Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[efrbc1]

Buddy has a 2000 non-CVO Fat Boy.  Bike sat for about 7 years.  Non-FI so he removed and cleaned the carb and lines.  Bike will start but does not run well.  Says he can pull the rear plug wire with no change in how it runs.  Pull the front wire and it stops.  He has spark to the rear plug - new plugs and wires.  Compression tests at 150 both cylinders. 

Kind of scratching my head on this one.  Crank position sensor??  Anyone got any thoghts??

Thanks,

Chris

[cahdbiker]

efrbc1, you could pull the CPS and wipe it clean then give it a try. However, when the CPS went out on my Heritage, it has a S&S 107 in it, it would run okay for a little bit then stop, wait fifteen minutes it would start up and do the same thing. If he is getting spark to rear cylinder all the time then it has to be a fuel delivery issue. If it gets fuel and spark it should fire. I would try a different coil. It could be that it throws a spark to the rear cylinder intermittently JMHO CAHDBIKER 

[Doc 1]

Buddy has a 2000 non-CVO Fat Boy.  Bike sat for about 7 years.  Non-FI so he removed and cleaned the carb and lines.  Bike will start but does not run well.  Says he can pull the rear plug wire with no change in how it runs.  Pull the front wire and it stops.  He has spark to the rear plug - new plugs and wires.  Compression tests at 150 both cylinders. 

Kind of scratching my head on this one.  Crank position sensor??  Anyone got any thoghts??

Thanks,

Chris

The pilot jet in the carb is bound to be clogged totally shut and the holes in the emultion tube are more than likley clogged as well. A good cleaning of the carb and replacment of the pilot jet would be my first move.
Doc

[GMR-PERFORMANCE]

I am amazed that it started at all. As Doc said clean the carb move on from there.

[HD Jim]

Does the rear cylinder have compression?  Maybe a valve is sicking partially open.

[efrbc1]

Thanks for all the suggestions - tried every one.  Swapped coils with new - same problem.  Carb was cleaned and all jets replaced - same problem.  Compression is 150 in both cylinders.  Now you see why I am scratching my head on this one.  Anyone else?   

[timo482]

save some headache - swap a carb on from a good known running perfect bike

if the engine runs right with a known good carb the carb still is not fixed.

if it still wont run it has a electrical problem that is not showing when its assembled OR it has a mechanical problem that only shows at rpm above what the compression test shows.

could try put in a compression gauge in rear cyl and run the engine and see if it stays up

to

[brassspike]

Pull the rear plug. Wet it real well with gasoline and install. Leave front plug wire off. Replace the rear. Crank the engine. If it fires and dies you have someting blocking the mixture going to the rear cyl. Pull the intake and see whats going on up in there. 

[timo482]

oh yeah! forgot about mice!!!! could be clear down at the valve...

that will do it every time - if thats the case and it ever does run? fire everywhere!

to

[Razorback]

Make sure you still have a seal on the rear intake to head.

[HD Jim]

Is the rear plug bad?  May not be firing or firing through cracked insulator inside.