Page 3 of 6 FirstFirst 12345 ... LastLast
Results 21 to 30 of 57
  1. #21
    bainer1290's Avatar
    Join Date
    Sep 2006
    Location
    Alberta, Canada
    Posts
    612
    +1
    5
    Thanks for that post. I am hoping that milling 20 thou off will bump the compression enough for 91 octane and to be in that 140-150 psi range. I would like to use a regular head gasket with all the layers as I have read a few cases where a single layer has caused problems with head sealing mostly because of the slight variance in cylinder height as the 3 PV cylinders could have a variance in height since they are 3 separate cylinders. The full head gasket is thought to better deal with this variance.

    So given this scenario is 20 thou the correct amount to mill if I want to use a “full” head gasket? And do I need to worry about changing squish?


  2. #22

    Join Date
    Jul 2019
    Location
    Buffalo, NY
    Posts
    260
    +1
    16
    I have spoken to Chris Newmiller at Newmiller Machine about head work. He said he could cut 2mm off the head and re cut the domes to run on 91 ethanol free, but no 2 up riding.

  3. #23
    bainer1290's Avatar
    Join Date
    Sep 2006
    Location
    Alberta, Canada
    Posts
    612
    +1
    5
    That’s interesting 2mm is close to 80 thou, but with the chambers being re cut then that would offset it a little. I still want to be able to ride with a second person so that option is a bit more aggressive than I want to go.

  4. #24

    Join Date
    Jul 2019
    Location
    Buffalo, NY
    Posts
    260
    +1
    16
    If you call Chris he will figure out your needs and will modify the head accordingly.

  5. #25
    bainer1290's Avatar
    Join Date
    Sep 2006
    Location
    Alberta, Canada
    Posts
    612
    +1
    5
    Sounds good will keep that in mind, was hoping to find some specs so that I could take it to a local engine shop to have them mill the head. Being that I just want to raise the compression if 20 thou off is enough without changing the the chambers that would be ideal as its fairly simple.
    Last edited by bainer1290; 08-14-2020 at 08:00 PM.

  6. #26
    jeffg426690's Avatar
    Join Date
    Jul 2015
    Location
    Sarasota, FL
    Posts
    615
    +1
    64
    Reread your original post, w 230 hrs on the crank I'm not sure I'd do anything w the compression as increased compression is more wear and stress on the crank. That being said, 20 thou off put me at about 138 w oem gaskets complete. I run 93 octane in it, have had no issues and has plenty of grunt in midrange w the Oside recipe in the carbs.

  7. #27
    bainer1290's Avatar
    Join Date
    Sep 2006
    Location
    Alberta, Canada
    Posts
    612
    +1
    5
    I appreciate that Jeff and yes makes sense with a 20 year old crank that would have some wear with the 230 hours. On your head was it just 20 thou off the gasket surface so the chambers and squish were left as is? Are you running stock pistons? Thanks

  8. #28
    bainer1290's Avatar
    Join Date
    Sep 2006
    Location
    Alberta, Canada
    Posts
    612
    +1
    5
    I have been able to locate a powersports shop in Edmonton Alberta that I will be taking the crankshaft to for an inspection, repair if needed and a true/welding. I talked to him on the phone the other day and he sounded like he knows his stuff. https://motsmachining.com/ He also does cylinder head work so I think I will get him to take 20 thou off my head to give a bit of a compression bump. Anyone heard of this shop before?

  9. +1 by:


  10. #29
    bainer1290's Avatar
    Join Date
    Sep 2006
    Location
    Alberta, Canada
    Posts
    612
    +1
    5
    Starting to look at flame arrestors, seems tough to find used sbn 44 adapters and 3 F/A's on ebay or in the clasifieds here. I have read that a few have used the stock air box, but removed the intake pipe and added a cone K&N style filter. Any pics of this setup? Do you remove the metal screen in the airbox or leave it in place? Would you still jet 125 main and 110 pilots with this, basically Bill's setup?

  11. #30

    Join Date
    Jul 2019
    Location
    Buffalo, NY
    Posts
    260
    +1
    16
    There is a recipe in one of OsideBill's posts about gutting the air box (drilling holes) and removing the pipe. I have photos of the airbox on my phone. My son and I were able to obtain some Prok's from the Jetski Store. He sells a gp1200r kit on Ebay for like $170 American.

Page 3 of 6 FirstFirst 12345 ... LastLast

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. 2000 gp1200r carb rebuild questions
    By WillieD in forum Yamaha How To & FAQs
    Replies: 1
    Last Post: 08-25-2020, 07:55 AM
  2. 2000 GP1200r Rebuild Imminent - Need Advice
    By LipschitzWrath in forum Yamaha PWC Performance (2-stroke)
    Replies: 27
    Last Post: 08-12-2018, 11:32 PM
  3. 2000 GP1200r Rebuild Imminent - Need Advice
    By LipschitzWrath in forum Yamaha PWC Performance (2-stroke)
    Replies: 0
    Last Post: 07-18-2018, 07:53 PM
  4. WTB - Parts Carb setup for 2000 Gp1200r, Preferably working/not in need of a rebuild
    By ndj22 in forum Yamaha Classifieds
    Replies: 1
    Last Post: 06-20-2016, 08:53 PM
  5. 2000 GP1200R Rebuild/Mod Questions!
    By Mustang Matt21 in forum Yamaha PWC Performance (2-stroke)
    Replies: 4
    Last Post: 07-17-2014, 03:27 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
  •