Heat-related problem

[BigChiefWoody]

My '05 Rocket idles great. When I'm accelerating its smooth as can be.
When I ride it to work in the morning (75-80 F) it runs perfect.
Now here's my problem..riding it home from work (15 miles) the temperature is in the high 90s. Halfway home the bike starts to miss out. Its almost like the way my Bonnie acted when it was time to switch to my reserve fuel. Any ideas on this one?

 

[bertb]

Almost sounds like vapor lock. Have you done any re-arranging of the fuel lines lately? Does the fan kick in when hot?

 

[BigChiefWoody]

The fan runs when its hot and I haven't messed with any vacuum hoses..that might be a place to start looking though.

 

[atomsplitter]

Try checking your fuel tank vent. Sounds like your fuel pump runs out of suction. When the temps get high your tank pressurizes (unless you live in California and you have an evap cannister). That can shut the vent (phffft when you open the cap). If the vent remains shut as fuel is used a vacuum will exist in the tank lowering the suction pressure of the pump. It also can cause hot fuel to flash to vapor in the pump (cavitation). Simple to check, when the bike starts cutting out pull over and pop the fill cap open and see if it's under vacuum (it'll be harder than normal to open it). If that's not it then you haven't spent any money (yet). If it is, buy a new tank cap or clean the one you have.

 

[HellFire]

I took mine out this morning before the mowing incident and it ran perfect in 75 degree temp, yesterday it was 95 and it ran like ****. I think it's the alcohol in the fuel causing the high temp problems with mine.

**** corn subsidies!!!!!

 

[captain jack]

Come & ride it over here in UK, no heat problems here. (Sorry to be flippant) but to me it does sound like it's vapour locking.

 

[BigChiefWoody]

OK I rode it home..98 degrees outside. 10 miles into the trip it started missing again. This time I pulled over, turned the key off and opened the gas cap. No whooshing sound or anything like a vacuum so I decided to try riding with the cap open for a little bit. It did no good, still sputtered and missed out while riding at a steady speed. I stopped and put the cap back on and rode home cussing the whole way! Grrrr

 

[atomsplitter]

OK I rode it home..98 degrees outside. 10 miles into the trip it started missing again. This time I pulled over, turned the key off and opened the gas cap. No whooshing sound or anything like a vacuum so I decided to try riding with the cap open for a little bit. It did no good, still sputtered and missed out while riding at a steady speed. I stopped and put the cap back on and rode home cussing the whole way! Grrrr

That takes care of free. Does it miss like the plugs are getting fouled? Replace the plugs with new ones and see if it's still happening.

 

[Gothlander]

Check coil wires and leads for contact and splits.

 

[bertb]

Just a thought, tomorrow after work, go to a local watering hole and pound a few brewsky's. Wait 'til the weather cools down and then ride home and see what happens.