Unusual resistance when manually cycling through engine. (solved)

[cgguy09]

Hey guys,
I had a long thread on here earlier following an engine casualty centered around two sheared camshaft bolts. I wanted to break up the thread into my discreet problems so others can benefit when they search.

I rebuilt my engine and I have it all timed right, L at the top and LT is in a proper location; the correct cam bolts are in the correct holes; and the correct gap in the rocker arms. (2 of the 4 rocker arms are new as well) However, after mounting the engine and going through the spark timing, and other nonsense, I've noticed when the Right Exhaust Valve and the Left Intake Valve are being depressed, it offers a ton of resistance. To that very point, I can hear the engine creaking or squeaking when it goes through that motion. It feels completely unnatural when compared to the rest of the cycle. Which, is relatively easy to go through.

I dismounted the engine and took a look at the rocker arms and cam shaft. I did some musical chairs with the rocker arms to see if I could isolate when and where the stress was being placed. Oddly enough when I removed the Right Intake Rocker arm, it ran perfectly smoothly. I switch around the rocker arms and it seemed to be all better. I buttoned the engine back up, spaced the valves, and hooked up the electric start to test the compression. The Compression was a little off on the right cylinder, however, I instantly noticed it again was difficult to move through the Right Exhaust, Left Intake stage.

-I removed the cam-chain-tensioner to see if that would make it better. It did not
-I left off the top cover and watched the engine rotate with the electric start. I could hear a small "thud" everytime it went through the aforementioned stage.
-When I adjust the rocker arms, it has not affect on the resistance or the noise
-Before I dismounted the engine, I did a compression test: Right cylinder: 150~155 Left cylinder ~165


I'm at a loss of why I can set everything up and it feel fine, but after being cycled a few times it would be so resistant.
I'm considering braking down the engine to see if I can fix some unknown variable.
Is There anyway it could be a damaged Cam Shaft? is that even possible to really damage that big hunk of Japanese Samurai steel?

I'm open to any ideas. Thanks, gents.


To give you guys some background here are the facts

Prior Casualty: Engine ran great, then two bolts were sheared linking the cam sprocket to the cam shaft. This bent a valve and busted up 2 rocker arms.

Engine work: I got 4 new valves and 2 new rocker arms. The valves were installed, and were teste holding alcohol. The rocker arms are from a lightly used 1971 CL350, and are the correct angles (I went through the process of working with different RA before I knew the difference).

 

[cgguy09]

Re: Unusual resistance when manually cycling through engine.

Hey boys & girls,
I've got an update. I rebuilt the engine and its working perfectly. I don't know what could have been the cause but I might have a few ideas I'll get to in a minute.

I'm sure this piece of arcana is located a few places on this online motorcycle Mecca. But I want to emphasize the testing the motor before mounting it. It's something I never really did before, but it really is easy and can save you alot of time if you a IQ is on par with a monkey (like me)

To that end, some simple directions: (1) ensure your battery is fully charged. (2) Get a pair of jumper cables from your car. (3) Hook up the electric start [if you're uncool enough to still have one...like me] (4) Ground out the engine to the battery with the jumper cables [you can ground it anywhere on the engine] (5) Ensure your rocker arms/valve are properly timed & gapped. (6) ensure there is no gaseous build up/standing liquid from of gasoline, flammable substances[WD40, lighter-end oils, anything with an API above 36] (6) Say a prayer (7) and hit starter button (8) Listen for anything that doesn't sound right (9) conduct a compression test [note if the carbs are not on, and they need not be, your rating will be above that specified in the manual, probably around or above ~170, which is fine, just keep the cycles to a minimum] (10) If nothing happens, pray again, then ensure the bolt that grounds out the battery is in, or the battery is otherwise grounded to the frame.

I'll post some pictures.

So, in case anyone cares about my diagnosis of the problem, It would propose a few potential problems, if not a mutliple headed hydra of several problems.
-My timing could have been off (my L was slightly off cantor to the right, but barely so, I may have even imagined it).
-In the Cam System, the pin in my roller could have turned. (I don't have the rubbber in the pin, and I know alot of people don't) that could have messed up the timing if that was rotating or attempting to rotate
-The Rocker Arms were not happy where they were. When I rebuilt this engine the second time around, I did so placing my new rocker arms on the intake side and my previous ones on the exhaust side. The logic being that the new ones could close tighter (to .002) then the used warn-in ones. [Again, not exactly likely, but a change I made]

Beyond that, perhaps the Motorcycle gods were not pleased with sacrifice of time and money and chose to punish me.

Anyway, onwards & upwards.

Best of luck guys.

cFogs out

BT
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