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Quote from: gmoneymagna on October 30, 2018, 11:07:37 AMI'm not sure how this bent valve could have occured as it was not having these symptoms before the valve adjustment which I did correctly to the best of my knowledge. There was slight upper engine noise before adjustment. Do you think it could be caused by something else causing the mixutre to ignite at an innapropriate time while the intake or exhaust valves are open?As to the last question, no. The valve bends with some mechanical interference. In a wasted spark system, it is normal for the spark plugs to fire between the exhaust and intake stroke. Maybe some valve open overlap at that point. No biggie.If the valve guides/valve stems get a carbon build up on them, they can't slide smoothly and can hang open. This would allow the piston to come up and smack the valves. Improper cam timing can also cause this.On the 550, reinstalling the cam cover/cylinder cover improperly can also bend valves. I don't know if the 650 shares this procedural danger. Has the cam cover been off the engine since new?They don't have to bend much to cause sticking. Some have reported hearing the valves snap shut while turning the engine over slowly by hand.Back in the 50's and 60's OHV engines using the non-detergent oils available at the time, frequently had valve sticking issues. Over the counter additives were offered to "clean" the valves and loosen them up. I think all the detergent oils already have such an additive since then.If you have been using the proper oil in this engine, I think carbon on the valve guides is unlikely. But, what of historical treatment/maintenance of this motor?Anyway,the leakdown test should reveal if you have an issue there.Good luck!
I'm not sure how this bent valve could have occured as it was not having these symptoms before the valve adjustment which I did correctly to the best of my knowledge. There was slight upper engine noise before adjustment. Do you think it could be caused by something else causing the mixutre to ignite at an innapropriate time while the intake or exhaust valves are open?
Gmoney,Does this popping puffing intensify when loading the engine as slipping the clutch to take off....?Have you checked #4 spark plug for proper gap and condition (color) compared to another properly running cylinder...?Have you tried moving spark plug #4 to cylinder #1. To see if the popping moves to #1......?And you have seated all your carbs And rubber intakes completely on the spigots...?Your previous post indicates carbs on right side may have slipped back.Have you corrected fuel leaking out of #4 cylinder intake..? Sometimes a dead cylinder (non-firing) cylinder will intermittently hit and ignite a poor air/fuel mixture from a malfunctioning carburetor. But this would not pop (reversion) back through the carb.Try compartmentalizing your tests. Verify Ignition is functioning normally on cylinder 4.#4 carb float is not the source of your indicated fuel leak.Leak down test cylinder #4 to ensure intake and exhaust valves are seating.A good compression tester could hint of a problem when compared to a good cylinder. Not as conclusive as leak down tester but you'll still have to compare to a good cylinder.You'll find it, just keep after it.
Gmoney,After rereading all your post, I would try to get the bike running as well as "before lash adjustment" prior to synchronizing the carburetors. The bike will have to run properly with out the choke on before synchronizing with any kind of success.Stay at it a post a video with sound of it running and taking the choke off slowly.
