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  1. #1

    GP1200 rebuild question -Am I crazy or just being too cheap??

    I picked up a 97 gp1200 a while back with a grenaded engine. Been buying all the cases, new crank, etc on a very slow pace as I found a deal on stuff over the last couple of years. Last summer it just seemed I couldn't find time to work on putting the damn thing together so this summer I talked with my local independent about just building the motor for me to get on with this..

    Anyhow what he threw out there labor wise sounded good compared to what I was thinking so decided to let them do it instead of waiting on myself to find time from work.. I've done a lot of reading here & picked up my last few parts recently from a forum member. I had a broken sleeve so bought his good cylinder assembly with 2 good sleeves.

    The sleeves have some rust on them from sitting (inside un-oiled) for a couple of years -both on the inside bore & outside surfaces. When I dropped everything off the shop's mechanic made some snide comments & looked at me like I was the antichrist..

    I'm just wondering if I was way off base in my assumptions as follows:

    1) All the sleeves are standard bore currently. I assumed from the beginning that a bore would be required probably to 1 size over so it's not that I thought this would be a simple hone & go..

    2) I also assumed that if you're sending out to a machine shop (which they are) then a machine shop that deals in this stuff probably is used to bead, silica or whatever blasting & wouldn't be a huge deal to have those surface-rusted parts cleaned up. I know they don't do that stuff for free but still seemed better (read more financially realistic) than buying 3 new sleeves on account of a little rust.

    Anyhow.. I don't feel like I'm asking for miracles from the place and I guess I'm just looking for a reality check here. For the record I was doing:

    Used good cases (all) -amazing how a failure in these really hoses ya..
    Used good cylinder
    Used (rusty) std bore sleeves cleaned up & bored at least 1 over
    New hotrod crank
    New pro-x pistons, 1 over ??
    Used good head -mine had too much marring
    Rebuild carbs w/ Mikuni parts
    Premix conversion & choke installation
    Oem gaskets

    I've just got a ton into the motor already at this point so was looking to save a bit over buying all new sleeves. Crazy??


  2. #2
    Yamaha artisan Cutlass's Avatar
    Join Date
    Oct 2010
    Madison, WI, USA
    A little surface rust isn't gonna hurt the machine shops ability to clean them up with a bore and hone.
    ProX pistons come in .25mm, .5mm, .75mm, 1.00mm, 1.5mm, and 2.00mm oversizes.

  3. #3
    wet willie's Avatar
    Join Date
    Jul 2012
    Orange TX
    The last cylender i bought i had to have to bored to std it came smaller than std dont worry about the rust it will come off as they bore it and make sure that all of your cylenders are bored the same and i would go with wiseco pistons 85mm thats 1 over. i have a 99 GP 1200 and had to do the same to all my cylenders one of the oil lines came off and fried the cylender so now premix is the way to go.

  4. #4
    Yamaha artisan Cutlass's Avatar
    Join Date
    Oct 2010
    Madison, WI, USA
    wiseco is not high on the list for recreational PWCs. Those forged pistons need a little more clearance in a pwc and more warm up time then typical oem, Pro-x, or other cast pistons.
    Go Pro-x, oem, or maybe wsm.
    I'm not trying to be prick about wiseco, just stating the tried and true opinion of this forum.

  5. #5
    Agreed pro-x wsm for rec

    I bought all my ski's as basket cases ,, both of my 1200's were completely blown one had even run the rod through the cylinders LOL

    I change my own sleeves at home before I bring them to get machined , I had about a grand into my motors after buying parts/cranks /heads/pistons/machining/gaskets/carb kits etx

    on yours I would find Oside Bill's updated jetting for the 1200 ..

    also I don't know how much time you saved having a shop do this ? the only skilled part is in the bore for matching to the pistons you buy

    the rest is less than an hour to put together

  6. #6
    Resident Coffee Addict Oshawapilot's Avatar
    Join Date
    Feb 2012
    Courtice, Ontario
    Just solely for the record, you may read some pooh-poohing on the WSM stuff around here (I did) but I put in a set of 3 plain-jane WSM's when I did my rebuild and have had zero issues. It's a recreational machine (not a racer) but I've been known to beat on it a little. The price was unbeatable - all 3 pistons AND rings for less than one OEM piston.

    Anyhow, as for the rust, as long as it's not pitted deeply then there's no reason any machine shop worth their salt shouldn't be able to easily hone it out, as others have mentioned. If they're still acting all weird about it, maybe theres a reason you got a cheap quote from that specific shop and you should move on.

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