Engine Turnover

[Joab]

So...when I try to turn the crank by hand (going in the proper direction of course) It seems to "catch", and not want to turn any further. If I hit the starter, however, it turns over fine, no terrible noises of a valve getting chewed on or anything. Is this normal?

[CatatonicBug]

Is this with the spark plugs removed? If the plugs are still in, rotating the engine should create pressure that should make it difficult to rotate. If it still "catches" with the plugs removed, then you have a problem.

[Joab]

Once I get the new oil seal in, I will try pulling the plugs and turning it over then. Thanks Bug!

[Rasputin]

If it was a valve issue it is not now that he spun it over with the starter. Word to the wise is if it will not turn over by hand then STOP. If it is something as simple as compression better to find out before you ruin stuff. Hope you are ok and you did not bend stuff but if you do not know ask first. Heartache an be saved bigtime.

[Joab]

If it was a valve issue, things have probably been damaged for awhile, since I haven't messed with anything in that area, and nothing has changed since the bike ran. I guess I am assuming a valve getting chewed up by the piston would make a noise? Maybe not.

I will pull the plugs and take a look see inside anyhow, worst comes to worst, at least I can figure out if it is scrap before I take the next load of metal to the salvager.

[jjz28]

I did a compression test on mine and they were all over 170 so with the plugs in, it would probably be hard to turn when it hits the compression stroke on a cylinder. So, as said, removing the plugs should make it easy to turn as there will be no compression. Remove all plugs though.

[Joab]

Sounds like nothing to be done but pull the plugs and go from there. Hopefully sometime next week the new oil seal will show up, and I can get back to troubleshooting.

[skids]

If it was a valve issue it is not now that he spun it over with the starter. Word to the wise is if it will not turn over by hand then STOP. If it is something as simple as compression better to find out before you ruin stuff. Hope you are ok and you did not bend stuff but if you do not know ask first. Heartache an be saved bigtime.

GOOD advice given here! Prevent bent valves now!

[ddragon63]

Compression on Old Man is 167 to 173 on all 4.. I can turn mine over with a box end wrench, with plugs in.... of course when you hit a compression stroke it is a little firmer. But not like a catch, just harder to push. Hopefully you don't have something tatered in there.

if you were crowning valves with the piston you would hear it, trust me... when your valves start beating smiley faces into your pistons they make a good *chonk* *chonk* noise as it rolls over on the starter.... right untill the head of the valve breaks off, valve bends, or they just lock together.
But its best not to think about that

[Joab]

Lol, very reassuring Don...luckily, no chewing noises from the engine as of yet.

[Rasputin]

I was not saying that you likely bent a valve. I am simply stating that if anyone who reads this thread has an issue like that, it is a poor idea to use the starter. You have to remember that for every forum member on here there are umpteen dozen lurkers who read everything we say and then go try it. Usually once they follow some less than proper ideas in a thread they join the forum to ask what happened. I was one of those lurkers for a while myself.

[trbig]

Between the crank and the rods acting like fulcrums, the pistons have a LOT of leverage against a soft valve coming in at an angle so that you just catch an edge. I was rotating the motor with a wrench the first time I replaced a cam chain, and bent 4 valves being VERY careful... and never felt a thing.