Page 3 of 4 FirstFirst 1234 LastLast
Results 21 to 30 of 34
  1. #21

    Join Date
    Apr 2021
    Location
    Sydney
    Posts
    66
    +1
    1
    Quote Originally Posted by steve45 View Post
    Pull the engine.

    To pressure test the crankcase, you have to build a fixture with a low pressure gauge some hoses and fittings. I use a needle valve on mine and I run my compressor, then turn it off so the only pressurized air I have is in the line itself. You don't want much because you can ruin the brand new seals if you overpressure it. Apply pressure very slowly with the needle valve, then close it and watch it for about 10 minutes to make sure it doesn't bleed off. You'll have to figure out ways to block off the intake & exhaust, pulse line, etc. There are lots of videos online to walk you through it.
    Thanks for the feedback, it looks like i'm pulling the engine.
    I was really trying to avoid pulling the bottom end but i guess there's no point rebuilding the top end if the bottom has issues.
    Is there a way to check the oil and fuel lines to make sure they're both going to all cylinders?


  2. #22

    Join Date
    Apr 2021
    Location
    Sydney
    Posts
    66
    +1
    1
    Also the ski has an EJK fuel controller which I've never touched since I bought the ski as it was running fine or so I thought, and I don't even know if it's set correctly.
    Last edited by Shadyraro; 10-27-2021 at 10:53 PM.

  3. #23

    Join Date
    Apr 2021
    Location
    Sydney
    Posts
    66
    +1
    1

    GP1300 stuffed piston

    So I pulled the engine and stripped it down, and Iíve found that the centre connecting rod big end bearing has seized, so basically the crankshaft is now junk.
    Iím not sure what Iím going to do now, Itís getting to the point now where the cost for me to rebuild it will be in excess of 2k
    Last edited by Shadyraro; 10-29-2021 at 05:22 PM.

  4. #24

    Join Date
    Apr 2021
    Location
    Sydney
    Posts
    66
    +1
    1
    So today I got the crankshaft onto the bench to give it a proper inspection. I sprayed some wd40 into the bearings to try loosen them up and they did. All bearings move freely but Iím not sure if theyíre all supposed to be quiet as a couple are a little noisier than others.
    Is there a way to remove the flywheel magneto and drive coupling without the specialised tools?

  5. #25
    butterbean_29512's Avatar
    Join Date
    Sep 2013
    Location
    Bennettsville, SC
    Posts
    1,625
    +1
    172
    Remiving the flywheel is pretty straight forward, even with the crank out. The coupler.....not quite as easy. The coupler should always be removed before the engine is torn apart. It is a standard right hand thread, so righty tighty lefty loosy on it. Probably best to just chuck the crank in a vise to get the coupler off now. Good luck! Also, that stopping and restarting, and acting like the battery was dead was a sure sign of a seized engine. When seized all you hear is a click, then when the engine cools off it unseizes, and will sometimes run for a minute or two more. My 1200r seized this summer due to the oil pump suction hose rotting in two. Never use anything but a good quality rubber hose, or the oem hose for that line!

  6. +1 by:


  7. #26

    Join Date
    Apr 2021
    Location
    Sydney
    Posts
    66
    +1
    1

    GP1300 stuffed piston

    Quote Originally Posted by butterbean_29512 View Post
    Remiving the flywheel is pretty straight forward, even with the crank out. The coupler.....not quite as easy. The coupler should always be removed before the engine is torn apart. It is a standard right hand thread, so righty tighty lefty loosy on it. Probably best to just chuck the crank in a vise to get the coupler off now. Good luck! Also, that stopping and restarting, and acting like the battery was dead was a sure sign of a seized engine. When seized all you hear is a click, then when the engine cools off it unseizes, and will sometimes run for a minute or two more. My 1200r seized this summer due to the oil pump suction hose rotting in two. Never use anything but a good quality rubber hose, or the oem hose for that line!
    Thanks for your input, Iíve decided not to remove them now as I really donít see any point. The seals all look brand new, and all the bearings are moving freely. What I did notice tho when I removed the reeds which are VF3, the reed plate was slightly damaged on top of the second cylinder, like it had been hit with something. This had a lip which caused the plate to not sit completely flush. This has got me thinking that maybe there was an air leak in that cylinder which just happened to be the bad one.

  8. #27

    Join Date
    Apr 2021
    Location
    Sydney
    Posts
    66
    +1
    1
    Click image for larger version. 

Name:	IMG_6842.jpg 
Views:	28 
Size:	105.0 KB 
ID:	480136

  9. #28
    steve45's Avatar
    Join Date
    Feb 2008
    Location
    Texas
    Posts
    8,737
    +1
    909
    A damaged bearing that has been 'freed up' with WD-40 is still a damaged bearing.

    I'd bet money that it won't last more than 5 hours, then it's going to come out the side of the block and get REALLY expensive. You CAN get the crank rebuilt for a lot less than buying a new one.

  10. #29

    Join Date
    Apr 2021
    Location
    Sydney
    Posts
    66
    +1
    1
    Quote Originally Posted by steve45 View Post
    A damaged bearing that has been 'freed up' with WD-40 is still a damaged bearing.

    I'd bet money that it won't last more than 5 hours, then it's going to come out the side of the block and get REALLY expensive. You CAN get the crank rebuilt for a lot less than buying a new one.
    Yeah I realise that but what defines a damaged bearing? The roller pins do not look damaged at all, the rest of the bearings look good also.
    I even temp fitted it inside the case and it ran smooth as.
    Iím just trying to convince myself that the crank doesnít need a rebuild when I know it does.

  11. #30
    steve45's Avatar
    Join Date
    Feb 2008
    Location
    Texas
    Posts
    8,737
    +1
    909
    Quote Originally Posted by Shadyraro View Post
    I’m just trying to convince myself that the crank doesn’t need a rebuild when I know it does.
    Can't help you with that.

Page 3 of 4 FirstFirst 1234 LastLast

Thread Information

Users Browsing this Thread

There are currently 4 users browsing this thread. (0 members and 4 guests)

Similar Threads

  1. FS - Parts New Pro-x piston kit gp1300
    By crashhard in forum Yamaha Classifieds
    Replies: 1
    Last Post: 03-24-2016, 07:34 PM
  2. GP1300 Another middle piston seized
    By VdeKock in forum Yamaha PWC Performance (2-stroke)
    Replies: 17
    Last Post: 08-20-2014, 05:58 PM
  3. 03 GP1300 looking for a Cylinder jug and new piston. Anyone have one?
    By pnkrckchiro in forum Yamaha PWC Performance (2-stroke)
    Replies: 0
    Last Post: 07-08-2011, 01:47 PM
  4. gp1300 piston size
    By brisyl in forum Yamaha PWC Performance (2-stroke)
    Replies: 3
    Last Post: 08-07-2009, 03:43 AM
  5. Best Piston GP1300
    By ctct2118 in forum Yamaha PWC Performance (2-stroke)
    Replies: 1
    Last Post: 07-21-2009, 11:20 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •