Results 1 to 4 of 4
  1. #1

    dying crank speed

    My 650 sucked in one of the airbox mounting screws which jammed up the rotary valve (I know, I know)but didn't get into the cylinder.Removed the screw.
    I straightened up the kink in the valve cutout and cranked the engine without the rotary cover. With the plugs in,starter engages flywheel but doesn't turn over.
    With the plugs out, starter cranks normal speed, becoming progressively slower until it stops.Fingers covering plugholes, no crank as before.
    Sounds like a starter problem.Anyone have any other ideas before I strip the engine.??


  2. #2
    fast96HX's Avatar
    Join Date
    Apr 2007
    Location
    Salt Lake City, Utah
    Posts
    124
    +1
    2
    Hi, I just did the same thing to the 720 in my HX. One of the screws from my westcoast flame arrestor fell into the intake and jammed up in the rotary valve while riding. In short, my parts list includes a new crank, new rotary valve, new rotary valve shaft, and a new brass gear. I tore my engine apart because it would no longer turn over without the plugs in. I found out that the crankshaft gear moved towards the pto side of the crank. Also, the rotary valve shaft was bent beyond the tolerances. So, I'm sorry to say it, but I would expect the same story for you as well. However, you won't know until you take your engine apart.

    Rob

  3. #3
    Tool Bag water worx's Avatar
    Join Date
    Aug 2006
    Location
    Sunny Fla
    Posts
    1,925
    +1
    66
    Quote Originally Posted by fast96HX View Post
    Hi, I just did the same thing to the 720 in my HX. One of the screws from my westcoast flame arrestor fell into the intake and jammed up in the rotary valve while riding. In short, my parts list includes a new crank, new rotary valve, new rotary valve shaft, and a new brass gear. I tore my engine apart because it would no longer turn over without the plugs in. I found out that the crankshaft gear moved towards the pto side of the crank. Also, the rotary valve shaft was bent beyond the tolerances. So, I'm sorry to say it, but I would expect the same story for you as well. However, you won't know until you take your engine apart.

    Rob
    Fast is probally right about the gear being stripped.

    Also Fast if you need a new crank I can sell you a brand new Hotrods crank for $360 & I have some used RV shafts with gears.PM me if interested.

  4. #4

    dying crank speed

    Thanks boys
    Not what I wanted to hear , of course, so well just have to stay here in South Africa and drown my sorrows on $3 wines and 75c beers.

Thread Information

Users Browsing this Thread

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

Similar Threads

  1. GP800 runs perfectly then dies at speed and then starter motor hardly turns over
    By Kiwivetten in forum Yamaha PWC Performance (2-stroke)
    Replies: 5
    Last Post: 10-07-2015, 03:53 AM
  2. 780 slt dies at top speed
    By chinman in forum Polaris Open Discussion
    Replies: 12
    Last Post: 05-10-2012, 10:25 PM
  3. 01 XLT1200--dies--no cranking..
    By CRT racing in forum Yamaha Open Discussion
    Replies: 7
    Last Post: 08-21-2009, 06:51 PM
  4. 99 XPL dies out at speed
    By ChipGriffith in forum 2-Stroke Performance
    Replies: 24
    Last Post: 05-27-2009, 05:05 AM
  5. 250 Dies At Speed
    By PROJECT X in forum Kawasaki PWC Performance (4-stroke)
    Replies: 8
    Last Post: 08-21-2007, 01:00 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
  •