'81 750H - lost manifold bolt

Would also heat the stud and surrounding aluminum head area with a propane torch or heat gun just before extracting the stud. When heated, the aluminum head should expand more than the steel stud and thereby tend to loosen its grip on the stud. Careful not to burn yourself.

In any event, hot or cold, please wear goggles or glasses to protect your eyes from flying metal pieces (drimmel tool -- impact wrench -- drilling).

If dealing with a previously replaced stud, I've also heard that heat also weakens any residual locktite compound that might have been used earlier when the stud was installed.

I would not use any locktite when installing the new stud. Just my $.02.

Can't tell from the thread whether it's the inside or outside stud on #4 cylinder. Believe the outside stud is more accessible (being further from the frame downtube).

Am assuming all header pipes have been removed from the engine.

When finally reinstalling the header, be sure to use 4 new copper crush gaskets (also available from Z1E).

It can be a pain getting things lined up and started when the crush gaskets, flange holders and clamps keep falling out of place (reason for masking tape or rubber band holding the flanges in place around the header pipes to later burn off). Burning rubber really stinks if you forget to snip it off. :pinch:

Here's my easy fool-proof method that always seems to work just fine. Use a small screwdriver to gently clean the head groves where the crush washers fit. Use q-tip with acetone to finish the clean-up. Smear a little coating of hi-temp copper Permatex on the engine side of the crush washers and place them into the head. The Permatex will hold the gaskets in place during header installation and also help prevent any exhaust leaks. Just before installing the headpipes, smear a little more Permatex on the exterior side of the crush gaskets -- not really necessary but can't hurt. With the crush gaskets staying in place, it is far easier to manage the flanges and clamps -- and without needing masking tape or rubber bands. But if desired, masking tape might still help with the flanges.

I've never worried about which side of the new copper crush gasket went against the head and which side faced out against the header pipe. Recently learned from other more knowledgeable members that there is a correct way to do this, but can't remember which side faces in or out or why.

Hoping to hear of a successful repair.

Post edited by: Patton, at: 2007/03/20 18:18

Sadly very tight finances kept ordering of parts on hold until very recently. [Yeah, I know the bolt is only $2 but I wanted to make sure I got the crush gaskets, an impact driver, and (finally!) the Clymer manual.]

I am pleased to say that removing the bolt went without a hitch! Couple of squirts of PB Blaster (all that was available in these parts) and some patient 1/4 turns with a tight Vise-Grip and the bolt unscrewed without incident.

(Ironically, when loosening all the other bolts in preparation for properly seating all the pipes, a different bolt unscrewed from the manifold without trying! :laugh: )

Of course, nothing seems to go completely without complication. I was unable to remove the muffler sufficiently to install the new crush washers. When I bought the bike (a return to motorcycles after an over 10 year lapse), I didn't think much of the loud exhaust at first. Soon after the purchase, though, I noticed that the cross pipe had corroded and was behing held on by a bent clothes hanger. Eager just to get the thing running and assume its place as the "second car," I had the local shop do a bit of spot welding.

Looks like I won't be installing the washers until I can afford to replace the entire muffler.

But at least for now, my KZ750H no longer sounds like a hawg and it's amazing how much peppier it is with a properly sealed exhaust system!

Thanks for all your help!