McCulloch Chain Saws

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I am in the process of fully rebuilding my McCulloch 640 Chainsaw. I have an issue where I need to reseal the two piece gas tank.

Have any of you had success with any of the commercially available multi-step processes to strip, etch and re-seal/line the gas tank? How did you plug off the fuel outlet and/or cap (or did you)? Because it’s a two piece tank, did you work on the halves individually or together? If you worked on it together is there a way you did so without wasting a fuel tank gasket?

Your insight is much appreciated!
👊
Thanks!

Ive used both Red kote and a thin layer of jb weld.
 

edju1958

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Quick question guys. What is the bore of a super 550? I have a handful of 550's. One is a super. I am cleaning and sorting parts trying to figure which one is the super.
Jason,according to Acres' site,the 550 has a bore of 2.165 in.,but gives no specs on the Super 550 which is 4cc bigger.Sometimes Mac hadf the specs listed in the IPLs.I'll also emphasize that Acres' site is not always accurate.If you have them torn down,or have another method you could go through them by a process of elimination.Good luck!
 

knightmax

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I believe Red-kote is the method of choice around here, but I've never tried resealing tanks before. I'm curious to see your 640 rebuild as I'm currently in the middle of stripping down a 640 and prepping it for paint. The p.o. did a poor repaint using a rattle can that has since deteriorated from sun exposure so I really want to get it looking respectable again
The past couple years I have been using seal all on the two peice 10-10 tanks that have a gasket. It's been holding. I have not tired it metal to metal. I did a metal to metal on an 8200 with motoseal tank sealer. It was a bust. Not sure if the 640 has a gasket or not. Seal all being clear helps ascetics also. I use Red cote on the tank insides of all rebuilds now, it's good stuff.
 

edju1958

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I got a little more done on the 850 today.I fixed the switch wire.After looking at it a bit closer,I saw that the P.O.had put some type of plastic housing over the wire to protect it from grounding out against the special stud that holds the module in place.It would've worked real nice if he had moved it up more on the wire so that it could plug onto the spade on the module I had to cut that housing off & I bent the spade a bit & now there's plenty of clearance.I also thought that the tank boss for the bolt that screws in to hold the front handle was stripped.I turned the bolt in a bit more & all is well (so far).I was going to cut a chain down today too,but when I opened the bag of presets,that's all I got was presets,no tie straps.So much for ordering on Amazon,Lol.I didn't look at the pic that closely,I just read the description which said "25 Presets/Tie straps".I thought I was getting both,apparently not.I put some oil in the 850 & firerd it up on the 2nd pull to see if the oiler worked.It pumps out oil considerably.There's only one thing that's baffling me & that's the rear handle brace & how it connects to the rear handle.I'll need some ides on how to fix it.I'll get some pics on here tomorrow.
 

Jasonrkba

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Thanks Mark. I tore down another one today and the bore and piston looked great. After a good cleaning in the sink and flushing everything out with about a half can of WD Im confident enough that Im not going to remove the crank. I have two good ones so far one that ingested something pretty nasty and another I haven't touched yet.
 

Jethro 2t sniffer

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I got a little more done on the 850 today.I fixed the switch wire.After looking at it a bit closer,I saw that the P.O.had put some type of plastic housing over the wire to protect it from grounding out against the special stud that holds the module in place.It would've worked real nice if he had moved it up more on the wire so that it could plug onto the spade on the module I had to cut that housing off & I bent the spade a bit & now there's plenty of clearance.I also thought that the tank boss for the bolt that screws in to hold the front handle was stripped.I turned the bolt in a bit more & all is well (so far).I was going to cut a chain down today too,but when I opened the bag of presets,that's all I got was presets,no tie straps.So much for ordering on Amazon,Lol.I didn't look at the pic that closely,I just read the description which said "25 Presets/Tie straps".I thought I was getting both,apparently not.I put some oil in the 850 & firerd it up on the 2nd pull to see if the oiler worked.It pumps out oil considerably.There's only one thing that's baffling me & that's the rear handle brace & how it connects to the rear handle.I'll need some ides on how to fix it.I'll get some pics on here tomorrow.

Just reuse a tie strap from your chain Ed
 

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