1980 750t tac cable valve cover threads

Has anyone had success using a heli-coil to repair stripped threads in the valve cover that attached the tac cable?
Any info or other suggestions would be appreciated.

You've totally lost me.

The tach cable screws onto a fitting that presses into the head, it doesn't have anything to do with the cam/valve cover.

Can you describe your problem more precisely?

Sorry about that. I should have stated head. The threads (18 x 1.5mm are stripped). There is not enough material to re-thread. The only solution I can come up with is inserting a heli-coil. If anyone has an alternate fix, I'am open to suggestions.
Thanks,
bmac

Ok, now I understand!!

The tach cable has a 18mm external threaded bushing (cause I don't know what it's called) that screws into the head and holds the tach cable on, and is a never ending source of oil leaks.

I don't know if there is room there to drill and tap it for a Heli-coil/Timesert. That area is pretty thin.

If you don't have access to a good machinist and a machine shop, then a replacement head is probably the cheapest and easiest solution.

Steel, thanks for the info. I'll let you know if the heli-coil works.
Thanks again,
Rob

Will rely on steell to keep me out of trouble here :lol: , but based on the diagram from kawasaki.com (see below), am trying to better understand this thread by guessing :

#28 tach gear guide screws into the head via the "stripped" threads (because don't see what would otherwise hold the guide inside the head), but diagram doesn't show threads on the guide :huh: ;

#26 oil seal fits inside the guide where the #24 tach gear shaft fits through and spins (to prevent oil from escaping through the guide);

#25 0-ring or #27 tach gasket -- can't tell which -- prevents oil escaping around the guide between the guide and head, with the threads (being repaired) serving to both (a) hold the guide inside the head and (b) compress the #27 gasket or #25 0-ring.

For comparison, the KZ900 design uses a separate bolt to hold the tach guide inside the head (after guide with 0-ring around it pushes into the head).

After the thread repair, might it be feasible to use some Permatex high-temp thread sealant in this area?

Good Luck!

[Click on image to enlarge view]



REF NUMBER PART NUMBER DESCRIPTION QUANTITY US CA CN REMARKS


1 11022-008-2H COVER,CYLINDER HEAD 1 BARREL


2 11023-008 GASKET,CYL HEAD COVE 1


3 92003-092 BOLT,HEX HEAD,6X45 14


4 11002-5010 HEAD ASSY,CYL,BARREL 1 BARREL


5 92003-092 BOLT,HEX HEAD,6X45 16


6 92042-007 PIN-DOWEL 16


7 11004-1055 GASKET,CYLINDER HEAD 1


8 411B1000 WASHER PLAIN 10MM 8


9 92004-058 STUD,8MM 4


10 92015-076 NUT,CYLINDER HEAD 8


11 92055-095 "O" RING 4


12 92066-047 PLUG,CAM SHAFT 4


13 92066-052 PLUG,CYLINDER HEAD 4


14 92075-109 DAMPER RUBBER-CYL-HD 6


15 12013-007 GUIDE,INLET VALVE 2


16 12013-011 GUIDE,EXHAUST VALVE 2


17 92055-065 "O" RING,VALVE GUIDE 4


18 16065-036 HOLDER,CARBURETOR 2


19 220B0618 SCREW PAN HEAD 6X18 4


20 410B0600 WASHER PLAIN 6MM 4


21 92037-072 CLAMP-PIPE 2


22 92037-171 CLAMP 2


23 92059-122 TUBE,BALANCER 1


24 13223-013 GEAR,TACHOMETER 1


25 670B1510 "O"RING 10MM 1


26 92050-075 OIL SEAL 1


27 92065-103 GASKET,TACHOMETER GE 1


28 92087-009 GUIDE,TACHOMETER GEA 1

Not even close Patton

It's a 750 twin thing

To understand, you need to look at the tach "cable", not the head. The 750 twin has a large, well heck, I don't exactly know what to call it, so I'll try to describe it.

It looks like a large bolt that has a hole drilled through the center, the tach cable is in the center of the hole, the large bolt slides on the tach cable, it's threaded on the outside just like a bolt, and it screws into the head to lock the tach cable to the head.

Look at the right end of the last cable in this pic.






Oh yeah, that number 28 you were asking about? It is pressed into the head, you can use a screwdriver to press it out


.

Many thanks, steell!

It's a 750t thing is exactly right. The thread is a 18 x 1.5 mm. I drilled a hole in the bottom of a tap to fit over the tach shaft drive in the head. If there was enough material it would have worked. Next I tried JB weld to build up the thead area. The tap would not start straight.
I'am in the process of removing the head to try a heli-coil insert to solve the problem. If that doesn't work I will start looking for a replacment head.
Thanks
Bob Mc

I have a spare head or two for the 750 twin.

You can push the tach drive out from the inside, you just need to remove the cam/valve cover, and possibly the exhaust cam, to get access to it.