- Dec 6, 2014
That’s no worries, thanks Harley none the less! Jerry cleared it up for me. Thanks for sharing that info!
More expensive and less reliable than sticking with a points setup. I've been fortunate enough to have run across a complete crankcase with the points crank and supposedly good bearings on both sides. We shall see. If the cranks in those 045's have the cam lobe for a points ignition, they're definitely worth hanging onto along with the flywheels and any other points ignition components that may have come with those cases.
Coincidentally, I also happen to be doing a complete rebuild on an 048. The oil pump assembly itself from the 045 is a direct bolt on replacement for the 048 and several other saws of the era. There are different sizes of gears for different saws, but the pump is interchangeable.
I'm happy to see a thread where someone is bothering to check these clearances! I learned about the A B C sizing when I did my first 038 many years ago.On the piston issue...
My understanding is that the 'A' designation is generally the smallest of the three with 'C' being the largest -- relatively speaking. An AB piston is generally accepted as having an appropriate fit between an 'A' and a 'B' piston for either an 'A' or 'B' cylinder. Generally, a 'B' piston would be slightly oversized and not desirable for use in an 'A' cylinder, let alone a 'C' piston in either a 'B' or an 'A' cylinder. Conversely, an 'A' piston used in an already larger 'C' cylinder could potentially produce less than desirable performance results due to excessive clearances..., especially in an already worn 'C' cylinder.
Granted, the tolerances involved are small and may or may not affect a given application one way or another in any discernable way. On the other hand, and if tolerances are very tight, performance may indeed become an issue..., if not the fitment itself when a 'B' or 'C' piston is used in correspondingly smaller cylinders.
I'd like to learn how this is done. I guess if you can get the balls out you could put new replacement balls in (possibly higher quality), if the races were in good shape. Agreed if you can get a replacement not worth the effort. I've got a LOT of old equipment so the skill would be something useful for me. PM me if you have the time to explain this.You can totally dismantle the bearings to clean them up, polish the races and inspect each ball for pitting. Most won`t attempt it but it is possible.
Thanks mate! Much appreciatedI'm happy to see a thread where someone is bothering to check these clearances! I learned about the A B C sizing when I did my first 038 many years ago.
From Tom's measurements it looks like 0.10-0.13 mm/ ~ 0.004-0.005" clearance. A little loose but not terrible for a 40+ year old saw. Not sure what tools were used to measure things?
Like usual from Tom, great pictures, and some spotless top notch work, with attention to details, on a rebuild!!!
I'd like to learn how this is done. I guess if you can get the balls out you could put new replacement balls in (possibly higher quality), if the races were in good shape. Agreed if you can get a replacement not worth the effort. I've got a LOT of old equipment so the skill would be something useful for me. PM me if you have the time to explain this.
I've restored a lot of vintage bicycles from the 60s-70s with Campagnolo parts, but those bearings readily separate from the races. I've got boxes of record/super record parts........
I find the last version of MediaCAT (before it was revamped) provides the best method for Stihl parts lookups and cross referencing the 'where used' information.Not to derail the thread, but what are you using to cross reference part numbers between various saws that used the parts?
I tried this a while ago on a 385XP with very limited success. Ended up pulling it apart & using loctite bearing retaining compound. I pressed the bearing right up to the shoulder on the crank & I suspect that ended up being where the compound sealed it. Haven't run the saw enough to know if I can call it a permanent fix yetAnyway, as a possible solution before tearing everything apart just to scratch my head further, I'm trying a sleeve sealing method using one of the Permatex Green low viscosity wicking thread lockers to see what happens. Application number one made a significant difference after sitting over night, though it didn't completely seal the leak. I drew a very small amount of the retainer between the shaft and bearing using a MityVac hoping it would follow the vacuum and set up fairly quickly.
Pogo, if it’s just a small leak you can tune out, is it not best to leave well alone? I fear you’re opening a can of worms including side loading the bearings and possibly destroying seals?Excellent work. Well done!
I'm afraid I may have backed myself into a corner with the wicking compound. I do have two grades and used both. Progress was made overnight, but not to my satisfaction.
Now comes the part where we find out how strong it actually is as a bonding agent when I try to push the crank out of the case while leaving the bearing in place -- without destroying a NLA (or otherwise very expensive!) bearing. If excessive heat is required to break the bond, I can obviously kiss the seal goodbye and probably the bearing as well. 500F is specified.
I hope to get to it yet today.
It's been open. More like a bag o' snakes now. LOLI fear you’re opening a can of worms...