My 20 MCS

[MCS]

I'd really like to fire this thing up but without a chain to cut wood it seems pointless. It hasn't run since '72 or '73, but there is nothing left of the 9/16" chain.
I took the bar and chain off last weekend to check the condition the sprocket and bar groove. The chain turned out to be #7 which is .050" gauge x 9/16" but I was expecting .063 gauge. Well, I'm quite sure Home Depot doesn't stock this size so I'm going to have trouble finding some.
OldZip sent me pictures and measurements of the 55593 sprocket that is used on a lot of the gear drives. It is a 1/2" pitch sprocket with 2 keys and the bore is 5/8". I was thinking I could maybe use this and convert it to 1/2" .050 gauge but that might not be easy to find either Well, the Super 1130G lists two sprockets - the 55593 and a 70353 which is .404. I can find 404 at 050. So this weekend I pulled the chain sprocket to find out what size the shaft is and it turns out it is 5/8" but............................
The sprocket is 5 pieces
The piece on the left is actually two items: The sprocket and the hub.

The sprocket is not pinned to the hub and spins freely. The pin in the picture is used to keep the brass washer from turning.

The brass "washer" mounts next to the sprocket, then the bevel washer, then the nut. So, depending on how tight you crank on the nut determines how much the sprocket can slip.

This whole arrangement must have something to do with the belt drive and protecting the belt from too much stress.
Does anyone have a 5-30N? It is a belt drive but newer than the MCS and LCS. If so, does the 5-30 have this same arrangement?
I don't have a 5-30 IPL but it is listed in the Third Eddition of the Homelite Dealer Service manual.
Does anyone have the above mentioned .404 pitch sprocket part number 70353?

[angel]

Could you convert the whole thing to use 3/4" harvaster chain? Man, if that thing bit into something it would take you for a ride!

[MCS]

I see the 5-30 shows both a 9/16 and 1/2" sprocket, but the sprocket shaft is a different part number. The MCS IPS shows all the above parts under one part number.
In the 5-30 picture is sure looks like the sprocket is keyed directly to the shaft.

[RandyMac]

Yep, keyed to the shift like most modern saws.

[MCS]

Gee, that's a real kick in the You're saying my MCS isn't modern? It has a piston, crankshaft, chain, bar, and operator just like all the other saws! And you have to mix oil in the gas!!

[RandyMac]

Ok ok, it's not old, just different. I'll hit up an old Homelite guy. maybe find you a good sprocket.
10 to 1 30w rocks, if you have not tried it, do it at least once.

[MCS]

Randy, it's not so much the sprocket, it's that I need a chain to match the sprocket too and the chain has to be .050 to match the bar. Hummmm, maybe it isn't so modern now that I think about it. But what is even worse, it could have been built about the time I was born

[MCS]

Speaking of 30wgt oil and gas mix. In 10th grade I built a small scooter in metal shop. Sure got good at braising EMT. I found a 2 3/4HP 2 cycle Clinton engine for it and had to mix the fuel at 16:1. It smoked some but once warmed up it wasn't that bad and I could do 30 mph so I left all that smoke behind anyway.

[billg]

a7ecorsair

I have a lot of old Homelite gears but not a 1/2" in that arrangement. The majority used a double keyed 0.625 bore. I do not have a 20MCS here to look at but I would imagine you could use one of the double keyed gears.

As for a .404 they are tough to get. I can have them made at $55 each when I get a big enough order but I doubt I will ever get enough guys to make an order of 25.

You said you could get .404 .050 chain. I need some so if you run across extra let me know.

Bill