Im stumped, im working on a 71 cb350 twin project and completely disassembled the engine down to the cases to fix a bent valve and replace the rings and cam chain tensioner. Everything came apart except; I left the crank shaft assembly together and left the transmission shaft/gear assemblies together. Cleaned everything, re-assembled with new gaskets, seals, rings, cam chain, new oem cam chain tensioner, and cam chain slide.
Put it all together and it ran fantastic. I then drained the oil to look for signs of trouble and sure enough there is aluminum in the oil. Mostly very small debris, the size of finely ground pepper with the occasional flake or stringer sized piece. I started to disassemble, i didnt notice any of it making it back up into the oil filter or into the oil pump, though im sure some of the very small particles did because they were in suspension in the oil. Took the top end off and didnt see any debris on the bottom of the cam case under the rocker arms.
After the first rebuild i did not remember correctly installing the cam chain tensioner....i did NOT re-adjust it per the manual when i installed it, just bolted it down.
I proceeded to take everything apart, split the cases, and looked everywhere for signs of wear. The only thing i found was scoring on the side of the cam tunnel between the cylinders on both sides. I looked like the cam chain could have been flexing and potentially rubbing on either side. I thoroughly inspected everything and didnt see anything else that looked out of the ordinary.
I build the motor back up with a new gasket set figuring the cam chain was the culprit. I installed the cam chain tensioner per the clymer manual put it back in the bike. It fired right up, runs great! I let it run for 10 minutes or so, drained the oil, and there is more debris......shit.
So now i am at a loss, im fairly confident that the cam chain is still the issue, the debris in the oil looks the same as the first time around. I saw absolutely no other signs of wear any..wear...
Has anyone ran into something similar? Would it be a good idea to somewhat over tension the cam chain? I could bolt the tensioner part of the way down, then tighten the locking screw, then install it all of the way. Any help? thanks.
Put it all together and it ran fantastic. I then drained the oil to look for signs of trouble and sure enough there is aluminum in the oil. Mostly very small debris, the size of finely ground pepper with the occasional flake or stringer sized piece. I started to disassemble, i didnt notice any of it making it back up into the oil filter or into the oil pump, though im sure some of the very small particles did because they were in suspension in the oil. Took the top end off and didnt see any debris on the bottom of the cam case under the rocker arms.
After the first rebuild i did not remember correctly installing the cam chain tensioner....i did NOT re-adjust it per the manual when i installed it, just bolted it down.
I proceeded to take everything apart, split the cases, and looked everywhere for signs of wear. The only thing i found was scoring on the side of the cam tunnel between the cylinders on both sides. I looked like the cam chain could have been flexing and potentially rubbing on either side. I thoroughly inspected everything and didnt see anything else that looked out of the ordinary.
I build the motor back up with a new gasket set figuring the cam chain was the culprit. I installed the cam chain tensioner per the clymer manual put it back in the bike. It fired right up, runs great! I let it run for 10 minutes or so, drained the oil, and there is more debris......shit.
So now i am at a loss, im fairly confident that the cam chain is still the issue, the debris in the oil looks the same as the first time around. I saw absolutely no other signs of wear any..wear...
Has anyone ran into something similar? Would it be a good idea to somewhat over tension the cam chain? I could bolt the tensioner part of the way down, then tighten the locking screw, then install it all of the way. Any help? thanks.
