Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Discussions

   Picked up a CCR3650 for $40 that a dealer tossed in the towel on.  It's a 2003 model 38518 and has the R-Tec 141cc engine.  The externals were ok and the engine not frozen so picked up as a possible resurrection or worse case a parts machine.   After taking it apart and looking it over it seemed it would cleanup fine so the only issue was the engine. 

   It had spark but would not start and the compression very.  The electric start gear was stripped but the flywheel teeth ok

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   Took out the engine that seemed very small.  Hard to believe it’s 6.5hp.  It looks like it should go on a model airplane.  Opened the engine and to my surprise the crank was on roller bearings.  Odd was there is no part number for the bearings.  The crank is sold as an assembly with bearings.

   Opened up the engine and found the piston in pretty bad shape, with heavy scoring from top to bottom, especially the bottom which is very bad. 

   On one side the rings are stuck solidly in their slots and the wear such that the rings can’t be distinguished from the piston body.  The bore above the ports has lines but seems smooth.  I can’t catch a fingernail but can just barely feel them and guessing a few might be .0005 or less. 

   Below the ports is another story.  There’s deep lines and rough places.  The question is what are the chances of success with a rebuild?  The piston top will ride down to the top edge of the ports where the bore is in ok shape.  I think the piston would probably go down to where the bottom ring is just above the port. 

    The bottom of the piston skit would be at the same level as the bad scoring on the bore.  The bottom bore scoring will probably rip up a new piston skirt quickly.  Can that be lived with or will damage to the skirt cause problems?

   Another question is has anyone put in a different engine into one of these bodies (38518)?

Trouts,,

l ve rebuilt some engines that have looked similar to this one with pretty good results... the piston is rough..can u get a new one?? if not ive have sanded them down smooth with emery cloth..and for the cylinder bore i would use a cylinder hone to smooth it out..but make sure u use lots of engine oil while honing and only take off the bare minimum needed to make it reasonable smooth.. there will be still be some gouges there but thats fine... the piston is rough if u can get another one cheap then i would go that route...but most likely not... just make sure the new piston rings move freely in the piston grooves that very important... and if there tight just take a small file and widen them slightly so the rings move freely.. i have used a finger nail file to do that if u dont have a small enough file to do so..

 i would bet money that it will run good afterwards...know longevity is another thing(worst case is the piston rings wear a liitle quicker)...although i rebulit my nieghbours 2.5 years ago and did just as i mentioned and its still starts first pull...

i see this come into the shop alot...and its a good way to diagnose internal engine damage...becuase i would bet this engine was flooding out like crazy... that coupled with the low compression... if u ever get a two stroke motor in that wont start and u pull the plug and its wet.. and u you've changed the carb kit... then 90% of the time on the exhasut side the rings are welded to the piston and fuel justs blows right by rings filling the crankcase and in turn causing an extremely rich mixture (flooding the plug).

trouts2 wrote:

Trouts- Try these EBAY auction #'s-#330424728290 and # 390246703992. A little pricey but new is neat!! Marc