realgasket damaged my camshaft tach drive??!!?

[ShirleySerious]

I'm having the same problem. I just got a new RealGasket for my '78 GS550 and now my tach is reading way lower than it should. I took out the gear and it looks OK; no chips, gouges or anything broken. Earlier today, though, it was making kind of a clicking noise. When I took it out tonight, the clicking was gone, but the tach still gave a bad reading.

I took off the cable and started up the bike. The notch seems to be spinning fine (although 'fine' is relative as I've never seen it operate with the cable off before). It's a brand new cable, so I can most likely rule that out as the culprit.

[Planecrazy]

I'm having the same problem. I just got a new RealGasket for my '78 GS550 and now my tach is reading way lower than it should. I took out the gear and it looks OK; no chips, gouges or anything broken. Earlier today, though, it was making kind of a clicking noise. When I took it out tonight, the clicking was gone, but the tach still gave a bad reading.

I took off the cable and started up the bike. The notch seems to be spinning fine (although 'fine' is relative as I've never seen it operate with the cable off before). It's a brand new cable, so I can most likely rule that out as the culprit.

Josh, I'm glad I saw this thread tonight. I suspect you have the thicker (and wrong) gasket because yours looked very thick to me. I didn't think too much about it because I didn't know that there was more than one choice for the bike. I would STRONGLY suggest that you NOT run the engine until you've contacted Realgaskets and verified that you have the thinner of the two gaskets ... I'm willing to bet that you have the thicker one, and you DON'T want to damage those gears if they haven't already been damaged! Make sure you tell them what's happening with the clicking and bad tach display - since they just heard the same story and sent a replacement to our fearless thread author, you shouldn't have any trouble getting them to do the same for you.

This would definitely seem to explain your "coincidental" tach problems. Let me know how it goes.

Regards,

[ShirleySerious]

I emailed Harold at RealGaskets to see if he knows anything about it. I'm awaiting his response. In the meantime, I'm itching to get back on the bike, so I came up with a novel idea so I can can ride without damaging any gears.

I cut my old broken tach cable and took off the part that screws on to the head of the valve cover. Then I gave it a thorough cleaning and sealed the end of it up with Form-a-gasket so oil won't leak out. I removed the tach gear and put the newly fashioned part on. I'm still waiting for the stuff to dry, so I might be getting ahead of myself. Hopefully this will work until I can figure out what the problem is. The downside, of course, is that the tach won't be functional, but that's not much of a problem, since I don't need to adjust the idle or anything, and I've seen bikes without tachs before.

[79-GS550-L]

You can also just remove the spiral gear and reattach the cable - the tach won't work but it will be oil-tight, and you don't need to seal up anything else.

You should take the valve cover off and inspect the splines on the exhaust camshaft (the raised edges that the spiral gear engages with). For me, and at least one other person, the splines were damaged but the spiral gear was still perfect. I think the spiral gear is made of a harder metal than the camshaft for some reason. If there is any damage to the camshaft, make sure you remove all slivers of metal, and sand down any sharp ridges with 200 grit sandpaper folded over a few times. It takes quite a while but it is necessary.

[posplayr]

83 GS1100E mangled Tach Gear

The PO pleaded ignorance, but from the thickness of the gasket I suspect that he knew he did it after having changed pulled the valve cover. If the gasket is too thick then the tach gear will skip across and eventually tear up the exhaust cam.

I have Cometic 24 bolt valve covers for the 1100E and it even is labled 0.047" (and measures out as well).

I also have a Athena full gasket set for the 81 GS750E and it mikes out almost exactly the same.

Poor design, bt we have to deal with it. a full 1/8 inch is 0.125" 3 three time as much thickness??? Wow that could really be a problem.

While in search of cams, I have now commited to new Webcams, APE springs, New spare head, new tach gear, new tach gear housing, with new followers as well as an overhead cam valve spring compressor(If I add it all up it is close to $1K and the whole bike only cost $1300).......whew all because of a cheap cam cover gasket. Be forewarned.

Posplayr

[catbed]

you say you tightened it down more and it started leaking oil. check your valve cover for cracks. i tightened mine down too much with a real gasket and it cracked the valve cover. got it fixed though.