Just finished up my hydralic tensioner rebuild, everything went great, new lifters new 204 cams new se adjustable pr, couldn't believe how easy everything went. So I get it all back together ready to hear her purr......but noooo. Press the start button she turns over great no unknown noises all sounds smooth but the bike won't start. Check everything and find my plugs aren't firing, I've done nothing to anything that should affect the firing. I've been through the flow charts in the manual, checked fuses, checked for codes, man I'm stumped! The only thing I notice about the plugs firing is every now and then when I'm turning it over, just as I let off the starter button I get one spark from the plug. Any thoughts?

 

So no codes?

Thats a really weird one, got me completely stumped.

 

The one spark when you let go of the button is normal, the ECM is turning off the coils because the motor isnt running and the coils discharge across the plugs.

That means the coils have power, and are talking to the ECM, but the ECM isnt firing them.

Did you check the crank angle sensor?

 

WHOA, Crank angle sensor? Went over me with that one, where might that be?

 

It sounds like the crank position sensor, or cam position sensor, but it should be throwing a code for either of those. Did you put on some kind of tuner after the cam install? Check all connections, good luck.

 

Had a tuner on it already, running a Dolbeck tuner, where is the cam position sensor I don't recall seeing it in the cam chest.

 

Crank angle sensor is at the front of the engine near the downtubes.

I cant imagine why it would have a problem since you didnt go near it to do the cams but anyhow.

 

Twinkies dont have cam position sensors, just crank sensor.

 

Had the same thing happen to me. Happened after trying to remap. Had to take it to the dealer to get a stock flash. Takes about five minutes charged me 18.50

 

Remapping after cam change? I haven't even touched the tuner yet. Never got that far. Maybe I should just take the aftermarket tuner out of the line.