Am I doomed???

[oshanac]

Recently after trying to pull my cylinder block off my engine (1979 GS 750) I broke a few (o.k. 4-5) cooling fins tips. I think it was the first time the block was off since new, I never had to pull so hard, and use my rubber mallet, etc. to make it come off. I'm in the middle of a full on restoration, so I have time on my side.

What are my options? I wouldn't mind going to a 850 conversion. If I buy the 1978-1979 850 block and heads, then I would have to go bigger carbs, the 850 cams and everything else. If I go that route, might as well go 1100 for the price.

I would love to fix it (or have it fiked if it isn't crazy expensive, read: over $150) or find a clean 2 valve 750 block. It seem rare to find them though. As soon as I see one, it's sold.

Anyone ever fix their fins and have it work (or not have it work-aside from the JB weld repair). I don't want to take any shortcuts, and will be restoring everything on the bike. If you have a 2-valve block you'd part with (and the fins are all there and intact) please let me know. Thank you all so much for your support!

[tkent02]

Recently after trying to pull my cylinder block off my engine (1979 GS 750) I broke a few (o.k. 4-5) cooling fins tips. I think it was the first time the block was off since new, I never had to pull so hard, and use my rubber mallet, etc. to make it come off. I'm in the middle of a full on restoration, so I have time on my side.

What are my options? I wouldn't mind going to a 850 conversion. If I buy the 1978-1979 850 block and heads, then I would have to go bigger carbs, the 850 cams and everything else. If I go that route, might as well go 1100 for the price.

I would love to fix it (or have it fiked if it isn't crazy expensive, read: over $150) or find a clean 2 valve 750 block. It seem rare to find them though. As soon as I see one, it's sold.

Anyone ever fix their fins and have it work (or not have it work-aside from the JB weld repair). I don't want to take any shortcuts, and will be restoring everything on the bike. If you have a 2-valve block you'd part with (and the fins are all there and intact) please let me know. Thank you all so much for your support!

Just get the 850 pistons and cylinders. The rest of the parts are the same. Use your old head, carbs, cams, all of it.
I have the 850 stuff if you want to go that way.

[chef1366]

Broken fins can be repaired or just don't worry about it.
Any pics of the damage?

[Nessism]

Broken fins can be repaired or just don't worry about it.
Any pics of the damage?

I tried to repair some broken fins but didn't do so well. Any tips? I found it easier to just buy a clean used cylinder/head off ebay.

[chef1366]

APE does the work. I showed them my cylinder and they said not to worry about it and it was cosmetic. If alot of fins are broken near the surface this could effect cooling.

[oshanac]

Thank you for the responces. I think by looking at it, its cosmetic. But that's what I am worried about. I'm going to be fixing, polishing, painting everything-jut the thought of a half-assed job gives me nightmares. I'll ask APE how much it is to fix. I wish the sold the blocks for the 750's. They sure look sweet.

tkent02-Do you know if there has to be jet size increases for the carbs for the cc' upgrade? Have you done this yet to a 750? Just curious. It's easier hearing what worked from someone else instead of reinventing the wheel. PM me what you are looking for the 850 pisons/block. I'm interested (are they the two valve 850 parts?)thanks.

[oshanac]

"I tried to repair some broken fins but didn't do so well. Any tips? I found it easier to just buy a clean used cylinder/head off ebay. "-that's what I'm affraid of. I can't find any 1978-1979 two valve block's out there. The cylinder head is fine thankfully. Thanks for the input though!

[Nessism]

There are several cylinders on ebay right now, with various prices. Try searching on "GS750 cylinder". You can also use a GS850 cylinder and pistons if you want a displacement boost.

[tkent02]

I offered an 850 cylinder and pistons a few posts back, do you want them?

[oshanac]

Wow, yesturday I must have not typed cylinder block correctly or something on Ebay. I saw quite a few tonight. I am still interested in the 850 stuff though tkent02.

[TheCafeKid]

Wow, yesturday I must have not typed cylinder block correctly or something on Ebay. I saw quite a few tonight. I am still interested in the 850 stuff though tkent02.

I would also suggest getting Toms stuff, you only need the pistons, pins and the jugs. The carbs you have will need some SMALL tweeks, but I dont think they were jetted any larger...dbl check me on that. If so, its only likely a main jet bump of one or two sizes at most. The boost is basicly a big bore kit, without the compression change. TOTALLY worth it.

[oshanac]

Awesome Cafekid. I'll try to work out a deal with him.

[mac65]

Hey hows it going just wanted to put my .02 in I done the 850 cyl upgrade this spring stock pipes k&n filter in stock box no jetting required bike ran great at about 1.5 turns on idle air adj ---best of luck Mac

[oshanac]

That's exactly what I needed to here Mac65. Can you confirm you only need the pistons (with rings of course), cylinder block, and pins? THank you SO MUCH for your input. Even though it's short, it gives me A LOT OF HOPE for the conversion! Noticable difference in power? The 1979 GS 750 is a beast as far as 750's go. This is my third GS, and second 79' 750.

[oshanac]

tkent02-you have IM sir.