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)?

That looks grim Trouts. 

You might want to keep parts from the engine such as exhaust, carb, head, crank etc. but by the looks of the piston and your description of the cylinder, those components are shot.   Looks like the engine was "straight gassed".  Shame.   As a rule, they're very rugged engines. 

I wonder if a Tecumseh two stroke can be dropped into that thing?  Might have to review the engine mount bolt hole pattern and alignment of output shaft to the paddle drive.   I'd have no hesitation to use a Tecumseh two cycle engine.  From my experience with them, I'm quite impressed.   A used MTD/Murray SS from the 90's would be dirt cheap to buy just for the Tecumseh engine. 

By the way, all two cycle engine have needle bearings on big end and small end of the connecting rod.  A plain bearing wouldn't survive with the limited amount of lubrication available. 

Theres a guy on EBAY that has RTEK short blocks and full engines from $200 and up. The name of the vendor is Chicago Lawn Mower and Snow Blower. Marc

I bought a very lightly used 2005 MTD SS machine with a Tecumseh engine in it for, I think. $90.00.  Woman I bought it from said it stopped running the second year she owned it so she left it in the shed and her husband shoveled the driveway.  Understandable.  The driveway was barely big enough for a car and a half.  Hardly a need for a machine.   I pulled the float bowl off and found a chunk of ice big enough to keep the float bowl suspended.  No gas, no fire, no use.  The thing looks new. 

The only reason I bought it was for the engine.  I figure that if I blow the engine in the Craftsman, I'll have a back up on hand.  Meanwhile, the MTD is parked on the deck to keep it clear. 

I can't believe how nicely those Tecumseh two strokes are.  After sitting all spring/summer/fall, I added gas, primed a couple times, engaged the choke and one pull on the rope.  They both fired right up and ran nicely. 

Mml14,

   I tried to get to the Chicago Lawn Mower and Snow Blower site but it’s broke.  A short block would be too expensive but I wanted to see what they offered.

 

Borat: “A plain bearing wouldn't survive with the limited amount of lubrication available”

   So that’s why they have needle bearings.  Maybe the needles instead of $#%* due to space? 

      Your right, it looks pretty grim.  It would be about $140 in parts and given the condition of the bore not an assured success for the effort.  It's a great parts machine though.  I’ll be trolling for 3650 someone’s backed their car into or cobbled up a tree limb and mushed the auger. 

 

    BTW: I sold off the 2450’s I had and picked up a very nice 3650 for $75 to use for the season.  The auger engagement lever was limp.  The engagement spring buried in the base was broken.  The guy sidelined the machine for a few years in parts after he gave up fixing it.  He also left the gas in so the carb was loaded with a thick blue-green jell from evaporated gas and oil.  This will give me a slightly larger hp SS to try out this season.

Did you check to see if a 139cc  HSK850 Tecumseh will fit?  I checked out some Toro PDF files and they used Tecumseh engine in the 90s.  Might be a chance to drop one of those in to replace the R-tek if you come across a used MTD/Murray machine dirt cheap.  

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