Results 1 to 9 of 9
  1. #1

    What ratio premix? Is it ok to leave to pump for a block off plate?

    I have a few tuning questions, as well as a few tech questions. I have removed the driveshaft for my oil pump and reinstalled just the pump to act as a block-off plate.. Its this ok?? What ratio premix oil should be used with no oil injection, 50:1 ? I am going to run 780 carbs on a 750, I am however running ocean pro vortex flame arrestors, and duel stage boysen reeds, (Thanks B-D) I dont think I will have to re-jet. Any opinions?? I know you would rather run a lil rich than lean, Since I am adding the unrestrictive flame arrestor, and the reeds, I figure this should make up for some of the "Fat" right??


  2. #2
    ph2ocraft's Avatar
    Join Date
    Apr 2006
    Location
    Campbell, Ca.
    Posts
    14,100
    +1
    105
    You should be running it at 40:1. Remember the oil displaces fuel so you are technically running a little leaner in terms of fuel. With the OP's I think I'd give it at least a 1/8 open on the high speed and check it from there.

  3. #3
    ph2ocraft's Avatar
    Join Date
    Apr 2006
    Location
    Campbell, Ca.
    Posts
    14,100
    +1
    105
    i just read what you actaully posted, yeah I'd leave the 780 jetting and then perform some plug chops, you'll probably be too rich.
    I guess you can use the pump as a block off just be sure it has an excellent seal and cap off the oil tube nipples so you have no air leaks.

  4. #4
    cheatin' piston popper addicted's Avatar
    Join Date
    Jul 2006
    Location
    north jersey
    Posts
    6,188
    +1
    176
    if you leave the pump as a blockoff, pull the drive gear from the block. The pump spinning dry will eventually seize up.

  5. #5
    ph2ocraft's Avatar
    Join Date
    Apr 2006
    Location
    Campbell, Ca.
    Posts
    14,100
    +1
    105
    Quote Originally Posted by gvnitup View Post
    I have removed the driveshaft for my oil pump and reinstalled just the pump to act as a block-off plate.. Its this ok??
    I missed it the first time I read it as well, it's almost like it's invisible. LOL

  6. #6
    Al, 1/8 of of a turn on the high speed, what about the low speed??

  7. #7
    Are you swapping jets from the old 750 carbs? if not Al said don't change the HS screws as you'll already be richer do to 780 jetting!

  8. #8
    I am not changing the jetting, But the carbs I bought are way out of adjustment. They were 3 turns on the high, and 1 1/2 on the low. I need a start setting to adjust the screws.. For the plug chops..

  9. #9
    Moderator beerdart's Avatar
    Join Date
    Aug 2006
    Location
    CT
    Posts
    25,929
    +1
    1,407
    Here is a chart try to split the difference. I would start with the 750 adjustments and go from there. The 780 has larger jets Right what size are the 750 and the 780?
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	Manual Appendix.jpg 
Views:	227 
Size:	466.8 KB 
ID:	25155   Click image for larger version. 

Name:	Manual Appendix_0001.jpg 
Views:	132 
Size:	452.0 KB 
ID:	25156  

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. Is it OK to leave your PWC in the water for a week?
    By holdem_up in forum Polaris Open Discussion
    Replies: 3
    Last Post: 07-22-2008, 08:39 AM
  2. so , is it ok to block off the bov ? ? ?
    By GDM in forum Kawasaki PWC Performance (4-stroke)
    Replies: 10
    Last Post: 06-14-2007, 09:25 PM
  3. So is it ok to just block off the bov valve
    By TOQUICK250X in forum Kawasaki PWC Performance (4-stroke)
    Replies: 4
    Last Post: 05-25-2007, 07:21 PM
  4. Is it ok to......
    By Alaska05RXT in forum Sea Doo Open Discussion
    Replies: 9
    Last Post: 04-25-2007, 09:14 PM
  5. Replies: 9
    Last Post: 04-02-2007, 11:14 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
  •