New-member and new-re-owner.
Hi from sunny and warm South Carolina. Picked up a sentimental project. My dad had a cl77 and brother and I used to ride it in the school yard with my dad having to catch us when stopping, since we couldn't reach the ground with our feet at that point. Big fours came out in the 70's and the Honda was sold for $200. Been wanting one since Pop's passed, and found a fairly complete one down here and have been sorting out the bike with excellent guidance from this forum. But, got an issue I can't figure out.
Some back story, runs but rt cylinder does not get as hot as left, lots of backfiring from rt and carb flange on rt is warped. Power seems way off too. Pulled carbs, cleaned, etc and was ready to put all back and went to adj valve clearances. As I rotate the stator per Bill Silvers, and clymer manual, the valves should be fully closed as the T or TF is lined up. But, both exhaust valves seem to continue opening for maybe 15-20 deg or approx 5/8" past mark. Pulled the head cover and the 0 and flat side of sprocket mechanism are on top when T is aligned with mark.
Any ideas?
Thanks, LF. (Jeff)
Introduction and a valve timing question.
To check that the stator hasn't spun on the crank, just pull the plugs and see if one of the pistons is at TDC when the T mark is lined up.
Remember, both valves (intake and exhaust) will be closed when the piston is at TDC on compression on that cylinder. You don't need to even use the T mark on the stator, just bring one of the pistons to TDC, confirm that both valves on the cylinder are closed (not moving), and set the valve clearance. When you had the carbs off did you check that their mounting flanges were flat? It's not uncommon for them to be warped. Ideally you want to pull the carb straight again, but that's a rather involved process. Next best thing is to surface them flat using wet/dry paper on a surface plate, old mirror or piece of glass. Use new O-rings, installed with grease, don't over-tighten carb mounting nuts, check that slides move with complete freedom. Do what you've always done and you'll get what you've always had.
Nick,
Thanks. Just checked right cyl and at Piston TDC the T mark is lined up and the exhaust valve is still closing and the "0's" on cam sprocket are on top. I believe the intake might be opening early too. I am way confused. My right carb flange is warped and assuming it was part of the odd running/ idle, etc. Is there a procedure for pulling it flat vs. sanding it? Thanks, LF
Remember, on a 4-stroke engine (like yours) the piston goes up and down twice for every power stroke. That means that after the spark plug fires and pushes the piston down, the next time the piston comes to TDC it will be on the exhaust stroke, pushing the exhaust out the port. So if you line up the TDC mark on the stator and the exhaust valve is moving, the piston is at TDC on exhaust. You have to rotate the crank another 360 degrees to bring it to TDC on compression, at which time both valves will be closed.
That's when you adjust the valve clearance. Do what you've always done and you'll get what you've always had.
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