CB350 motor won't turn over by hand

Danny Provolone

New Member
First let me say that I know it's shitty to be asking questions on a first post, and I'm prepared to take the heat for that. I'm really hoping someone can over look that and give me some advice in order to get my bike back together and on the road.
The lame introduction: My name is Dan, I live outside Dallas,TX, originally from New England. I forget words when I type(even after proof reading...sorry in advance). I picked up a 71 CB350 about a year go. Ran great, low miles(supposedly) so I didn't do much. Just fork seals, new exhaust, oil change and filter clean, set of plugs and on my I went. I've been hanging out reading post for a few months now(sorta watching and learning) this place is a wealth of knowledge.
So here is my issue. Two months ago the left side coil died. After pulling the tank and coil I saw that I had decent oil leaks from the cylinder and head gaskets as well as the cam box gasket. I ordered up a full gasket set, KA cam tensioner(I figured while it was apart I might as well), and a top end bolts kit. Got everything broken down and cleaned with no major issues, clearanced the head to fit the slipper, plenty of room now. I ordered but did not change the cam chain(it looked mint with no noticeable wear) I may regret that later, I know. So I get everything back together following the original honda manual, the issue I'm having is that when I try to turn the motor over by hand(using the bolt on the generator), it gets about half a rotation and then stops. I can see through the spark plug holes that both pistons more freely, and all 4 valves appear to be free as well. If I break the head bolts loose and take the cam box cover off I am able to turn it over no problem(although the cylinder tries to lift from the crank case). If I put the cam box cover back on and re-torque the head bolts, the issue comes back. Half a rotation and then it stops.
I have searched this forum and other sites, but can't find anything. Hell, I'm not even sure what I should be searching for.
Any help/advice/shit talking that leads to advice, would be greatly appreciated. I just want to get back on the road.

D
 
Sounds like you cam timing is off and a valve is hitting a piston. Haven't work on a CB 350 in a minute to tell you which timing marks to use. Go over setting up the cam timing again.
 
dnhnky said:
Sounds like you cam timing is off and a valve is hitting a piston. Haven't work on a CB 350 in a minute to tell you which timing marks to use. Go over setting up the cam timing again.


thanks man, i'll take another look at cam timing. I assume you mean the three sets of marks on the stator, cam shaft, and cam sprocket?
 
Yeah your cam is incorrectly timed

Hopefully you stopped when you felt resistance and didn force it enough to bend a valve.

You want to put the little nub on the advancer side of the cam at 12 o clock. Then you should have the line on the cam sprocket perfectly in line with the top of the cam case.
F0943426-44BB-44E2-9135-2791A0A681C1-6367-0000036C783AB13E.jpg
 
SONICJK said:
Yeah your cam is incorrectly timed

Hopefully you stopped when you felt resistance and didn force it enough to bend a valve.

You want to put the little nub on the advancer side of the cam at 12 o clock. Then you should have the line on the cam sprocket perfectly in line with the top of the cam case.
F0943426-44BB-44E2-9135-2791A0A681C1-6367-0000036C783AB13E.jpg

Thank you. Yea, I didn't push it to hard, I stopped to take it apart again. I will definitely take another look, but I think you are right, I miss timed it. The picture is super helpful.
 
The picture was taken to remind me which screw goes where haha. But it gives you a good visual on how to line up the cam.
 
Your timing is off. Don't force it over or you will bend your valves. Just happened to me a few weeks ago. Shitty situation all together. Take the cam gear off and move the chain until the piston reads TDC and your cam is lined up per manual specs.


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Took everything back apart last night and as expected, you guys were correct. Timing was off. Got everything lined back and put back together and she turns over perfectly.

Thanks again guys!!
 
"You want to put the little nub on the advancer side of the cam at 12 o clock. Then you should have the line on the cam sprocket perfectly in line with the top of the cam case. "

What is the "little nub on the advancer side"? I have this same problem and was relieved to see someone else have it, and someone have the solution. I just don't understand what you mean by "little nub on the advancer side". Thanks
 
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