OS Piston Pin

[Verne Koester]

Mike,
You hit the nail on the head and that's exactly what was happening. My varnish buildup on the wrist pin was more than just a little, though. I also had my carb gum up and stick on me causing a very hot landing about a month ago. I've experienced this before and it's always when I switch from one brand of fuel to another. I broke the motor in last fall on one brand and then changed brands at the start of the season. The carb problem surfaced three flights later. Both of these fuels are top brands and I don't use castor. I don't view this as a slight on either fuel. It seems that things happen when going from one synthetic oil to the next. It was a real bugger getting that rod to slide on the wrist pin. Taking the wrist pin out of the piston took more force than you'd expect too. Got the varnish off and all is well. Glad I did this. The rear bearing is totally shot with rust and the retainer looks like it was on borrowed time. I'll be putting in a stainless bearing I bought from Jerry Budd tomorrow. Much easier at home than at the Nats. Thanks to all who responded. Lesson learned from this end.

Verne
  ----- Original Message ----- 
  From: michael Medlin 
  To: discussion at nsrca.org 
  Sent: Wednesday, July 02, 2003 12:54 AM
  Subject: Re: OS Piston Pin


  Verne, sometimes the rod will get caught in varnish that forms on the wrist pin. Turn it to BDC, take an L-shaped allen wrench and position it behind the rod as close to the piston as possible, and give it a pull. Try to pull it evenly at top and bottom. You may have to spray a little penetrating oil on the wrist pin to get it to break loose. It should come out and go back in at BDC.

  Michael
    ----- Original Message ----- 
    From: Verne Koester 
    To: discussion at nsrca.org 
    Sent: Wednesday, July 02, 2003 12:04 AM
    Subject: Re: OS Piston Pin


    Steve,
    I've got the sleeve out but I can't get the rod off the crank pin to save my life. The piston is at TDC. Troy's all wet about doing it at BDC. The groove machined in the case won't allow the rod to slide off the crank pin. I assume that when you were talking about tapping the backplate on a wood block, you were describing how to get the rear bearing out. My problem is getting the piston and rod off the crank. Just won't go. I get it about 3/4 of the way off and then it's stuck.

    Verne


      ----- Original Message ----- 
      From: Patternrules at aol.com 
      To: discussion at nsrca.org 
      Sent: Tuesday, July 01, 2003 11:22 PM
      Subject: Re: OS Piston Pin


      Verne pull the sleeve out then the piston and rod will come out together then you can push the pin out from the other side, just done mine this morning, the Webra has the threaded pin.

      Steve Maxwell 
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