Motorcycle Safety & Driveability: kickstart problems, harley evo, compression issue

Question
Hello William,
I'll get right to it.  I took my 1991 custom  Harley, evo engine, outta the garage today to introduce it to the new riding season.  It's kickstart with open primary.  I tried kicking it several times, putting all my weight (175)pounds on the kicker, but it wouldn't start.  No problem I thought.  What else to expect if it hasn't been ridden all winter.  So I take a 20 second break, then try again.  But now when I jump on the kicker, it turns needing only 20% of the force that usually is required to kickstart the sucker.  So I figured that somehow, I was not able to get any compression.  I looked at the primary and it would turn just fine with every kick, but there was no compression going on.  I could pump the kickstart with my arm and turn the crank. That's not normal.  How did this all of a sudden happen.  I figure the problem is a valve.  Could of the timimg chain somehow slipped?  Could it be a gasket?  Please help if you can. Could it be anything other than a compression issue?  I kicked the sucker over probably 100 times.  No combustion whatsoever.

Answer
Remi,

Since the engine is turning freely with no compression, sounds like a definite problem in the valve train.

I thought maybe the kickstart linkage might have been the problem, but since you say the open primary is turning, that is not it.

Again, since you say the bike has an open primary, it sounds like it has had a fair amount of custom work done to it. If it has had internal engine work, I would try to take it to the person who did the work.

If the problem is indeed the valves not closing, the cause usually rests in one of three places: the upper valve assembly above the pistons (usually the rocker arms), the pushrods, or the cam assembly inside the bottom of the motor. It is also possible you have two broken intake  valves, but that would be highly unlikely.

Any way you look at it, it sounds like an engine tear-down will be required. Total loss of compression like you describe usually means a catastrophic failure is some engine assemnly. Get a pro to look at it and don't try to start it lest you do a whole bunch more damage.

Best of luck,

Bill Roberson