, the bike had been sitting for about 2 hours, no fan came on when key inserted. I don't remember clearly, but after several unsuccessful tries, I decided to hold at WOT and I think that is what got the motor running. But it also popped a "fuel pressure sensor" fault code. Unfortunately, I deleted it before riding off and I don't remember the code. The engine light was lit for the entire 45 minute ride home. The dash showed no fault codes were stored after I got home. The bike started up fine the next morning with no engine light.

I also checked the pins on the fuel pump connector (suggested on another thread) and they appeared fine.