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Piston seized, Pics inside, what do you think?

Discussion in 'The Garage' started by Rexxis, Aug 28, 2011.

  1. Rexxis

    Rexxis Almost there...

    PO told me that the engine kicked over and felt fine but stupidly I never tried to kick it over until today. What do you guys think I should do?

    My plans as of right now are to take the cylinders and pistons in to the cycle shop on tues, hopefully I can get away with a honing and new rings for both pistons. Hopefully I wont need to have the cylinders bored.

  2. azman857

    azman857 '80 XS 650SG Rider XS650.com Supporter Top Contributor

    Save up for the machining and new oversize pistons and rings. Maybe Mikes 750 kit with new bigger cylinder assembly. Top it off with a mild porting. Assemble and FLY down the hiway. I was in your shoes with a KZ 650 engine. By the time you get the cylinders smooth it's too big for stock pistons.
  3. xjwmx

    xjwmx It's just the unknown. Top Contributor

    People have resleeved the cylinders pretty often. I think I remember reading if you put it in the oven the sleeves fall right out? Wait for confirmation here before you try it. I think ggggGary dddid it.
  4. sgallaty

    sgallaty Antihero

    That actually does not look terrible to me.

    Give the jugs a quick dunk in phosphoric acid solution (10:1 or so), you'll find it at home depot. That'll take the rust away then you can see what you've got to deal with.

    when you take it out of the phosphoric acid (which is mild, but still - wear gloves and eye protection and use good ventilation) you'll want to wipe off the ferrous bits with paper towels and then wipe it down with grease or oil to prevent flash rusting.

    what you should be concerned about is pitting on the surfaces that the rings contact.
  5. You can sweat out the cylinder liners in a normal stove at around 400F. I saw a liner being pressed out cold in a picture on the 650motorcycles site. If you get a stock liner installed, you might get away with boring one liner and getting a new set of rings once the pistons are cleaned up. Alternately, you might just bore out both cylinders to an appropriate oversize and get new pistons. There are several ways to attack this problem.

    Mikes XS has liners for stock size pistons. I think the also have a complete stock block.
  6. Rexxis

    Rexxis Almost there...

    :Ok gallaty, thank you for the advice. I'll probably do that tomorrow. I'll post pics and we can go from there.

    Thanks bigtime!:thumbsup:
  7. gggGary

    gggGary Stop that! XS650.com Supporter Top Contributor

    Yeah what he said, but don't get your hopes up, that looks beyond a hone job to me.

    I am guilty of cold pressing out a liner but only because I did not research here first to find out oven heating is the answer and it didn't matter to me because the engine was beyond hope, I just wanted to lighten it for use as on mock ups.
    I have enough parts that I might be tempted to try replacing a bad liner with a good used one some day. Plenty of stuck motors, often just one side is rusted. Or the motor dropped a valve and one side has a good piston and liner.
  8. 650Skull

    650Skull SSSSSSSSSlither Top Contributor

    If your bores have to be bored out or especially replaced then at $392.00 for liners and pistons from Mikes, (Have to get the liners in and out which you can do yourself), you still have to pay to get them bored for the new pistons + buy a gasket set.

    It would be cheaper and a lot quicker to buy Mikes 650 kit or pay a bit more for the mikes 750.
  9. you will not likely need sleeves. Clean up the rust with kerosene or diesel and pass a three stone hone through it. In only a pass or two you will know if you need a re-bore. If you do, get oversize pistons and take them and the cylinders to a machine shop with the clearance specs. a bike shop will cost you double...IMHO
  10. Rexxis

    Rexxis Almost there...

    Good info mouser. That's my plan as of right now.
    Thanks everyone.
  11. sgallaty

    sgallaty Antihero

    he needs to remove the rust before attempting to hone or bore, the rust is an abrasive and will come off and abrade it further.

    phosphoric acid -> observation -> take steps as required

    I agree with mouser that the steps are probably a flex hone - but that'll depend on how much material you've lost and if you have a bad horizontal ring where the piston sat.
  12. Dakota_Lew

    Dakota_Lew XS650 Agronomist

    piss on it, just a great excuse to big bore it!
  13. Patches

    Patches XS650 Junkie

    OK, I feel terrible about this one. I sold Rexxis the bike. At the time I sold it the bike did kick and had good compression, but that was all I knew about it. I'm not calling Rex out by any means. He was a super nice guy to deal with. He was looking to move quickly on getting a bike and start his project. My intentions were to take all of these bikes and get as many of them running and back on the road as possible and then sell them as running rollers. But due to his time frame the best I could do for him was make sure the motor was free and let him pick if he wanted BS38 or BS34 carbs, give him the corresponding boots, and let him pick mag or spoke wheels and get them swapped out for him.

    Rexxis - are you sure you didn't kick the bike at all? I probably kicked it a dozen or so times at the shop.

    I know it's not much, but if you do decide to go to 1 OS rings and pistons I randomly have one set of rings sitting at the shop (accidentally put quantity of 3 in shopping cart on MikesXS) and I would gladly send them to you for free.

    I don't want anyone to ever feel like they have been ripped off by me. I would never do that to anyone. I try to be as accommodating as possible. I do not do this for a living, but rather as a hobby for something to do while not working.
  14. Rexxis

    Rexxis Almost there...

    Nice timing Patches, I was just PMing you. I don't have any reason to call Patches out either bc no, I never kicked the bike over till this weekend. He was a real nice guy as well and didn't strike me in the least as the type to try to rip anybody off.

    The motor has sat in my garage until abt three weeks ago when I brought it inside my house to start going over it. It's way too hot here right now to work outside, daily temps are around 105*F and have been for the last 2-3 months.

    I would greatly appreciate the rings, it will save me some $ if I cant get away w just a honing. I'm gonna try to clean up the cylinder so I can get a good look at it. If it starts to look like I'll have to have them bored then I'll get in touch with you Patches, I still have your num.

    Dumb question warning*******

    So, how would a guy apply the phosporic acid without removing any flesh and/or losing an eye? I've got the gloves and face shield ready but do you just dip the whole block in there or what?
  15. sgallaty

    sgallaty Antihero

    Phosphoric acid is very mild. How I did it was filled up a bucket with 5:1 solution (a homer bucket etc.) and shoved the heads in it. It'll fizz up.

    The acid really is very mild (They put phosphoric acid in soda to give it a bite).

    Use eye protection rated for liquids (home depot) and a decent pair of long sturdy rubber gloves.

    Within 30-45 minutes the rust will turn into a black powder. Use a brass brush (won't scratch the metal) or better a plastic one to abrade the rust to get the acid deep in it.

    when you want to dispose it, dilute it twice and throw it on the lawn. It's harmless.
  16. Rexxis

    Rexxis Almost there...

    The topic of sleeve removal kept popping up in here and I just found this:

    Heres the thread: http://www.xs650.com/forum/showthread.php?t=6757

    Good stuff there:thumbsup:

    I spent most of the afternoon today trying to find phosporic acid, I hit up Lowes, Home Depot, Auto zone and finally Ace which had some naval jelly which is phosphoric acid in a jelly form.

    Tomorrow my plan is to use the jelly and a toothbrush to work it onto the rust. Pics to follow.
  17. Gotta say Im impressed and glad to see somebody like Patches who actually has the principles enough to care what happens with a bike even after he got the money in his hand for it, these type of things are becoming rare these days... Much respect Patches you Rock bro!
  18. Rexxis

    Rexxis Almost there...

    Well, the naval jelly got the light rust off but basically didn't do much, if I ever need phosporic acid again, Im gonna start off looking at places that do custom concrete or something bc I couldn't find it at any of the hardware stores, Lowes, Home Depot...
    Here's a shot of the cylinder after using the jelly and a toothbrush


    So, today after work I drove around for abt an hour, machine shop to machine shop, until finally I was directed to a shop that was knowledgeable and could handle engines of this size. The guy was super cool and recognized the block as a XS block almost right away. :thumbsup: He honed the cylinders for free and this is what we had afterward.


    As you can see just a hone isn't gonna cut the mustard so 1 over bore will be happening soon as new pistons and rings get here.
  19. sgallaty

    sgallaty Antihero

    Yeah, not what I suggested. Phosphoric acid in solution, immerse for 45 minutes. No abrasion. I never suggested using naval jelly.

    Not to sound too harsh but you can either use the right tool, or risk doing harm.
  20. cros36

    cros36 thread killer

    he did work for free? put that dudes number in your phone for sure. good luck!

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