Results 1 to 9 of 9
  1. #1

    how to test oil pump on MSX 150 Weber?

    Starting work on my second MSX150.

    Engine apart due to chewed up con rod big end bearing. Crankshaft will need rebuilding also. It was obvious from the discoloration of the crankshaft that overheating of this rod had occurred, and had warped a little, although within tolerances to be corrected.

    I rebuilt a clapped out Mercury inboard once, only to have it fail, due to a worn out oil pump, so I had to rip it apart again for new shells and oil pump. I would like to avoid this with the MSX, (who wouldn't if they have ever removed the engine from one)

    Nikasil plating was fine, but I welcome any info on what might have caused this, but as a starting point, I would like to check the oil pump pressure with the pump on the bench, anyone have any idea how to do this?

    Thanks, Les
    Last edited by K447; 03-20-2017 at 10:12 AM.


  2. #2
    ripcuda's Avatar
    Join Date
    May 2010
    Location
    Newman Lake, WA
    Posts
    2,478
    +1
    186
    High pressure oil pump... or sump pump (low pressure)?

    Always replace the high pressure oil pump (rear-side of engine... runs off end of counter-balance shaft). It's only like $40 bucks from Weber Power.

    I've never seen a sump pump go bad. As long as it spins smoothly... and you clean it out... including the sump screen... it'll be fine.

    You can test oil pressure when the engine is assembled and running. Easiest to get to spot is the banjo bolt on the rear-side of the head that sends oil to the turbo (and top of the oil tank when using the stock round metal oil tanks). You'll have to get creative with connecting of fittings. The oil pressure switch locale on the lower left (exhaust) side of the block is near impossible to get to when the engine is in the hull. There is also a small fitting capped off under the oil filter base (exhaust side of block). Folks have connected a flex-braided hose there for an oil pressure source.

    Cheers!

  3. +1 by:


  4. #3
    Moderator HiPeRcO's Avatar
    Join Date
    Jul 2007
    Location
    Upstate NY
    Posts
    2,631
    +1
    188
    Quote Originally Posted by dunromin View Post
    Starting work on my second MSX150.

    Engine apart due to chewed up con rod big end bearing. Crankshaft will need rebuilding also. It was obvious from the discoloration of the crankshaft that overheating of this rod had occurred, and had warped a little, although within tolerances to be corrected.
    Spun connecting rod bearings are very common on higher hour machines (how many hours on yours?). Mr. Hill believes that the connecting rod bearings were set to too little clearance from the factory, and recommends looser bearings for the re-build ("red", if I recall correctly). Based on other instances of this, I think advice would be to NOT re-use the crankshaft....

    Regarding the oil pump, I would do whatever Mr. ripcuda advises

  5. #4
    Quote Originally Posted by HiPeRcO View Post
    Spun connecting rod bearings are very common on higher hour machines (how many hours on yours?). Mr. Hill believes that the connecting rod bearings were set to too little clearance from the factory, and recommends looser bearings for the re-build ("red", if I recall correctly). Based on other instances of this, I think advice would be to NOT re-use the crankshaft....

    Regarding the oil pump, I would do whatever Mr. ripcuda advises
    Two oil pumps? Who knew? Checking Weberpower's site confirms this of course, but now I have to ask, what is the function of each pump? I can't say how many hours on this ski, I have only the engine in my shop, the rest of it is elsewhere.
    I have already removed the ball bearings that seal access to the main and con rod bearing oil ways, to facilitate a good cleaning of any metal particles, (there was a whopper lodged in the oil hole of one of the main bearing journals) and the specialist I use doesn't see a problem with truing it up, and chroming the journals, in fact, it's in his shop right now, so I'm committed to going that route, but my experience with these engines is non existent, so if I'm overlooking something, please tell me. The theory about clearances sounds very plausible, and since my shells had no colors evident, I planned on supplying the largest dimension of new ones, clamped up in the rods to the correct torques, so the journals could be ground to suit.
    Could anyone offer any advice on acceptable clearances for the con rod big end?

    Les

  6. #5
    Moderator HiPeRcO's Avatar
    Join Date
    Jul 2007
    Location
    Upstate NY
    Posts
    2,631
    +1
    188
    Quote Originally Posted by dunromin View Post
    Two oil pumps? Who knew? Checking Weberpower's site confirms this of course, but now I have to ask, what is the function of each pump? I can't say how many hours on this ski, I have only the engine in my shop, the rest of it is elsewhere.
    I have already removed the ball bearings that seal access to the main and con rod bearing oil ways, to facilitate a good cleaning of any metal particles, (there was a whopper lodged in the oil hole of one of the main bearing journals) and the specialist I use doesn't see a problem with truing it up, and chroming the journals, in fact, it's in his shop right now, so I'm committed to going that route, but my experience with these engines is non existent, so if I'm overlooking something, please tell me. The theory about clearances sounds very plausible, and since my shells had no colors evident, I planned on supplying the largest dimension of new ones, clamped up in the rods to the correct torques, so the journals could be ground to suit.
    Could anyone offer any advice on acceptable clearances for the con rod big end?

    Les
    The conn rod clearance is suggested to be 0.002 (on the very high side of the spec which is 0.0009-0.0021), which is typically achieved with red or yellow bearings.

    If you don't have a manual, you need to get one The sled ("FST") manual is the one to get, its much better than the watercraft version.

  7. #6
    ripcuda's Avatar
    Join Date
    May 2010
    Location
    Newman Lake, WA
    Posts
    2,478
    +1
    186
    Quote Originally Posted by dunromin View Post
    Two oil pumps? Who knew? Checking Weberpower's site confirms this of course, but now I have to ask, what is the function of each pump?
    The Weber is a dry sump 4-stroke. As such... there is a sump pump that moves oil out of the sump, through the oil cooler and back into the oil reservoir (big oil tank). The other pump... is the normal oil pump for the engine... just called the "high pressure" one to differentiate it from the sump pump.

    Cheers!

  8. #7
    Thanks to both of you, as always, a big help.

    Les

  9. #8
    Moderator HiPeRcO's Avatar
    Join Date
    Jul 2007
    Location
    Upstate NY
    Posts
    2,631
    +1
    188
    Quote Originally Posted by dunromin View Post
    I have already removed the ball bearings that seal access to the main and con rod bearing oil ways, to facilitate a good cleaning of any metal particles, (there was a whopper lodged in the oil hole of one of the main bearing journals) and the specialist I use doesn't see a problem with truing it up, and chroming the journals, in fact, it's in his shop right now, so I'm committed to going that route, but my experience with these engines is non existent, so if I'm overlooking something, please tell me.

    Les
    I would strongly advise that your specialist inspect the crank for cracks via magnaflux or similar, if he hasn't already. It seems that it's common for them to crack when a bearing spins (this according to Randy at Weberpower.com).

  10. #9
    Mike Greenwood's Avatar
    Join Date
    Jun 2015
    Location
    Tulsa, Oklahoma
    Posts
    701
    +1
    57
    It has been awhile since my last visit here. Sorry guys I had to move. I plan on breaking into my secret stash that is locked in my connex here shortly. If you have a difficult time locating a used crank let us know.

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. Oil Pump working or not, how to test?
    By heebeha in forum Polaris Open Discussion
    Replies: 16
    Last Post: 06-19-2012, 08:08 AM
  2. how to test oil sending unit on 99 STX
    By jdy2kgt in forum Kawasaki PWC Performance (2-stroke)
    Replies: 2
    Last Post: 06-20-2009, 04:50 PM
  3. how to adjust oil pump cable?
    By tgersx in forum Polaris Open Discussion
    Replies: 1
    Last Post: 06-09-2009, 09:04 AM
  4. how to check oil pump
    By txgp1300r in forum Yamaha PWC Performance (2-stroke)
    Replies: 2
    Last Post: 09-10-2007, 08:16 AM
  5. how to test oil injection
    By dont kno crap in forum Polaris How To & FAQs
    Replies: 24
    Last Post: 05-14-2007, 10:29 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
  •