Page 1 of 2 1 2 LastLast
Results 1 to 10 of 12
  1. #1
    Chine Walker
    Join Date
    Nov 2006
    Posts
    598

    Can the engine bolts be replaced with stainless A4 grade bolts??

    Would A4 (316) stainless hardware have the tensile strength to replace the stock engine hardware??

    jp


  2. #2
    All hail the Chief! fullboogie's Avatar
    Join Date
    Nov 2005
    Location
    Texas
    Posts
    3,156
    +1
    44
    Don't use that on the head bolts. They'll stretch and break. Use stock Yami head bolts. Not sure about other applications - maybe someone else will have some advice...

  3. #3
    r33pwrd's Avatar
    Join Date
    Mar 2006
    Location
    Sammamish Washington
    Posts
    4,216
    +1
    360
    Sainless = Not strong I would always use the OEM bolts!

  4. #4
    Moderator beerdart's Avatar
    Join Date
    Aug 2006
    Location
    CT
    Posts
    25,930
    +1
    1,407
    .
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	SocketHeadCapGeneralTorquemetri.jpg 
Views:	58 
Size:	690.3 KB 
ID:	55214  
    Attached Files Attached Files

  5. #5
    ....back from the dead.... J-ME's Avatar
    Join Date
    Aug 2005
    Location
    Delaware
    Posts
    1,577
    +1
    2
    Yes they can. A4 isn't really that necessary or that brittle.

    I have run A2 in salt water w/o corrosion issues. They are alot better that most of Yamahas hard plated fasteners.

    I have also used A4 head bolts without an issue.

  6. #6
    All hail the Chief! fullboogie's Avatar
    Join Date
    Nov 2005
    Location
    Texas
    Posts
    3,156
    +1
    44
    Hmmm. I've broken numerous SS head bolts. Yami's are the only ones that have held up.

  7. #7
    Chine Walker
    Join Date
    Nov 2006
    Posts
    598
    Thanks guys.
    Looks that the head bolts should be kept OEM Yamaha. Is it recomended to use new head bolts each time the head is removed?
    Smaller bolts such as those holding the reeds and EFI throttle bodies may benefit from SS, A2 or A4.
    Not sure if SS would be ok for the exhuast pipe??

    jp

    Ps. Beerdart: Are the OEM Yamaha head bolt rated 12.9 class? M10 12.9 bolts have a recomended torque of 77Nm, a bit higher than the manual states.
    Last edited by jpa1300; 01-29-2008 at 11:27 PM.

  8. #8
    Moderator OsideBill's Avatar
    Join Date
    Mar 2006
    Location
    United States
    Posts
    11,875
    +1
    30
    Quote Originally Posted by jpa1300 View Post
    Thanks guys.
    Looks that the head bolts should be kept OEM Yamaha. Is it recomended to use new head bolts each time the head is removed?
    Smaller bolts such as those holding the reeds and EFI throttle bodies may benefit from SS, A2 or A4.
    Not sure if SS would be ok for the exhuast pipe??

    jp

    Ps. Beerdart: Are the OEM Yamaha head bolt rated 12.9 class? M10 12.9 bolts have a recomended torque of 77Nm, a bit higher than the manual states.
    No need to change OEM headbolts each time you remove them these do not see that much torque. Note: if you are running a stock milled head make sure the bolts do not bottom out use an extra washer if necessary.

  9. #9
    Chine Walker
    Join Date
    Nov 2006
    Posts
    598
    Do you guys use Loctite on the head bolts? I'd rather use anti-seize with proper torque sequence; bad idea??

    jp

  10. #10
    ....back from the dead.... J-ME's Avatar
    Join Date
    Aug 2005
    Location
    Delaware
    Posts
    1,577
    +1
    2
    Quote Originally Posted by fullboogie View Post
    Hmmm. I've broken numerous SS head bolts. Yami's are the only ones that have held up.
    Yamaha mixes it up. Some bolts are coated, while others are stainless. Depends on the year and the application.

    There is ALOT of cheap stainless hardware out there. You get what you pay for.

    I have a SUV here with stainless headbolts, while most GPs have coated.(same engine)

    It is normally easier to strip the threads out of aluminium then to break a stainless bolt.

    Use blue loctite on the head bolts. Synthetic grease on exhaust bolts.

Page 1 of 2 1 2 LastLast

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. Can the engine hour meter be reset?
    By bryanw80 in forum 4-Tec Performance
    Replies: 4
    Last Post: 11-19-2014, 11:05 AM
  2. Replies: 22
    Last Post: 09-09-2014, 03:19 PM
  3. can a stock waterbox be used with a thru hull exhaust?
    By alfmoney in forum Sea Doo Open Discussion
    Replies: 2
    Last Post: 01-30-2009, 08:56 PM
  4. can the ultra pump be removed w/o taking off the rideplate?
    By 1FastRXP in forum Kawasaki PWC Performance (4-stroke)
    Replies: 6
    Last Post: 04-29-2007, 08:45 AM
  5. RXP engine for sell, replacing with 450hp engine
    By Kinchyle in forum Sea Doo Open Discussion
    Replies: 2
    Last Post: 09-21-2005, 06:07 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
  •