Expert: Bill Silver - 12/13/2008

Question
QUESTION: I hope you have time for this. I found this bike a while back and it had been sitting for a long time (35yrs). When I initially got it it would kick, not fire but turn over when kicked. I have not gotten into the motor at all as I did not think I would have to. I know, silly me. Problem is now it will not kick over at all. I do not know much about bikes but I can fix stuff. Is disassembling the motor/head the next step, and if so is there a diagram on line anywhere, not instructions so to speak but at least an  expanded view. Is this even where to look next?
  Any help would be greatly appreciated... I really like this old bike and would love to see her runnin' again.

ANSWER: Cody, the CL90 was my first motorcycle a long time ago. I rode one 1500 miles in three days, in my foolish youth. They are pretty rugged, but do need maintenance and care... and a battery! If you are trying to start the bike w/o a battery you will do more harm than good. The ignition system requires a 6v battery to run the engine. With a good battery, the ignition points need to be cleaned and gapped to .014" and the point plate adjusted so that the points just OPEN at the F mark alignment on the flywheel/rotor - stator alignment.

When bikes sit for that long, often the pistons stick in the cylinder bores because of condensation buildup inside that rusts the rings to the cylinder walls and glues the rings to the piston grooves.

If it still turns over, you have to check the valve clearances at the top of compression stroke and verify that they are .002" loose.

You MUST have a clean fuel system, from gas cap vent to the carb float bowl. There are tiny holes in the jets that become plugged up with evaporated fuel solids and that prevents them from starting/running well. Everything must be clean and clear.

If you have access to a compression gauge, check to see if there is sufficient compression to fire the cylinder off, properly. If you keep kicking and kicking when there are unchecked/unrepaired issues with compression, spark and fuel metering, you will eventually break the kickstarter shaft, which will require an entire engine teardown to repair.

On-line microfiche illustrations can be found at www.cmsnl.com

Bill Silver

---------- FOLLOW-UP ----------

QUESTION: Hi there, it's me again...
OK, I got everything unstuck and put back together, it all seems to turn smoothly. Carb looks good, I cleaned it all up, replaced fuel lines, spark plug, have a battery ordered, I think I'm good to go but I'm wondering about this new fuel in an old bike, any thoughts or recommendations? Thanks in advance... Cody

Answer
Cody, congratulations on getting it all back together again.

As far as fuel goes, even though these were built in the time of leaded fuels, the designs and materials are still compatible with today's unleaded fuels. I just use premium fuel in my bikes, because of the higher octane, but don't worry about any other fuel additives. They are not necessary.

Bill Silver