McCulloch Chain Saws

[vinnywv]

This is why bob never "split hairs" on the matter. Theres too many darn numbers and not much difference. Id say throw an 85240 or 69412 piston into that 7-10 and be done with it. Hes got them both. Just pick one or the other. Mac replaced 69412 with 85240 for some reason. We will never know why.

The 6-10 i have is the only 70cc saw ive got with that 3 finger transfer. The 2 7-10s have the open transfer and the pm700 and sp70 have the bridged one. As for pistons i know the 700 and sp70 have the same piston. The two 7-10s i dont know for sure and the 6-10 has 69412 in it. I hope all those numbers help.

 

[Jethro 2t sniffer]

It's worse than you think. Trust me. LOL

So I just ordered what appears to be Bob's last 69412 piston for the 7-10. Seems as though there's been a run on those and the 85240 lately. LOL Ordered the 85241 rings and a 65389 pin as well since everything points to the 69030 / 85239 piston using a different pin. My guess without measuring would be that it's just slightly shorter for the bosses in the windowed style piston. He has a shelf full of the later 85240's (which are essentially the same piston with slightly different skirt dimensions) that supersedes the 69412 if anyone was worried about availability. I just wanted to stick with what I've pretty much determined to be the correct parts for the purpose from all the obsessing and IPL rooting.

At any rate, we're gonna find out one way or another if the piston(s) situation has been the problem all along. I'm putting money on it since it has what is essentially a 5-10 / 6-10 three fingered transfer cast iron bore cylinder which calls for a full skirt piston, neither of which show up anywhere in any 7-10 IPL or on any of the piston and ring set lists I've seen for a 7-10.

Let's face it; Mark went way above and beyond with this saw doing everything under the sun trying to get it sorted out...., except changing to a full skirt piston. Thing is there, the prevalent consensus you read / hear these days says the newer 85239 thin-ring 2" piston is the miracle piston for all 70cc 2" applications regardless of cylinder type. Certainly no reason to think otherwise given such a prevailing opinion among most of the more experienced Mac guys out there, including Bob Johnson. And after all, an 85239 / 69030 was what was already in it when Mark acquired the saw. Who would just arbitrarily think of replacing it with a 'wrong' piston? No one..., 'cept maybe me? LOL

I'm certainly not casting aspersions toward Mark here and hope it doesn't appear that way. Quite the contrary. I'm simply theorizing a solution to a problem we were all trying to solve that he simply ran out of time to continue pursuing. He and Kevin already did all the heavy lifting. I'm just changing a piston to test what seems to be the last major theory not yet tried.

Can you guys believe it's been over a year since this saga began? I sure can. Boy, if it wasn't fun...!

I think it's a safe bet as like you say mark
went through it like a dozen times.

I wonder how long the 6-10L I'll call it was in production for if basically no document shows it existence.

I for 1 have enjoyed watching it pan out and have soaked in quite a bit of information.

 

[vinnywv]

Please send a video of this 7-10 running good when its all said and done!! Or atleast tell us its running or if nothing else lie to us...lol

 

[2broke2ride]

Please send a video of this 7-10 running good when its all said and done!! Or atleast tell us its running or if nothing else lie to us...lol

I certainly want to see it too lol!! With the time and money I put in it.

 

[Jethro 2t sniffer]

I certainly want to see it too lol!! With the time and money I put in it.

I hate to think what you sank into it but atleast you got a really reeeeealy nice 700 out of it and a nice 5-10 that came cheap

 

[2broke2ride]

I hate to think what you sank into it but atleast you got a really reeeeealy nice 700 out of it and a nice 5-10 that came cheap

You are right sir!!!! Although I will have a fair amount into the 5-10 as well. It is rough!!

 

[PogoInTheWoods]

The 7-10 will be documented for sure. Good, bad or upside down. Thanks for the additional numbers, Vinny. I've got a folder collecting all this stuff.

A 69412 piston, 85241 rings, and 65389 pin ordered as mentioned in the previous post. Bob still claims something else is wrong with the saw and an 85239 with thin rings supersedes everything else and should work fine. He didn't much want to hear about the different transfer design "hair splitting" today. Knew I just needed to cash out and be on my way at that point.

He did say these pistons have been generating quite a bit of interest lately, though. Sounded like a couple of em may be on their way to a new lab in Iowa for some top secret testing there, too. I told him it was all my fault and apologized for causing any trouble. LOL

 

[kbeck]

That's nice man really nice love the bar.

Did you chip off the last of the paint on the starter? I have 1 that looks dam neer identical the paint was just falling off so thought bugger it I'll make it shiny.

Yours has a falling sight on it that's cool didn't realize they had the sight and the logo thought the sight was only on the later plain ones.



Thanks Poge yes I'm spoiling it rotten lol

Strange having a new "best" saw in the mix the 800 held the trophy for a long time now it's sorta cast to the side a little.

The AV fix was a fiddly little job I've got some thick rubber somewhere instead of the four thin bits it will look a bit nicer but this is fine until then. I made them the total height of the gap between tanks so they can't turn around. Can also tighten or loosen the screws for a bit of tuning. Actually quite cool thinking about that.. aftermarket adjustable AV mount for long bars hahaha anyone want some?

Yes very nice saw sight must be on the handle. I just got a SP60 don't have it yet it was a e bay saw, wasn't looking for that saw in particular but wanted a 28 inch bar for the 800 this had one plus shipping was free to good to be true

 

[vinnywv]

I saw that one!!! If i hadnt bought that sp81 lot, that 60 wouldve been mine. Awesome bar on it. Congrats!!

 

[Jethro 2t sniffer]

You are right sir!!!! Although I will have a fair amount into the 5-10 as well. It is rough!!

Yeah it may be rough but that cylinder is good and that's the hardest part sorted.

 

[kbeck]

I saw that one!!! If i hadnt bought that sp81 lot, that 60 wouldve been mine. Awesome bar on it. Congrats!!

Thanks vinny Iv'e been looking for a bar/chain so it was easy to just take that off the price of saw then free shipping In 2200 miles it should be here. Should
wait till I get it but going to post a picture anyways

 

[Jethro 2t sniffer]

Thanks vinny Iv'e been looking for a bar/chain so it was easy to just take that off the price of saw then free shipping In 2200 miles it should be here. Should
wait till I get it but going to post a picture anywaysView attachment 798883

That's a good looking saw too

 

[Maintenance supervisor]

The 7-10 will be documented for sure. Good, bad or upside down. Thanks for the additional numbers, Vinny. I've got a folder collecting all this stuff.

A 69412 piston, 85241 rings, and 65389 pin ordered as mentioned in the previous post. Bob still claims something else is wrong with the saw and an 85239 with thin rings supersedes everything else and should work fine. He didn't much want to hear about the different transfer design "hair splitting" today. Knew I just needed to cash out and be on my way at that point.

He did say these pistons have been generating quite a bit of interest lately, though. Sounded like a couple of em may be on their way to a new lab in Iowa for some top secret testing there, too. I told him it was all my fault and apologized for causing any trouble. LOL

The way I think about it is if someone asked you for a 7-10 piston you got it! If I asked for a 6-10 or cp 70 piston well thats different?possibly?
Whether the C/P were left overs at the factory or someone swapped it out I would consider it mislabeling, its like looking under the hood of an early 80s Buick that has a 350cid,GM made 3 different 350s and anyone of them could be had in a Buick and if you arbitrarily ordered pistons with out casting numbers on the block well its any ones guess what you'd get.
I could understand why someone thinks this is "hairsplitting" when we say its a 7-10 , but really from everything thing I've read from you guys posts its not a 7-10 engine thats just whats on the fender.

 

[vizette]

Thanks for the comments, the bar is a 22" partner bar. I filed the holes out a tad. Pretty cool. Ive got another one on my pm700 that still reads partner on it. Theres a guy on ebay selling them. Pretty reasonable too.

The slot size is the same? Or did you have to use spacers on the studs? I thought the partner bars were larger (d009)

 

[kbeck]

The way I think about it is if someone asked you for a 7-10 piston you got it! If I asked for a 6-10 or cp 70 piston well thats different?possibly?
Whether the C/P were left overs at the factory or someone swapped it out I would consider it mislabeling, its like looking under the hood of an early 80s Buick that has a 350cid,GM made 3 different 350s and anyone of them could be had in a Buick and if you arbitrarily ordered pistons with out casting numbers on the block well its any ones guess what you'd get.
I could understand why someone thinks this is "hairsplitting" when we say its a 7-10 , but really from everything thing I've read from you guys posts its not a 7-10 engine thats just whats on the fender.

Got a pro mac 55 missing the hood will be wearing a 10-10 cover since that all I have for a spare. If I'm not around when its passed on the next guy may have a surprise hopefully a good one. Speaking of this saw got it as a parts saw had to tear it down to get a good look at what I had. When I pulled the tank off there was a washer between the tank and the oiler my pro mac 60 didn't have a washer. Pretty sure I should put one in when reassembly what is its exact purpose? Thanks

 

[Goinwheelin]

Got a pro mac 55 missing the hood will be wearing a 10-10 cover since that all I have for a spare. If I'm not around when its passed on the next guy may have a surprise hopefully a good one

That’s how I found my last 7-10.

 

[vinnywv]

The slot size is the same? Or did you have to use spacers on the studs? I thought the partner bars were larger (d009)

Right now its loose. Its a larger mount yes. I need to make a spacer for the slot. Ive made several im just out right now.

 

[Maintenance supervisor]

Got a pro mac 55 missing the hood will be wearing a 10-10 cover since that all I have for a spare. If I'm not around when its passed on the next guy may have a surprise hopefully a good one. Speaking of this saw got it as a parts saw had to tear it down to get a good look at what I had. When I pulled the tank off there was a washer between the tank and the oiler my pro mac 60 didn't have a washer. Pretty sure I should put one in when reassembly what is its exact purpose? Thanks

The old McCulloch dealer down the road told me that I absolutely had to put a washer between the oil and gas tank on reassembly or I could warp the tank and it would never seal, weather this is true or not I have know idea but its a pretty prevalent theory among the old guys around my area. Needless to say I also do this now and don't have any sealing issues.

 

[kbeck]

The old McCulloch dealer down the road told me that I absolutely had to put a washer between the oil and gas tank on reassembly or I could warp the tank and it would never seal, weather this is true or not I have know idea but its a pretty prevalent theory among the old guys around my area. Needless to say I also do this now and don't have any sealing issues.

Thanks easy enough to put one in why take a chance

 

[Goinwheelin]

My pro 10-10 had a felt washer between the tanks but there wasn’t much left of it so I made one out of delrin .062 thick. I didn’t want to use a steel washer because the tanks are a softer material.