Bummed out.

i almost completed my 82 750e cafe build when i was changing the spark plugs when i noticed cylinder #3 threads were trashed. now what? pull the head and take it to a machine shop?im not so happy. i also have a second question which im sure has been asked a millions times before. could i put a 750 gpz head on my 750e?if so are there any concerns other then air/fuel and what years are compatible?im looking to possibly do a rebuild or big bore now if im cracking the engine apart. theres no good way to tap or rethread the spark plugs hole with the head on right?thanks

Cross-threaded or completely stripped bare of thread?

Where thread remains, but impossible to get the plug " started" into the hole, the threads may sometimes be restored by using a "back tap" (also known as a "reverse tap") tool to re-cut the damaged portion of the thread.

A back-tap tool begins the re-tap at the deep end of the spark plug hole where the thread often remains okay.

Once started, the re-threading progresses upward and on through the cross-threaded upper part of the hole. Thereby restoring and re-aligning the threads.

Such tool may be used without removing the head, or any other dis-assembly.





Good Fortune!

I have heard a product called HELICOIL works wonders. it is actually what looks like a threaded bushing. the threads on the outside are tapered so that as you screw it in they get tighter and tighter...the threads on the inside will be the original size of the hole that stripped.

I've installed helicoil inserts into stripped out spark plug holes without removing the head. I put the piston at TDC and use a lot of grease on the tap to catch the metal particles. After the repair I tape a straw to a shop vac and stick into the spark plug to remove the remainder of whatever fell into the hole.

thanks for the advise everyone. i will let you know what i decided. im moving the bike on a trailer in a few days so i may decide swing it by a local shop to see what they have to say about it. anyone know anything running a gpz or a more aggressive cylinder head on my 82 750e?

Another repair to look at:
www.cyclemadness.com/cmforum/index.php?topic=76.0
www.timesert.com/

Yes you can use a GPz750 head on your 750E, direct bolt on.

May be worth 1-4 hp.