1983 GS1100E Camshaft Tach gear Advice

[posplayr]

I was pulling my newly acquired monster apart for inspection and investigation. I found another issue with the Tach.

http://www.posplayr.100megsfree3.com/gs750/gs1100E_speedo_gear.jpg

Should I replace this with a new cam and have to deal with the potential issues of line boring the cam towers on the head, or is it possible even if a little more expensive to weld and regrind the gear.

This would have least impact on the motor. With my new compression numbers, I suspect I have an 10.25:1 + overbore kit in the engine (compression is 180-205 cold) on an 49K miles engine. It looks like a stock cam but I'm not sure it was not reground.

Comments welcome.

Posplayr

[rapidray]

Unfortunately, you can't fix the gear. At least I have never heard of anyone being able to. I have LOTS of cams Jim. They all drop right in, you don't have to do anything to the journals in the head to make them fit. I have GS & GSXR cams. Call me again. Ray.

[Sunburn]

Seems like an easy way to go...

[posplayr]

OK another update on the cam situation:


THis is Intake 3 with a little pitting



This is Intake 2 with alot more pitting

And here is Intake #1: If you look closely you can see that the valve is barely following the cam profile. There is an abrupt jump in the wear pattern as if the vale is leaving the surface of the cam and then 30-40 degrees later it is coming back in contact. Does this look normal? I'm pretty sure the valves are not adjusted properly. I dont have the tools but they are on order. I was able to get a 0.007" feeler into Ext and Int #1; That is as far as I went. At this point, I'm looking to replace both cams with stock items.

Could this explain the low speed knock in the upper end? It had seemed to be coming from the left side of the engine.

Posplayr

[chef1366]

Looks like either that head was oil starved or a cam cap bolt was running amuck in there.
I would pull the oil pan and check the pick up screen and also the oil pump. I have a set of cams and an extra oil pan gasket if you need them.

[Nessism]

Those cams are junk, get some new ones or clean used. Followers are likely damaged as well.

Wear like that is not overly uncommon on bikes I've seen using rocker valve actuation. The wear on one side of the cam can be caused by uneven clearance side to side on the paired valves - rocker is forced to twist slightly.

Not sure the best way to check oil flow to the top end but you might have to figure out some way to varify.

Good luck.

[79-GS550-L]

my tach gear was damaged by using a gasket of incorrect thickness. I was able to repair it with some 400 grit sandpaper folder a few times and a lot of time & effort. It was pretty mangled, but I think yours looks worse. Also, you've got some other cam problems which sanding that gear won't help you with. But if anyone else has a mangled tach gear, yes it is possible to repair.

[rapidray]

my tach gear was damaged by using a gasket of incorrect thickness. I was able to repair it with some 400 grit sandpaper folder a few times and a lot of time & effort. It was pretty mangled, but I think yours looks worse. Also, you've got some other cam problems which sanding that gear won't help you with. But if anyone else has a mangled tach gear, yes it is possible to repair.

How are you going to put metal back on the gear on the cam?! That is one I would like to see! Ray.

[79-GS550-L]

How are you going to put metal back on the gear on the cam?! That is one I would like to see! Ray.

Well, I did not add any metal :-D. The realgasket I used was too thick, making the tach drive gear skip across the top of the cam gear. Without having really looked at it before, I'd guess maybe the top 1/3 of the gear was mangled, to the point where it had bits hanging over the grooves so the tach drive gear wouldn't mesh. I sanded away all the sharp edges and stuff hanging over, leaving the bottom 2/3 or so of the gear intact. With a thinner realgasket, the gears mesh just fine now. The OP's gear looks much worse than mine did, I was just noting that it is sometimes possible to fix the gear if you have enough of it left. I was pretty surprised that the camshaft gear got so bad while the replaceable tach drive gear stayed in perfect condition!

[Sunburn]

Posplayr,


:-D New cam's are in order so I guess that solves your Tach issue as well.


It would have sucked to get cams just becuase of the tach gear.

[posplayr]

Cams are off

Cams appear stock and a not much wear other than previously indicated. The cam lobes were well within the service limits.
He they are in all their glory:






Here are the insides of cam Towers




And here is a closeup of the worst cam lobe on #2 Intake with cooresponding follower. There is a little variation in wear on the follower but no ridges or groves.




Dropped the pan as well and found a spare peice of wire in the bottom (?????), there was a very fine dust/oil mixture in the bottom but no chunks. Will pull of the screen next.

Cams are on order from RapidRay; He is going to look for a 1984 GS1150 Intake with the 1983 GS1100 Exhaust (with tach gear).

Posplayr