Hello All. I am a complete newbie rebuilding the engine on my son's (now mine) 97 GS500e. The engine seized last summer and the mechanic said the pistons were fine and it was probably a top end issue due to an oil pump failure. I decided to tackle it on my own with the help of this board and the Haynes manual. I've made it all the way to separating the crankcase halves and finally found the root cause. Here is what I saw when I first removed the bottom half of the crankcase:



The nut fell off of one of the piston rods and both the nut and bolt, as well as the crankpin bearings fell into the crankcase and were wreaking havoc. My question is basically, based on the following images, what all do I need to replace to make this run again? I want to spend as little as possible, but don't want to skimp and cause a repeat failure down the road.

Here is the damaged Rod, which I know has to be replaced:



Does the crank shaft need to be replaced due to the discoloration, or can that just be cleaned off?





There is damage to the inside of both halves of the crank case. Here is the bottom half, with the plate in the bottom bent some, and the crankcase itself gashed:





Here is the top half, looking through the crankshaft. You can see a gash in the metal of the crankcase:





Do you think the crankcase needs to be replaced? Thanks for taking the time to read and I appreciate any advice you guys can offer.

--- Yuri

In my opinion, it would  be much easier and probably cheaper to buy a good running used motor. Loss like there's a lot of damage there, and the first pick looks like you will need to replace that side of the case, new bearings new crank at least one new rod. That's just my opinion though.

better safe than sorry... get a new crankcase

$60 on ebay

http://www.ebay.com/itm/1996-Suzuki-GS500F-GS-500F-engine-motor-crankcase-cases-/400674810360?pt=Motorcycles_Parts_Accessories&hash=item5d4a1469f8&vxp=mtr

Thanks guys! I appreciate the input.

I have 4 cases and internals except for spare crankshafts.

Let me know if you need cases and the gears, I'd be thrilled to get one out its getting tight in the garage parts pile
but that will be the least of your worries.

The crankshaft is most likely toast, apparently there are no oversize bearings so you cant have it shaved
down it needs to be welded and shaved to oem specs, like other mentioned, cost more than a spare engine
from ebay or from someone in this forum

Even i got enough parts to build a new engine, i rather buy them complete, look hard enough and you'll
find something for cheap in a few weeks 

if you need cases and other internals > text me 410 six89 5538

Thanks for the reply Illenium. I'll keep that in mind.

I have to agree I see mAJOR heat damage on crank. and who knows what else. used engines are plentiful. and usually decently priced
Aaron

Thanks yamahonkawazuki!

If you really want to, you could blow/clean all the metal shavings out, but then you would have to buy a new crank most likely, new rods, new bearings, possibly a new piston or two, new circ-clips, full gasket kit, new oil seals, and new rings all around most likely. That sounds like too much work and money when you could just buy a new used motor. However, I am all for the experience

agreed it is fun to learn. at MMI we used gs' for carb tuning experience. I fell in love with them then. tore apart an engine and rebuilt it. heres my advice. get a used engine in working order. silver preferably  for the bikes age. but really it doesn't matter. but 97 was I think first year of silver engine. and then once backj  on road, you can build this one up if you wish. and have a good spare.
Aaron

Quote from: yamahonkawazuki on April 01, 2014, 02:20:15 PM
agreed it is fun to learn. at MMI we used gs' for carb tuning experience. I fell in love with them then. tore apart an engine and rebuilt it. heres my advice. get a used engine in working order. silver preferably  for the bikes age. but really it doesn't matter. but 97 was I think first year of silver engine. and then once backj  on road, you can build this one up if you wish. and have a good spare.
Aaron

Thats some good advice right there, gets you back on 2 wheels and you still have the opportunity to tear the motor apart.

Thanks again for the advice guys. I really appreciate it. To be totally honest, now that I have the engine completely torn down anyway, I'm kind of leaning toward just finishing the job I started. At least that way once I am done I know exactly what I'm getting, whereas if I buy a used engine I have no idea what condition the internals are in. Also, time is not really an issue since I don't even have my endorsement yet. It's my son't bike, which he's already replaced. I'm just taking my time to get it done and I'll start riding whenever I can. Plus I'm having fun learning.

Isn't there some extra precaution you need to take though to make sure the bearings match the crankshaft or something if you replace the shaft? Also, does the year of the crankshaft matter or will they all fit? Thanks again.

have block checked for damage first

Will do! Thanks again!

I'd just buy used cases, one mechanic hour will cost more than that and you'll end up buying a new case anyway