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Thread: Basic Jet Tech Questions...

  1. #1
    455Rocket
    Now that I have one dilemma solved I'll move on to a few larger issues:
    Drive train noise-
    So I’ve heard (from very reliable sources) that it is normal for the jet to make a grinding, rattling, unsettling noise that reverberates up the hull when idling... and that it is only slop between the U-joint shaft and jet. If it disappears while underway then all is well... Agreed?
    Grease flyby-
    My old jet would sling grease like a S.O.B after pumping a few shots in the zert... my new one (after a VERY liberal greasing) does not... Shall I keep the grease flowing until it does, or is this the sign of a tight jet?

  2. #2
    kaqster
    Dont worry so much if your performance hasnt gone down. I had a Cal performance 19' with a tight Jet Drive that rattled and sounded weird at idle but kicked ass on plane. If no rocks, etc in drive f_ck it, run her!

  3. #3
    SmokinLowriderSS
    If it makes any grinding noises or vibrates ANY above idle (under a load), tripple check the thrust bearing. If it fails, the pump shaft slides foreward, and pushes on the crankshaft. I've seen suction pieces eaten out by the impeller, I've heard of ruined cranks from being driven fwd thru the thrust bearing in the engine to rub the block. Otherwise, drive it!

  4. #4
    455Rocket
    On the grease problem... anyone?

  5. #5
    Senior Member
    Join Date
    Feb 2009
    Posts
    2,626
    Was the grease coming from the u-joints or from the front bearing area? Either way it sounds like you may have overgreased the old pump and/or u-joints.
    BTW, it's "zerk" fitting.

  6. #6
    Sanger Jet
    Now that I have one dilemma solved I'll move on to a few larger issues:
    Drive train noise-
    So I’ve heard (from very reliable sources) that it is normal for the jet to make a grinding, rattling, unsettling noise that reverberates up the hull when idling... and that it is only slop between the U-joint shaft and jet. If it disappears while underway then all is well... Agreed?
    Grease flyby-
    My old jet would sling grease like a S.O.B after pumping a few shots in the zert... my new one (after a VERY liberal greasing) does not... Shall I keep the grease flowing until it does, or is this the sign of a tight jet?
    This is all very normal to me

  7. #7
    455Rocket
    BTW, it's "zerk" fitting.
    Sorry spell check doesn't catch these things
    I'm talking the "front bearing area." Not the universal

  8. #8
    Senior Member
    Join Date
    Feb 2009
    Posts
    2,626
    Still sounds like you overgreased the previous pump or it had a bad seal. You only need to add one or two shots of grease when you do. If it starts oozing out past the seal, it is full. I think the manual says that 40 shots from a manual grease gun will fill the cavity. Don't know how accurate that is...By any chance was the previous pump a JA?

  9. #9
    455Rocket
    Still sounds like you overgreased the previous pump or it had a bad seal. You only need to add one or two shots of grease when you do. If it starts oozing out past the seal, it is full. I think the manual says that 40 shots from a manual grease gun will fill the cavity. Don't know how accurate that is...By any chance was the previous pump a JA?
    Thanks...
    The last pump was a 12JC

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