Hey everyone,
     I bought my first motorcycle, an 89' GS500 about a month ago with engine problems, but it was so cheap I decided I'd ride it until it dies and then upgrade. To make a long story short, I blew the engine, and for about 2 weeks now I've had an ever increasing itch to ride.
     Yesterday I made a 12 hour drive down to Tennessee to pick up a used engine for $125. I wasn't expecting much for the price, but other than the fact that it's sat for a year, it seems in pretty good nick. I want to try to start it, but what should I be cautious about trying to start an engine that has sat in a garage for a year?

What I've done so far:
Teaspoon of oil in the spark plug holes
Transferred my old (good) stator to the new engine
Transferred the timing components to the new engine (the bad ones were spray painted black!)

That's it. I degreased the whole thing and I'm working on getting a stuck/bent bolt out of the exhaust manifold. If anyone wants pictures I've got a lot.

Clean the carbs,adjust the valves,change the oil and filter,spin it with the spark plugs out to be sure it's spinning freely.

What are the compression figures like?

Checking them now while its on the bench could save you a lot of time and effort if they turn out to be bad.

I got the bad exhaust bolt out, how it was bent at the first 1/4" is beyond me.

Measuring the  valve shims gives me .245mm which doesn't quite make sense to me. Is it possible for the gap to be that big? The pickup was turned to the r-t position and my camshaft marks are lined up properly.

As for compression, should I just put the top back on, pull out a plug and spin it with the wrench?

I found another problem.
I should've guessed that because all of the electronic wires had been cut (even the clutch cable), there would be problems internally. I worked up the shims/buckets to the tightest fit that I could, and then I go on to the stator side to check it out. The p/o told me the stator was there, but wasn't sure of it's condition. I open it up, and find out that the magnets from the alternator had been removed (with a hammer I'm guessing), the stator was missing, and the bolt for the alternator had been WELDED to the crank. I'm still fuming, no doubt about it I'm demanding a refund for the cost of the stator.

I got it off!

I can't seem to get the one from the good engine off though. Any good tips for a stuck bolt?

I would run far away from that engine.It's done if the rotor bolt is stuck.

I got everything worked out, and mounted up. I finished re-building my carbs and popped in a new air filter too.
I'm waiting on some valve shims to adjust the clearance, would it be ill-advised to try and start the bike?

Quote from: Dizzledan on August 07, 2011, 08:13:17 AM
I got everything worked out, and mounted up. I finished re-building my carbs and popped in a new air filter too.
I'm waiting on some valve shims to adjust the clearance, would it be ill-advised to try and start the bike?

If you have shims in,it may start but will probably run rough until the valve clearances are in spec.CV carbs are very sensitive to vacuum and the valves being out of spec will cause running issues.

Gotcha, thanks for the replies.

Shims came in today, so my valve clearances are in spec. I was so excited to try and start it up (as I haven't ridden in nearly 3 weeks), but she wont start. I've got fuel on the spark plugs (which are sparking) and no compression. This is very bad news I take it?

Recheck you valve clearances.

I'm about to give up! 
I just did again, they're way off! The left exhaust is at .154 right exhaust is at .0386. I ordered the shims according to the excel calculator sheet thing, the math worked out to what I ordered. Nothing is sitting flush with the cams, but I still have no compression (0 registered, finger still sits on the hole w/o being blown off). The only thing it's doing now is backfiring nearly every time I try to start it.

Anyone in Central Ohio want to swing by to take a look at this thing and help me out? I'm a chef so I could cook you dinner or something...

Quote from: Dizzledan on August 08, 2011, 03:07:58 PM
I'm about to give up! 
I just did again, they're way off! The left exhaust is at .154 right exhaust is at .0386. I ordered the shims according to the excel calculator sheet thing, the math worked out to what I ordered. Nothing is sitting flush with the cams, but I still have no compression (0 registered, finger still sits on the hole w/o being blown off). The only thing it's doing now is backfiring nearly every time I try to start it.

Anyone in Central Ohio want to swing by to take a look at this thing and help me out? I'm a chef so I could cook you dinner or something...

Use should use metric feeler gauges.It works way better than fractional inch feelers.I tried and failed.The math used to determin the correct shim is easier when you use metric feelers.It's more accurate.
http://video.google.com/videoplay?docid=-2015554469142545363

Haha I'm realizing that more and more, need to pick up a set. I had an epiphany last night I wanted to ask you Ben; If my shim math (and patience) doesn't work out, my next route would be to transfer the head and pistons from the old engine and put them on this used one. Assuming the shims aren't my compression issue, it would have to be the pistons/head clearance correct?

Quote from: Dizzledan on August 09, 2011, 11:53:22 AM
Haha I'm realizing that more and more, need to pick up a set. I had an epiphany last night I wanted to ask you Ben; If my shim math (and patience) doesn't work out, my next route would be to transfer the head and pistons from the old engine and put them on this used one. Assuming the shims aren't my compression issue, it would have to be the pistons/head clearance correct?

Loss of compression is due to a few issues.The piston to head clearance is what it is and is set by the design of the engine.The main things that cause a loss of compression are:valve clearances to tight,valve or valves seats damaged or cracked,piston rings seized or not sealing against the cylinder wall,scored or cracked cylinder,cracked or burnt piston.These are what are reported.Usually it's valve clearance being to tight,a damaged valve or seat,and some times bad rings or cylinder.I wouldn't do any parts changing until I did a full compression check with a gauge and see where the issue might be.

This is a good read on doing compression tests. http://www.imperialclub.com/Repair/Engine/tests.htm

Subscribed to find out what happens! I'm in awe of your patience, Dizzledan. 

Quote from: ben2go on August 09, 2011, 12:16:19 PM.I wouldn't do any parts changing until I did a full compression check with a gauge and see where the issue might be

I agree fully, any used engine with an unknown history should be compression tested before even considering using it but your first suggestion to the OP was to throw time and money at it and clean the carbs, check the valves, and change the plugs and oil!!

Lets hope the problem is related to valve clearance and not something more serious like a holed pistion or something similar eh?

Another newbie gets dubious advice............If you were my mechanic I would have fired you off a long time ago 

Quote from: sledge on August 10, 2011, 09:29:08 PM

Quote from: ben2go on August 09, 2011, 12:16:19 PM.I wouldn't do any parts changing until I did a full compression check with a gauge and see where the issue might be

I agree fully, any used engine with an unknown history should be compression tested before even considering using it but your first suggestion to the OP was to throw time and money at it and clean the carbs, check the valves, and change the plugs and oil!!

Lets hope the problem is related to valve clearance and not something more serious like a holed pistion or something similar eh?

Another newbie gets dubious advice............If you were my mechanic I would have fired you off a long time ago 

Yeah,I was kind backwards on that but I assumed......

Quote from: sledge on August 10, 2011, 09:29:08 PM

Another newbie gets dubious advice............

To be fair it was the only advice I'd gotten, and I needed to clean my carbs anyway

As of this point, I've reset the timing again, pulled the engine, and brought it to a local Iron Pony mechanic for compression tests as per the general consensus recommendations. Honestly though, I feel like I've gotten everything for a steal so far. The bike only cost $300 (and I got 500 miles from the original engine), used engine cost more than the bike did ($315 w/ transport). It's going to be hard to justify a $500 repair bill.

Pandy: Thanks. It's so hard wrenching in my garage and hearing the sportbikes and crusiers zooming by knowing I cant go out and join them in this beautiful weather. 

In the meantime though, I get to upload some of the pictures!

This is the original engine that had 14,024 miles. I think this is the crankshaft output (which goes to the sprocket?) on the stator side. When it went, I was riding it with a fairly loud knock beforehand and it got even stronger.

This is the front of the bottom block with a special non-factory oil dispenser:

Remnants of the spent bearing:

What came out in the oil   


Lets hope I never have to adjust the forks:


After I cleaned my carbs and put in new jets:

Does the head diameter matter? The new ones are significantly smaller, though the threads are identical. I ordered these from Cape Fear Motorsports listed as Mikuni Main Jet - 127.5. I only changed the main jets because I knew they had never been changed, yet a Vance and Hines SS exhaust was put on. Should I change the other jets as well or do I only need the main jet?

As she sits more patient than I: