Please help! 1981 GS450L cam caps binding

[GregT]

Pull the head and strip it - mount up the cam bearing caps and take it to a good engineering shop. They should be able to hone the bearing bores to the correct clearance. They should also be able to tell you if it's still flat on the head gasket face.

[hillsy]

Are you absolutely positive you have the caps in the right spots? Maybe try tightening the caps with the cams out to see if you can see / feel any mis-matching of the bores. Or swap them around and see if they have clearance in the other positions.

By the way - was the motor running OK before you pulled it down? No chance you could have use caps off another (spare) head?

[osterizer03]

Yeah this was a running motor and all of the caps are in their correct ABCD order. I'm pretty sure my problem is that 3M bristle tool I used. My new (old) head comes in today so I'll go and rebuild that one without that bristle tool. What's the best way to remove old baked on gaskets from motors? I don't want to use a razor because you always seem to scratch or gouge something.

[1980GS1000E]

My guess is that you are overtightening the caps. Check your torque wrench. The caps don't have to be very tight at all.

[posplayr]

Yeah this was a running motor and all of the caps are in their correct ABCD order. I'm pretty sure my problem is that 3M bristle tool I used. My new (old) head comes in today so I'll go and rebuild that one without that bristle tool. What's the best way to remove old baked on gaskets from motors? I don't want to use a razor because you always seem to scratch or gouge something.

I have even filed the valve cover and head surfaces on to get them flat, but I did not do it with the cam caps removed. I guess we don't really know how much material you removed. I would still take it to a shop of find a new head.

[Gun-Nut]

I dont know much on bike engines. But as a machinist and have built several V8 350's. I would get a set of bore mic's and with the cams removed torque the caps down and get a reading for all 4. Then mic. the cam. see if ya might have the cams backwards or the intake and exhaust cams in the wrong sides.

[posplayr]

I dont know much on bike engines. But as a machinist and have built several V8 350's. I would get a set of bore mic's and with the cams removed torque the caps down and get a reading for all 4. Then mic. the cam. see if ya might have the cams backwards or the intake and exhaust cams in the wrong sides.

I think that is why we keep telling him to take it to somebody that can figure out the issue.

[osterizer03]

I took pictures of each part of the motor while I disassembled it and i know everything is in their correct orientation. This thing is pretty simple not to mix up parts. The problem is I don't want to pay through the nose to have a shop tell me what I already probably know. I don't have enough clearance in between the caps. I just received my new head in the mail and checked the clearances on that one and torqued the caps down. The original head would have a line of no plastic in the middle of the plastic strip which means that there is no clearance between the cams and the caps. Now on this new head, there are all measurable plastigage strips and after I cleaned the plastigage off, and re oiled everything, I put them back together, and the cams spin nice and freely. So I'm now in the process of tearing down this new head and do some mods to a couple fins to fit my exhaust (2 into 1 pipes I made), clean old gaskets off, baking soda blast, lap valves, and re - enamel paint. Hopefully within the next couple weeks I'll have the new head in. I'll keep you guys posted

[posplayr]

Well is the head warped or is it the custom cap tuning?

[blowerbike]

with the head off and the valves removed install one cap at a time till you find the one or more binding then take a ball hone and go to work with the cap torqued until the cam will turn with ease.
this is also done on larger HP engine to free up a little HP.
you didn't remove enough material with the 3M(i use a used red) to cause your problem and a razor won't do any damage either.
i have used both of these my entire life without a problem.