Getting started. 79 GS550 Street Tracker Rebuild

[Guest]

Hey there folks. So today is the official start of what I?ll call a slow process of rebuilding my 550 Street Tracker.
My engine stand came in so I have to make some adjustments to my workbench first, then put it all together. Hoping to get that done tonight.
So far, I have pulled the plugs and looked into the cylinders to find the #3 piston blown up (That explains my last ride).
So we?ll see where this takes me have to pull it completely apart and assess the situation.
Anyway, here are some pics before I get started.

Looks like I can only post one photo per post at this time. I?ll post more, later.

 

[Guest]

First obstacle completed. Got the bench down to the proper size and mounted the engine to the stand.
Next order of business is to try to figure out if I can save it. I blew a hole in the #3 piston. It figured out that this has actually been sitting for nearly 10 years. The head cover had been pulled off before going into storage. Unfortunately it wasn’t put back on beforehand. The garage it was stored in collapsed almost three years ago and it spent about 9 months in the elements.
That being said, there is a lot of corrosion on some of the engine. The camshafts have a tiny bit of surface rust. Have not cleaned them up yet. I’m really hoping I can save this engine and keep it from the scrap yard. I have no idea yet, where to start. If it weren’t in such rough shape, I’d he k the valve clearances first to get a baseline, but I’m not sure it would be accurate with the surface rust. Perhaps I can take some fine steel wool or brass wool to the cam lobes to clean them up and then check the clearances.

Either way, it’ll need to be torn apart to do anything.

What would you guys do? Where would you start?

 

[salty_monk]

Use Flickr or Imgur or something to upload pictures & then link the bulletin board

 

[Guest]

Use Flickr or Imgur or something to upload pictures & then link the bulletin board code :)[/QUOTE]

Nice! I totally forgot about that. So much easier to do it this way when using my "smart" phone.
Thanks for the advice! I have added a few pictures to my previous post.

 

[salty_monk]

The GS engine is very hardy, I'd be surprised if your engine couldn't be saved. I would say you have two options... the first it to clean it out & just get it running and go through a series of oil changes.

If it were me I'd pull the sump & look at the bottom end. If it looks good in there and shifts through all the gears I'd first get it running "as is" before attempting any kind of stripdown. Change the oil a few times in succession to clean it through.

You might need new rings & stem seals as plus some gaskets probably a worst case... obviously make sure it spins on the starter etc... Check the stator if you go behind that cover.

 

[Guest]

Thanks!
So essentially, pull the head off, change the piston and put it all back together to see if it?s running. inspect everything while it?s apart.
Any special considerations when changing that piston?

 

[JohnnyL]

Looks like a fun project! If you blew a hole in a piston, I wouldn?t attempt to get it running until you tear the engine apart and clear out any broken pieces. The last thing you want is loose pieces jumbling around inside the case. Just my two cents.

 

[Guest]

Looks like a fun project! If you blew a hole in a piston, I wouldn?t attempt to get it running until you tear the engine apart and clear out any broken pieces. The last thing you want is loose pieces jumbling around inside the case. Just my two cents.

I agree, the pieces of piston are in their somewhere. You may get lucky and the pieces went downward instead of bouncing around in the cylinder. Inspect the combustion chamber and cylinder walls for damage. Since you will be pulling the cylinder to remove the damaged piston, I'd replace all the rings and re-crosshatch the cylinder walls so the new rings can break in properly. The big question I would have is what happened to cause the damage?

 

[salty_monk]

Oops, sorry I missed the part with the holed piston.... Sorry about that.

In that case I'd go looking for pieces. Hopefully you can find them all without splitting the cases

You may find a better starting point from someone on here... but it might be fun to tear it down & see what you find first

 

[Guest]

Here it is

Here it is

So, last night I was able to pull the heads off and the cylinders. Got a real good look at everything.
Looks like I have some damage to the #3 cylinder wall. I’m wondering if it can be saved. Thoughts?





You can see the upper left part of the piston where those scuffs came from.



Here are the valves. #1 on top, #4 at the bottom. A lot of carbon build up on everything in there.



The other three pistons all look pretty much like this


Thoughts on what could have caused the blow-out?

 

[salty_monk]

Running lean I would think is the usual culprit...

You should be able to either get oversized pistons or pick up a better jug, I don't think you'll take that out with a hone. The head looks normal from the picture compared to others I've seen, the pistons shot looks pretty grubby but I've seen similar...

 

[JohnnyL]

By the amount of carbon buildup on #1, #2 and #4 valves and lack of carbon buildup on #3 valve, it looks like #3 was running pretty lean. But it is hard to tell from the photos. It just seems like there is a significant color difference on #3. What did the other spark plugs look like compared to #3?

So, last night I was able to pull the heads off and the cylinders. Got a real good look at everything.
Looks like I have some damage to the #3 cylinder wall. I?m wondering if it can be saved. Thoughts?





You can see the upper left part of the piston where those scuffs came from.



Here are the valves. #1 on top, #4 at the bottom. A lot of carbon build up on everything in there.



The other three pistons all look pretty much like this


Thoughts on what could have caused the blow-out?

 

[Redman]

Just following to see what happens with the engine rebuild.

.... and to see what "street tracker" might be.

 

[Big T]

A extra lean condition on #3 is probably caused by leaving the vacuum port open

Petcock may have failed, new Petcock, didn't cap the vacuum port. It wouldn't be the first person who had no idea what goes where

Find a decent 650 top end and use that.

 

[Guest]

A extra lean condition on #3 is probably caused by leaving the vacuum port open

Petcock may have failed, new Petcock, didn't cap the vacuum port. It wouldn't be the first person who had no idea what goes where

Find a decent 650 top end and use that.

Thanks for the input.
I don't think I'll be able to change the top end to a 650, but I had thought about that, but that would include replacing carbs, air cleaner, etc. Wasn't planning on that.

I'm not sure the pictures really show what the condition of the jugs are.
The scoring is pretty minimal, but I don't know exactly how deep honing would go. The scoring at the top, which is the worst, is at the very top of the jug. nowhere near where the ring reaches.
I'm wondering if I can hone out the rest of the jug, and if it'll still run fine.

Is it possible to change out just the sleeve of that jug?
What do I look for when trying to find a decent Head to replace this if I have to?

 

[Spyder]

It looks to me that the damage is at the very top of the cylinder. Can hurt to try and hone it out. Once to get all that sludge cleaned off of everything, you should be able to see what you really have. I can't see the whole cylinder though to tell definitely that it's good or not. You would not HAVE to change carbs, or anything else if you found a whole top end from a 650 of the same year. Pistons, jugs, head. That's it... I think they use the same carbs, but am not positive.

 

[salty_monk]

I would have thought at this stage it's worth at least trying to see if you can take it out with a hone.. You might find parts on here, otherwise Ebay

 

[Big T]

Yes, if that sleeve is toast, 20 minutes in the oven and it will slide out. The problem may be getting a replacement sleeve
But, hone it first and see what you have

 

[roeme]

That engine stand would be quite useful for my situation. By any chance you remember where you got it?

Also, subbed.

 

[Guest]

That engine stand would be quite useful for my situation. By any chance you remember where you got it?

Also, subbed.

As a matter of fact I do! I got mine on Amazon, but they?re available elsewhere.
Heres the link: K&L Supply MC25 Metric Engine Stand 37-9352 https://www.amazon.com/dp/B000GV3DSE/ref=cm_sw_r_cp_apip_wq9WXJ7hYmMnJ

Thanks for the sub!