sportster

[wissportster]

Had my 99 sporster out the other day. We rode for around 10 to 15 min at around 30mph. Sat on a sandbar for 1/2hr to an hour. When we took off (eng temp and pressure ok) got up to about 3000 rpms and the motor dropped down to around 2000. Any ideas or suggenstions? I know there is a sensor that has the motor do this but everything checks out. It almost felt like vapor lock, but temp was not hot?!? Appreciate the help.

[tvano]

iirc, if the temp sensor goes belly up then the ecu thinks that the engine is cold and limits rpm until some minimum temp is reached. if the temp sensor is sick the ecm never sees that temp. threshold and you never see the rpm you want.

[SmoothWaterMan]

What engine do you have in it?

Peter