No power on my 4500 bd

Discussion in 'Mud Motors' started by threeforthree, Oct 8, 2018.

  1. threeforthree

    threeforthree Senior Refuge Member

    Messages:
    454
    Joined:
    Mar 1, 2005
    Location:
    canada
    Dis a carb job, and valves, engine runs smooth.When in water I can get up to 4300 RPM but I got no power. max on gps is 10mph, two years ago it was 25 mph.. have new prop on also..belt tension is 14 lb ...I can not get that small rooster tail like I got before, seems maybe Im not getting, prop speed the same as engine speed would it be the clutch??
     
  2. ksgoosekillr

    ksgoosekillr Senior Refuge Member

    Messages:
    757
    Joined:
    Aug 7, 2007
    Location:
    Salina, ks
    I would start with some simple stuff first. spark/fuel/air
    1. are both cylinders firing? unplug one wire while running and find out.
    1a. assuming it idles fine, my guess its your high speed jet that is clogged when you did your carb job.
    1b. exhaust/intake clogged at all?
    2. do a simple compression check of each cylinder, with throttle full open (this will tell you if you have a problem)
    3. do a leak down test (this will tell you where the problem is if you have one)
    4. reset valve lash to recommended settings, did you replace valves with SS? or just lap them? what was your intake/exhaust lash set too? TDC method or rollover?
    5. how worn was your old prop? since you say 4500bd, assuming new prop is 12" OD?
    6. did you reuse your head gaskets when you did your valves? take some carb cleaner and spray around your gaskets when running if your engine speed changes you have a leak.
    7. have you smelled a burning smell when you test drove it last? I had a similar issue with the clutch, search my user name on that place that "talks about mud motors" and "clutch"

    if i was betting man im gonna guess high speed jet clog or valve lash issue.
     
  3. Olefart

    Olefart Senior Refuge Member

    Messages:
    359
    Joined:
    Jan 1, 2014
    Location:
    Muscatine, Iowa
    Might check lower drive sprocket, might have key way issue., also key in clutch.
     
  4. threeforthree

    threeforthree Senior Refuge Member

    Messages:
    454
    Joined:
    Mar 1, 2005
    Location:
    canada
    Called Mudbudddy, thinks my boat may be waterlogged?
     
  5. warrenwaterfowler

    warrenwaterfowler Senior Refuge Member

    Messages:
    675
    Joined:
    Jun 25, 2013
    Location:
    Michigan
    Huh? Your aluminum boat is waterlogged? That seems like a stretch
     
  6. ksgoosekillr

    ksgoosekillr Senior Refuge Member

    Messages:
    757
    Joined:
    Aug 7, 2007
    Location:
    Salina, ks
    did you go check out the thread im talking about above? i had the exact same issue with my motor. Mudbuddy is flat out wrong and has horrible customer service. The worst i have ever dealt with.
     
  7. threeforthree

    threeforthree Senior Refuge Member

    Messages:
    454
    Joined:
    Mar 1, 2005
    Location:
    canada
    thanks for the PM, again I can get to 4300 rpm no problem with prop running in water, boat has dripped out about a2.5 gal in two days.
     
  8. HaydenHunter

    HaydenHunter Elite Refuge Member

    Messages:
    10,390
    Joined:
    Dec 4, 2000
    Location:
    Hayden Lake, ID USA
    Some foam will waterlog. It can add hundreds of pounds of weight to a boat. Especially stuff in the floor. Old Godevil boats, for example, were prone to this (they are not now). Google "waterlogged flotation foam" and you will get videos plus some ways to check for this.

    I think ksgoosekiller gave good advice in post #2, especially the compression and leakdown test suggestions. But if your boat now weighs 500 lbs more because of waterlogged foam that can contribute to a performance decrease.
     
  9. ksgoosekillr

    ksgoosekillr Senior Refuge Member

    Messages:
    757
    Joined:
    Aug 7, 2007
    Location:
    Salina, ks
    what do you mean dripped 2.5 gals? like as in water from the rig or as in fuel?
     
  10. ksgoosekillr

    ksgoosekillr Senior Refuge Member

    Messages:
    757
    Joined:
    Aug 7, 2007
    Location:
    Salina, ks
    have you opened up your upper housing on the outdrive? check for oil/and or black dust along the bell housing/clutch.
     

Share This Page