I don't know much about the older ones other than some had bronze bushings instead of bearings.
Nice , actually pristine for a high hr engine . Amazing that such little damage to the piston crown & skirt after sucking in the reed . Theynreakly thrived on the old OMC oil technology . I use to due a carbon inspection & muffler decarbonizing every 2 yrs of service , just routine maintenance back then likely only 200 hr. frequency max . Never effected performance !
Yep , exactly . The older series used a composite brass / bronze Babbitt material bearing ( bushing) . Low tech but serviceable for the day . That's why oil viscosity was crucial . I still run my old girls yearly on the front lawn portion of my acreage for sentimental reasons !
I never tore into that one until it died on me one day and wouldn't start normaly or stay running for more than a few seconds. Drove me crazy trying to figure out why. I ended up pulling the carb off to try swapping carbs when I noticed my reed valve motor turned itself into a piston port. I had intended to replace the motor with a Toro Rtek, which is a piston port version of the same motor which makes a bit more HP. Never got around too it and ended up hauling the thing to the dump. The duraforce models where no where near the quality of the older ones and I worked on several duraforces for 20 years. Grew sick of it and bought a Honda 4 cycle.
Sentimental reasons are the only reason I got involved with lawnboys in the first place. I first started mowing with a lanwboy.
Reed valve to piston port , Roflmao ! Had a R-tek in a Toro snowblower early 80' s I think . Performed well , matched the Tecumseh Snowking I had at the time for driveway usage .
Best engine lawnboy ever put in a mower , the injector system was troublesome & sketchy at best . As I said previously converted to Premix & still run my "M" series to this day , I have had to modify or adapt blades which is frustrating . Hard to find own up North here ! P.S. sentimental yes , my lawnboys & my Harleys !
The last lawnboy I bought, the one pictured above that had the read failure was purchased out of Winnepeg when I lived in NW Ontario. It was one of the last ones in Canada.
This wpuld be a different Rtek. They were only sold for around 10 years before being discontinued due to emmissions regs. Basicly they where a lanwboy motor minus the reeds with more radical porting so they made 8hp.
8hp Performance Class , special order option for the Toro snowblower . Yes believe it also had a high peak operating rpm also , likely due to the more radical porting / tuning . I just remember the advertisement banners at the Toro Dealer " New Retek high performance Engines" I think the actually Tech Specs mentioned Briggs 5.5 hp , so perhaps a different 2 stroke ?
I saved a lot of the early engines by making a replacement bronze bushing on a lathe and boring the case on the mill and pinning the bushing in place. Never lost one due to bushing failure/spinning
Yes, two different motors.
It's a shame one could just adapt them to ball bearings. Much better setup.
There wasn't really enough meat in the case to bore it for a ball bearing assembly. I considered a needle bearing setup but didn't know if the crankshaft steel was of sufficient temper to allow direct contact with the needle bearings. A bronze bushing is long lived if it has a sufficient and correctly placed groove in it to carry lube to the bottom of the bushing.
Probably could reverse engineer mechanically , although oil delivery
After fitting the bushing I used a double lip seal. IIRC, I had to bore the seal recess slightly deeper and larger in diameter to fit the double lip seal. The garter spring prevented oil leaks from the bottom of the crankshaft and relocated the outer seal lip to an unworn area of the crankshaft. OE used one groove in the bushing, IIRC, I used three narrow grooves. It's been a few years since I've done any.
