okay, so a little background on the bike and myself. I'm a Harley tech, have been for 6 years, went to MMI, worked in aftermarket shops on everything from flatheads to twin cams. I'm no moron, nor am I a hack. i do things the right way and accept nothing less.



My bike is a 1980 FXEF. I Just finished a complete top end. ( it was .010" out of round on the front cyl and the rear ex guide had very excessive play) .040" over KB 9.5:1 pistons (.0015" clearance), rowe valve guides and valves,new valve guide seals, new piston pin bushings, new rocker arms and shafts.

running an andrews A/B cam, S&S steel breather gear, stock (not original) tappets with 4 known good hydraulic units. S&S super E carb, with K&N filter. Its a 1980, but does have o-ring heads with matching S&S manifold. Cycle Shack one piece exhaust with baffles.

Upgraded the points ignition to a compufire mechanical advance system.

EVERYTHING outside of the crankcase has been replaced or inspected and meets or exceeds NEW spec. Heads vigorusly check for cracks and warpage.


The problem. It misses at idle when its warm. It may do it 3-4 times at a stop light. if the idle is high enough it will recover on the next spark, if its too low, it dies.

before anyone blames the compufire, it did it with the points as well
Ignition timing is set slightly retarded from dead on the 35 deg mark to eliminate ping (it has a tiney bit with it set dead on)


all leakable areas of the intake have been checked (manifold to heads, manifold to carb and carb butterfly shafts)

spark plugs have been changed, from stock HD to autolight to bosch platnum.

coil has been check with new known good, as well as plug wires.

pushrod adjustment has been triple checked.

Head gaskets and exhaust have been checked for leaks with none found.


Basically I am out of Ideas. any help or ideas would be greatly appreciated.

 

do you think it might be a little lean at idle? The reason I ask is because my '72 does the same thing until it gets good and warm.

 

Have you checked indexing of cam, Could the gear have moved a little on you? Just a thought.

 

Could be lean at idle. You've checked about everything possible. Try a different carb.

 

I assume you have played with the idle mixture screw ! Do you run an insulator block between the manifold and carb? I had several S&S manifolds I had to send back due to porous castings You probably have already checked that

 

Could be wrong, but what type of coil cover are you using? I've seen both the form fitted ones and the rectangular one do this. Little more shake at idle sparks the hot end of the coil.

Just a thought

andygears

 

Dude you need to check the index timing of the cam gear , I've had nothing but grief from Andrews cams for shovels through the years , I've had them as much as 40% in timing out of the box . For a great cam look into V Thunder cams by Competition cams for your setup I'd go the SHV 4010 or SHV 4020 . These are made for hydraulic lifters where as the Andrews are really ramped wrong and beat hell out of the rollers . Also I take it your running stock hyd. units ? Well part of the problem is the oiling system , when the bike gets hot you lose a lot of oil into and around the lifters they are very loose from the factory and at an idle yo ucan see were this leads , you aren't getting the lift to the valves buddy ( this why everybody ran solids through the 70's & 80's for big cams ) If you can swing the bucks look into a set of Jims lifters for shovels you can get them to fit you blocks or got with the complete setup ( $$$) . They cost but they are worth every penny in headaches gone , I've run these in 93" motors with .550 lift cams with zero problems for years . From your post you got everything else right . The only other thing I'd really consider doing when down is dual plugging heads , ya I know this is a pain you really won't believe the difference it makes in a shovels attitude from starting on . My bikes a 72 running 93" (91hp) 11 to 1 comp ratio with the dual plugs , S&S hyd.lifters , .560 cam , Dyna single fire Ing. with the S&S "E " ( 1' spacer block ) and it's a one kick starter hot or cold , idles like a damn tractor hot or cold so ya it can be done . As a stop gap measure why don't bring your idle up a little as we all like to run shovels to low and open the mixture screw about 1/8 to 1/4 turn out or fatter and see what the results are ? Also the higher idle will help the oiling problem with the lifters . Oh ya you can also either get a spring kit for the oil pump relief valve to raise the pressure at idle or you can shim it yourself if your comfortable going there . Springs do weaken with time and use . At this point I'm out of suggestions and hope some of this helps . I've been doing shovels 39 yrs now and I,ve learned a few trick for them .............

 

PS You can find this stuff online fairly cheap through outfits like Jireh Cycles , Fog Hollow , Canyon Run , these are outlets for Midwest Cycles and Mid-Usa . Their chrome stuff is cheap but anything you need for a shovel motor or drive train repair parts I've found to be good stuff and it's as cheap as you can get . Good luck Doc

 

turns out it was a porus casting in the manifold. pulled it off and painted it with 2 coats primer and 2 coats cyl paint, and the prob is gone. never ran into that before. one of the techs i work with has seen it, and completely forgot about it. He actually built a rig to plug off both end of the manifold (off the bike) and another one to add pressure with a hand pump..... mine leaked like a siv.... through the metal (soapy water method). thanks all for the help!!

 

Is this Jerrod from Huntington Beach?

-Scott