Rebuild 550 - Crank Bearings & Seals

[jskal]

Looking for best practice on rebuilding a Interceptor motor.  Top end is off, pistons & replating are definitely in order.  I've already talked to Bob at Image.  I am hesitant to split the crankcase, but keep reading about the bearing & seal issues so I'm guessing it is inevitable.  I've already talked to a few of you guys out here and appreciate the help VERY much!  I though I would throw the post out here and see what comes in.  A couple pics showing quite a bit of grime on the mag side.  Thanks in advance for all your help!

[gixxer6]

Crank seals are an absolute must.  I'd pull the crank, change the seals, and inspect the crank/bearings.  If the crank needs work, I'd recommend Crankshaft Services http://www.jdsleds.com/ads/crankshaft/cs.html.

[Tory944]

  Hey, if the crank spins well (no rough bearings) good for you!  Otherwise, get yourself a good LTD crank (very similiar and it will work).  There has been some arguement in the past on outer seal replacement...  some say to put a light coating of grease on the inner lip (claiming a dry install my hurt the seal) and others say put it on dry.  I don't use anything...  your choice.  Do not put oil in the case!  DO lubricate the "crank bearings" w/2 stroke oil before assembling top half (including upper con rod bearings).
   As far as the case itself, I use a gasket shellac to seal up the case (looks like brown molasses).  Apply light on both case halves.  This was recomended by more than afew engine builders.  You want the case to seal well, but you don't want to use anything permanent (like JB Weld, ect.)  The idea is that if you need to open up the case again for any reason whatsoever, you don't want to beat it to death trying to get it apart.
   Upper end rebuild...  unless you have spare cylinders/heads don't do any porting!  If you feel brave you can remove some of the rough casting intake/exhaust ports and sharpen the intake "bridge", but I wouldn't take out too much material (messes w/port timing) IMO.
   Make sure everything is super clean, double check your piston circlips (make sure they "snapped" in the grooves completely, make sure piston arrow points to exhaust side, rings are in correct position w/no burrs... and on and on.
   There are alot of little things in two stroke engine building...  but those little things turn big after you pull the pull cord.  Double check yourself!  Good luck.

[jskal]

I dropped of my 550 Crank/Case to Jerome in Baxter this weekend.  Having him give it a once over & at a minimum replace seals.  I’m planning to send the cylinders off to Image soon, and get piston kits from him.  Tory, you mentioned the issues with the brass head gasket tolerances, do you have a good source for them?

Wanted to check with you and see if anyone's run flatslide Mikuni's on a 550?  Something like a rack from small block Polaris 40mm - any idea what the baseline would look like for that?

[gixxer6]

Does Image offer 550 pistons/rings again?  Last I knew, they were all out with no plans for more...  But I think they can still be had here: http://kawasakitrax.com/kawiforum/index.php?topic=199.msg997#msg997

[Tory944]

   Pretty sure Bob has afew sets left...  reworked jet ski pistons.

[gixxer6]

   Pretty sure Bob has afew sets left...  reworked jet ski pistons.

Ahh yes, I forgot that Bob had some jetski pistons done...  I was thinking of the pistons he had Wiseco make up for him years ago. 

Thanks for the reminder Tory!   

[Trucker]

Bruce Coffaro of JC Automotive in Rochester, NY  he had pistons made up and last i heard he had rings being made also