Exhaust cam tach gear chewed up

[mark_vaughn]

The tach gear on the exhaust cam is chewed up and almost gone. This will likely lead to other problems inside the engine with all those shavings floating around, but that is another topic.

The question is concerning the tach. Shouldnt the cable side gear be brass? mine is steel, and obviously a harder steel than the cams.
I need to replace the cable anyway, I had to cut it off to remove the engine due to corrosion. Anyone know of a brass geared cable? Is OEM steel?



Not the best picture, but you get the idea.




And here is the tach side of the gears:

[Larry D]

Looks like the same metal my tach gear is made of. Don't know of a brass one.....

I've heard of this happening from the use of a realgasket on bike where the tach gear seats into the valve cover. The realgasket is thicker and therefore the gears don't line up correctly and the gears get chewed up. Was the valve cover gasket stock ?

[Dogma]

This is can be caused by using a silicone gasket such as from real gaskets, rather than paper. This messes up the spacing of the gears. A steel tach gear should not be a problem. A mating gear of sacrificial metal would only result in bits of sacrificial metal loose in the engine. Metal that the magnet in the oil drain plug can't attract.

If you're using the proper paper gasket, then something else is very wrong.

[mark_vaughn]

The engine hasn't run under my ownership yet. There is a paper gasket there.

What you are saying makes sense. Maybe a gasket was not used at some point in the past.

Should I replace the cam?

[TheCafeKid]

The engine hasn't run under my ownership yet. There is a paper gasket there.

What you are saying makes sense. Maybe a gasket was not used at some point in the past.

Should I replace the cam?

Id suggest you do if you can find a decent one. That MAY continue to spit metal bits, and your tach will likely be thrown off if it works at all.

[mark_vaughn]

Id suggest you do if you can find a decent one. That MAY continue to spit metal bits, and your tach will likely be thrown off if it works at all.

Thats what I was thinking. I saw one on ebay I will try to pickup.

Thanks.

[TheCafeKid]

MAKE SURE its off an 81 and NOT an 82 or 83!!! They were timed slightly different...

[posplayr]

Been there done that

I would suggest at least dropping your pan and cleaning the screen and wiping out any big chunks.

If you are anal, pop the clutch and look at the oil pump gears. I had "some" scoring inside the pump (which is before the filter). I replaced my pump, but you may be OK. That is just alot of metal. I think the Cometic specificy something like 0.047" thickness.

While you are at it get some slotted sprokets and degree the cams .

Jim

[SqDancerLynn1]

You could also do a custom instrument cluster with electronic tack

[mark_vaughn]

You could also do a custom instrument cluster with electronic tack

Havent thought of that, but it is a good idea. The rest of the cam is fine.

[mark_vaughn]

MAKE SURE its off an 81 and NOT an 82 or 83!!! They were timed slightly different...

Thanks. It is from an '82. So there goes that one.

I would suggest at least dropping your pan and cleaning the screen and wiping out any big chunks.

It looks like I will be going through this entire engine. Which should be fun. I have never played with motorcycle engines. The only part that I think will be significantly different is the transmission being in the same case. So we will see.

I can't turn it over with the starter yet, waiting on a tool to fix the clutch...

But I did connect a compression tester and turn it over with a wrench, I only got about 60psi... So unless the starter is able to double that I will probably need rings. Thus the engine gets completely torn apart and timing issues will follow...

If it wasn't challenging it probably wouldn't interest me...

[TheCafeKid]

Thanks. It is from an '82. So there goes that one.




It looks like I will be going through this entire engine. Which should be fun. I have never played with motorcycle engines. The only part that I think will be significantly different is the transmission being in the same case. So we will see.

I can't turn it over with the starter yet, waiting on a tool to fix the clutch...

But I did connect a compression tester and turn it over with a wrench, I only got about 60psi... So unless the starter is able to double that I will probably need rings. Thus the engine gets completely torn apart and timing issues will follow...

If it wasn't challenging it probably wouldn't interest me...

Dont be disheartened by your compression numbers yet. The test SHOULD be done when the motor is warm/hot with the throttle wide open. so you might be ok after all..

[posplayr]

All of the 16V 80-82 GS1100E and 16V 80-81 GS1100L cams are the same. Even the 80-81 GS750E 16V exhaust cam is the same part number as the above mentioned exhaust cams.

http://www.thegsresources.com/_forum/showthread.php?t=140749

[rapidray]

What Jim said! I love people that give advice NOT knowing what they are talking about. All of the cams will swap with each other. The differences are in the lift #s & if the exhaust cam has a tach drive gear or not. There is NOTHING that will keep you from swapping cams around! Did you read this Josh? If you want to offer someone advice, make SURE you know what you are talking about. Ray.