Honda VTX Forum banner

Rough running - Carb blowing out gas & air

3K views 4 replies 4 participants last post by  Hans&Feet 
#1 ·
The problem continues for my 06 1300S - 93,000 miles - stock airbox - VTXexhaust mufflers - PAR removed years ago - engine breather off of airbox
This is a continuation of a thread posted a few weeks ago.

Some time back, when riding about 50 MPH and roll on the throttle, the engine would miss and sputter at full throttle. Ran fine otherwise.
A few day later - the missing and sputtering statrd at half-throttle.
Another few days later - missing and coughing at quarter-throttle.
Next day started running really rough above idle. Of course I'm over half way to work and finish trip. Engine was coated in gasoline on both sides and gas dripping out of the airbox. The air filter was soaked with gas.
Rode home and thurned the petcock on & off the whole 34 mile trip. Engine ran good for the few seconds before the carb bowl was empty and turn gas back on.

Earlier I suspected a problem with the ICM (CDI) and spark timing. Last night I determined I was wrong about the timing issue after swapping the coils. The ignition timing for both cylinders is good. It was operator error and bad viewing angles in telling the difference bretween an R and F on the crank stampings. Good thing I held off on replacing the ICM, HDL parts for $350!

The engine runs like there is full choke, too much fuel and not enough air, with gas and air puffing (blowing in pulses) out of the carb inlet. The ES (Enrichment System) checks out OK. All the vacuum lines are tight with no cracking. Fuel lines are good.

My next suspect is the carb. Maybe it's somehow feeding way too much gas to the cylinders. I will most likely remove it, strip it down, inspect and clean.
Are there any areas in particular I should focus on? All ideas and suggestions are appreciated.
 
See less See more
#4 ·
Update to Rough Running

Removed carb. Everything looks good from the bowl side and accel pump.
Took the cover off the piston slide and the piston diaphragm has a 1/4-inch crack/opening in one of the folds.

Could this be the culprit for allowing excessive fuel into the cylinders?
I don't recall seeing the piston lifting at idle and running very rough.

DLP is getting an order for the $74 vacuum piston. OUCH! :shock:
 
#5 ·
List>> $87.03; You could have bought for this much>>$60.05

Have you cranked the engine over to see if you are still getting blow back???
I had a tear in my slide valve diapgragm and had a loss of power at throttle
but no other issues..

If the float was not sealing and gas was flooding into the cylinder then it should get into the oil, and
blow back out of the crankcase vent tube...

Did you ever check the intake valve clearance???
A loose locknut would allow the adjustment screw
to move down---hold a valve open...
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top