Hey guys I have a broken lower crankcase and was wondering what are my options for fixing it, I bought a lower crankcase to replace the broken one but after more research I found that they’re made as a set. Would I still be able to use the new lower part or could I possibly reweld the broken piece back together. Or should I just say forget it and buy a matching set somewhere. Any advice is greatly appreciated
-
Required reading for all forum users!!!
Welcome!
Register to access the full functionality of the GSResources forum. Until you register and activate your account you will not have full forum access, nor will you be able to post or reply to messages.A note to new registrants...
All new forum registrations must be activated via email before you have full access to the forum.A Special Note about Email accounts!
DO NOT SIGN UP USING hotmail, outlook, gmx, sbcglobal, att, bellsouth or email.com. They delete our forum signup emails.A note to old forum members...
I receive numerous requests from people who can no longer log in because their accounts were deleted. As mentioned in the forum FAQ, user accounts are deleted if you haven't logged in for the past 6 months. If you can't log in, then create a new forum account. If you don't get an error message, then check your email account for an activation message. If you get a message stating that the email address is already in use, then your account still exists so follow the instructions in the forum FAQ for resetting your password.Have you forgotten your password or have a new email address? Then read the forum FAQ for details on how to reset it.
Any email requests for "can't log in anymore" problems or "lost my password" problems will be deleted. Read the forum FAQ and follow the instructions there - that's what we have one for...
-
Returning Visitors
If you are a returning visitor who never received your confirmation email, then odds are your email provider is blockinig emails from our server. The only thing that can be done to get around this is you will have to try creating another forum account using an email address from another domain.
If you are a returning visitor to the forum and can't log in using your old forum name and password but used to be able to then chances are your account is deleted. Purges of the databases are done regularly. You will have to create a new forum account and you should be all set.
1981 GS650 E broken crankcase
- Thread starter ncint2
- Start date
If I find a crankcase set could I use all the internals I have already and just throw them in or is it actually better to find the complete engine. It was non running when I bought it for 100 dollars, it cranked and started for a couple seconds for a while but then just made a loud clank and it didn’t start anymore, I opened up the clutch cover and found part of the clutch basket was broken also, kinda bummed since I thought I had a mostly running motorcycle.
You need a matched set of cases. I suspect a good many of your internal parts are usable, but not all. You should focus on making sure you have the proper crankshaft bearing shells. I've never built a 650 so I'm not familiar, but no doubt, the factory service manual details out how to match bearings to crank.
As far as I know mine does not have crankshaft bearing shells, it has ball bearings and holes for the pins to lock in onto the crankcase. As for buying a new crankcase set, should I buy only gs650e or do gs550 or gs650 models also work, I know that the gs650 e is just the gs550 lower with gs650 upper half
From what you say, You got real big problems. to answer your question, yes all the inner parts should fit fine. Beware there are differences in the 650E and 650G engines. The loud "clank" and the broken clutch would point me to finding a complete eng., which is also a gamble.
Ah, E model. I missed that. So roller crank. Again, you need a matching set. No mix and match.
There is a 650E engine on eBay, in Ohio. Not horribly far away from IL. You can likely part out the spare parts and break even...
Or, there are a set of cases...in the UK. Price is cheap enough, and only $100 shipping. Worth a shot.
https://www.ebay.com/itm/402121422425
Or, there are a set of cases...in the UK. Price is cheap enough, and only $100 shipping. Worth a shot.
https://www.ebay.com/itm/402121422425
Last edited:
Yeah but unfortunately the previous owner tried to chop it up into a cafe racer, a bunch of bolts are stripped and the airbox was cut into pieces but for now I'm just trying to get a running engine and then deciding on what to do with it cosmetically,
KiwiAlfa156
Forum Mentor
I've used a set of unmatched cases before to build a GS engine, not considered ideal, due to the critical alignment of the cross-joint line boring of bearing journals. I had two sets of crash damaged 1100 cases with a good top and a good bottom case between them and thought 'what have I got to lose'? I'd heard that a local racer had replaced only the broken lower case on their GSX1100 race motor with success so I gave it a go. In my case (pun intended) the cases matched together perfectly with no alignment issues for either the crank or gear shafts, etc. In fact the engine ran well for many years until I sold the bike. Whether I was just lucky, or whether the automated line boring and machining processes accurately repeats during manufacturing to provide workable tolerances between unmatched cases, I do not know. But there is nothing wrong with testing the excepted truth, which sometimes is accepted because it is oft repeated.
