troutfisher
Addicted to ArboristSite
So, what mix were you running?
I'm concerned about Andy though.....he didn't blow his top at my trolling
Would a later 028 Super have the same issues of the bearing cages becoming brittle due to straight gas overheating? I am rebuilding one that looks to be very low hours, but had a toasted piston and you could smell the stale straight gas in the tank. This is a side adjust model, likely a very late one.
Does this constitute an attenmpt to hijack a thread? I don't mean to.... seems related. I never thought there would be plastic bearing cages in a saw. or bakelite or whatever composite it is....
litefoot: The mashed ends on the ignition can be a problem - the laminations are actually insulated from each other to stop eddy current losses. Best way to know to try it though.
teachergirl: No saw is immune to cage failure. Age, heat and gas additives seem to affect some of the plastic (nylon) cages but in general they have lower friction and less ball wear. The riveted steel cages don't fail as easily, but don't have as long a life in the lower ends, particualry in high reving saws. The pressed steel cages that are spot welded suck... Never put these in if you use generic bearings.
Well, I replaced the bearings and oil seals and gasket on the 440 following the service manual and tips from all you good folks here at AS. I then pressure/vac tested the saw. Both failed.
Just so you know, I bent up one of the circlips, so I tested w/o the piston (jug bolted down over the connecting rod) until I can pick up a circlip. Cylinder head screws and case screws were torqued to spec. The spark plug is tight and the decomp appears to be sealing well. And the intake and exhaust test seals appear to be solid.
The gauge drops from 7 psi to 0 psi in about 1.5 minutes, so it's a bad (audible) leak. But without removing the FW and clutch, it's kind of hard to identify. My guess is the clutch-side seal because I hear a faint "bubbling" on that side.
One caveat, I diverged from standard procedure with the seals. When I picked up the seal/gasket kit from the dealer, he stated that two-stroke on the rubber would be fine (instead of grease). Would that cause a sealing problem, or is that more for long-term durability? I was very careful to not seat the seals past flush with the bearing races.
I always use 2-stroke oil on new seals. That's what will lube them for the rest of their lives.
I know you said you had everything tight but can you pin point the leak? Maybe pump it up and spray some water/soap mix in the questionable areas, any leak will show with bubbles.
silly question(?) can the crank develope a groove from the seal?
i know you said you had a low hour saw but could there have been a little grooving?
2K, I haven't removed the FW or clutch yet to check. But I will.
Glad you got it all apart, you'll be happy when you put the new bearings and seals in. You'r problem could have been leaking case seals, but replacing them is a good way to make sure that doesn't happen again anytime soon.
The crank bearings are around $50 for both OEM, plus you'll need a gasket set for another $20 or so and you'll be in busines.
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