Scratches inside cylinder head
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Scratches inside cylinder head
Hello all. I've got the top end of my 1979 GS850 apart right now. I noticed yesterday that just above where #2 intake valve and springs sits there's some scratches in the cylinder head casing. I didn't really know what to think about it, other than, someone else, at some point, has taken this top end apart. The PO is a friend of mine and he says he hadn't opened up the engine at all, so had to be someone prior to him. I don't think this had any negative impact on how the bike ran, but I wanted to see what you all had to say about it.
Ryan
1979 GS850G - currently undergoing a major overhaul
1986 GSX-R750 - I'm figuring it outTags: None -
Something like that, yeah. I'm having trouble picturing exactly what they were trying to do, but the mind of the PO is a terrible, strange place I do not understand. But that sure looks like human error. Maybe some weird accident with a homemade valve spring compressor. Maybe they shattered a shim trying to get it out with a screwdriver or something, and a piece bounced around in there.
Same. Are the other journals OK? What does the cap on that journal look like? What does that surface on the camshaft look like?
The damage around the valve bucket well is pretty much irrelevant.1983 GS850G, Cosmos Blue.
2005 KLR685, Aztec Pink - Turd II.3, the ReReReTurdening
2015 Yamaha FJ-09, Magma Red Power Corrupts...
Eat more venison.
Please provide details. The GSR Hive Mind is nearly omniscient, but not yet clairvoyant.
Celeriter equita, converteque saepe.
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Co-host of "The Riding Obsession" sport-touring motorcycling podcast at tro.bike!Comment
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If the cam journal shown checks out as far as wear, except for that damage, and the cap is ok, then that would work fine. Check the clearance.Current Rides: 1980 Suzuki GS1000ET, 2006 H-D Fatboy, 2021 BMW K1600BComment
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Here's pics of each journal, and the cap in question. They all look fine to me but you guys would know better.




Ryan
1979 GS850G - currently undergoing a major overhaul
1986 GSX-R750 - I'm figuring it outComment
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Thank you 1980GS1000E. The engine ran pretty well prior to disassembling, so I'm under the impression the scratches were of no significance but, of course, I wanted to get a consensus from the group.Ryan
1979 GS850G - currently undergoing a major overhaul
1986 GSX-R750 - I'm figuring it outComment
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Oofah. Some scoring on the cam journals. If you can feel the scratches with a fingernail, you have problems. If you can't, just buff them a little by hand with a Scotchbrite pad.
Mad83 GS750E
2006 ZX14
2004 KTM 450 EXC
2001 Yamaha Big BearComment
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Thanks Mad. Just went over all of the journals with a fingernail, smooth as a babies bottom. It's my understanding that there's gonna be some scoring, and that this amount is completely normal.
With respect, wouldn't a Scotch-Brite pad scratch up the surface?Last edited by RustyTank; 01-24-2021, 06:58 PM.Ryan
1979 GS850G - currently undergoing a major overhaul
1986 GSX-R750 - I'm figuring it outComment
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Last edited by RustyTank; 01-24-2021, 05:40 PM.Ryan
1979 GS850G - currently undergoing a major overhaul
1986 GSX-R750 - I'm figuring it outComment
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