Page 1 of 2 1 2 LastLast
Results 1 to 10 of 17
  1. #1

    Need help with low compression

    Ok so Ive seen all the posts about timing and low compression and my guess is I'm off a couple teeth. In the pic you can see that its not even close to lined up #3 is at tdc and my compression is at 120. That's the most Ive been able to get out of it going either way. Just got back from the garage from moving the teeth over and still only 120. What do you guys think what am I missing. Oh its a fresh motor and its being checked cold.
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	IMAG0079.jpg 
Views:	69 
Size:	71.3 KB 
ID:	207519  


  2. #2
    Having Fun jp1300r's Avatar
    Join Date
    Sep 2005
    Location
    Florida
    Posts
    5,334
    +1
    261
    Are you using a crank locking tool?

  3. #3
    Gone in 3.0 seconds... RXPT400's Avatar
    Join Date
    Nov 2007
    Location
    USA
    Posts
    1,527
    are you opening the throttle all the way while cranking the engine?...were the head valves removed?...set the engine timing properly and do a cylinder leakage test and see what you get from there..

  4. #4
    SingTH's Avatar
    Join Date
    Jun 2010
    Location
    Thailand
    Posts
    476
    +1
    9
    Look like the cam timing was retard, Locking crank and check the piston of cylinder#3 on Top (TDC), unlock screw M6 on sprocket cam shaft put the locking camshaft the cam will be correct marking and marking line( 1503) must be horizontal of cylinder head then locking screw cam and re-check the compression again.
    Or the valve bounce the piston as your miss timing and not close properly.

  5. #5
    Yes and no I was using a drill bit which I hear works but its not the correct tool for the job I know. I was holding throttle when checking compression but I will go over the steps again pretty sure I'm dead on though got the lines straight across the head and still horrible compression numbers. Oh the head was rebuilt buy Eric at speedfreaks so I'm sure its set up right.

  6. #6
    West Texas RXP skoepp's Avatar
    Join Date
    Oct 2007
    Location
    west texas
    Posts
    12,019
    +1
    149
    I sent you pm, did you not get it?/?

  7. #7
    Ok bringing this TTT can someone explain if the pic shows the cams advanced or retard and if by going the other way should my compression go up or down? I can tell you that I get 120 PSI as you see it in the latest pic if I loosen the 3 bolts and go counterclockwise with the cam gear I get 90psi. What do you guys think?
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	IMAG0080.jpg 
Views:	68 
Size:	102.7 KB 
ID:	207602  

  8. #8
    formerly Gold06RXP Turbo Nick's Avatar
    Join Date
    May 2007
    Location
    Dayton, OH
    Posts
    2,095
    +1
    97
    Its low no matter what. Do a leak down test

  9. #9
    Does that require the rocker shaft to be removed?

  10. #10
    formerly Gold06RXP Turbo Nick's Avatar
    Join Date
    May 2007
    Location
    Dayton, OH
    Posts
    2,095
    +1
    97
    To make it as accurate as possible I would losen it to make sure all the valves are closed

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. Help with Low Engine Compression
    By brl96 in forum 4-Tec Performance
    Replies: 3
    Last Post: 09-16-2012, 03:02 PM
  2. Need help with C-KIT (low boost)
    By elbchecker in forum 4-Tec Performance
    Replies: 14
    Last Post: 08-29-2008, 11:07 AM
  3. Need help with msx140 compression
    By msx140 in forum MSX/Matrix
    Replies: 18
    Last Post: 05-30-2008, 05:20 PM
  4. Need help with pump issue
    By Flyer in forum 4-Tec Performance
    Replies: 17
    Last Post: 05-23-2006, 05:40 PM
  5. Need help with 04 S.C. rebuild
    By Turbo Todd in forum Sea Doo Open Discussion
    Replies: 4
    Last Post: 04-10-2006, 08:03 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
  •