McCulloch Chain Saws

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heimannm said:
Gary, a while back there was a pretty good thread on the Tillotson HL, perhap you saw it and forgot it was out there?

Seems to me the guy putting it together was content to switch out the metering levers rather than adjusting the height. You might have some success controlling the leakers with the metering lever set correctly. I haven't had to mess with an HL lately but I suspect they should be level with the carburetor body like the McCulloch carburetor. One thing I try to do when adjusting the lever is avoid prying it up against the needle in the seat, pry both sides to prevent jamming the needle into the seat and damaging the seat. The seat in the HL is replaceable.

I have a couple of HL leakers as well, both the needle and seats are available individually and I seem to have the best luck changing one or the other, rarely have to replace both to fix the leak.

By the way, the HL leakers are on Homelite saws, I don't seem to have many problems with the HL equipped McCullochs.

Mark
Click to expand...

Thanks Mark... I actually changed the levers this time... just because. Hmm... I adjusted them level with the metering body. So Imma scratchin' my head.

Guess I gotta tear 'em back apart and adjust them. Never had to readjust. Not sure which way to bend the tab if it's already flush. Weird.

At least you don't have to tear the rear half of the McCullochs apart to get the carbs out like you do most Homelites. :)

Gary
 
leeha said:
Gary, Are the fuel tank caps venting ok.
You don't want to much pressure in the tank.
The carb needle and seat might be leaking.
Wipe the entire air box and carb clean and
watch it to see where the gas is coming from.
Throat or between the body housing and plates.
I personally don't like the newer fuel pump diaphrams.
I have had them leak. I prefer the older black rubber
ones.


Lee
Click to expand...

These are the newer non-rubber ones Lee... figgers. :laugh:

On the 640 the cap has to be loose to run... maybe I'll switch caps. The 640 leaks waaayyyyy worse than the 795.

Gary
 
Most of the McCulloch fuel tank caps have a duck bill valve (53766) that vent the tank when pressure is low and hold pressure in the tank when it warms up. They do get pretty soft and gooey after a while, someone described the condition as turning to whale snot. I suppose it is possible that they seal too well in that condition and don't vent initially then cause too much pressure to build up once the saw is warmed up.

I think Bob Johnson sells them for $6 each.

On the Tillotson leakers, I was successful stopping a leak here and there just by flipping the seat over.

Mark
 
heimannm said:
Gary, a while back there was a pretty good thread on the Tillotson HL, perhap you saw it and forgot it was out there?

Seems to me the guy putting it together was content to switch out the metering levers rather than adjusting the height. You might have some success controlling the leakers with the metering lever set correctly. I haven't had to mess with an HL lately but I suspect they should be level with the carburetor body like the McCulloch carburetor. One thing I try to do when adjusting the lever is avoid prying it up against the needle in the seat, pry both sides to prevent jamming the needle into the seat and damaging the seat. The seat in the HL is replaceable.

I have a couple of HL leakers as well, both the needle and seats are available individually and I seem to have the best luck changing one or the other, rarely have to replace both to fix the leak.

By the way, the HL leakers are on Homelite saws, I don't seem to have many problems with the HL equipped McCullochs.

Mark
Click to expand...
I was just getting ready to post to this thread when I read this: I got my 1-42 running today. It really does well and after I adjusted the carburetor it starts fairly easy and really sounds powerful. It's got a problem though..it has fuel in the carb box also but I think I know where mine's coming from. It looks like someone put too big a fuel line from the tank to the carb then tried to squeeze it down with a clamp. It's really wet where the line goes to the carb. I wonder what I'm getting myself into if I try to change the line. Do I have to take the tank off or anything? It's the line going to the outside of the tank from the airbox and carb. I haven't looked closely, when I saw it filling up I drained the tank and quit on it for the day. I'm glad I got it running though!
 
It is possible to replace the fuel line without taking anything off, you just have to work at it a bit. Probably easier to remove the carburetor and install the tank end first then the carburetor end as you replace the carburetor.

On the older saws the fuel line had quite a large OD that helped seal it through the air box, later lines had a sort of molded grommet that would seal where the fuel line passes through the air box. Though the "clamp" was just a simple circle of wire (50742) , it really does help to seal the fuel line on both ends.

If you have to go the route of modern fuel line, you will need to install a grommet where the line goes through the air box to insure a good seal, or expect to get a lot of sawdust in there if you cut with the saw.

Mark
 
heimannm said:
It is possible to replace the fuel line without taking anything off, you just have to work at it a bit.

On the older saws the fuel line had quite a large OD that helped seal it through the air box, later lines had a sort of molded grommet that would seal where the fuel line passes through the air box. Though the "clamp" was just a simple circle of wire (50742) , it really does help to seal the fuel line on both ends.

If you have to go the route of modern fuel line, you will need to install a grommet where the line goes through the air box to insure a good seal, or expect to get a lot of sawdust in there if you cut with the saw.

Mark
Click to expand...
I've got a bunch of grommets that probably will work. I intend to use a smaller fuel line than is presently there. If the grommets are the wrong size I'll probably use some RTV to close the gap. The clamp that's on there now isn't the circle type, it's the kind with the screw tightener, sorta automotive type. I'm pretty sure that's where the fuel is coming from, he's probably split the fuel line with that clamp. I've got a rear handle bottom piece coming for that saw..just doesn't look right without it IMO. I think when I get this saw ironed out a little more I'm actually gonna try to cut some firewood with it!
Oh, what size file do I need to sharpen that chain? I think I'll have to buy one; the files for my little saws probably won't work on this chain!
 
GASoline71 said:
Mark, Lee, Randy, Jacob... I am going bat#### crazy tryin' to figger out why my 795 and my 640 constantly fill the air filter/carb box up with fuel. Bigtime leaks... both saws have rebuilt HL's and new fuel lines... The 640 just now had dang near an inch of premix in there... :censored:

Gary
Click to expand...

I have been having the same problem. Mine was pouring from the carb throat. A couple of pulls with the cover off the air box and you could see it pour out the throat. And I am thinking its my seat is bad. But that is how I found where the fuel was coming from, by removing the air box cover and trying to start it.
 
heimannm said:
Most of the McCulloch fuel tank caps have a duck bill valve (53766) that vent the tank when pressure is low and hold pressure in the tank when it warms up. They do get pretty soft and gooey after a while, someone described the condition as turning to whale snot. I suppose it is possible that they seal too well in that condition and don't vent initially then cause too much pressure to build up once the saw is warmed up.

I think Bob Johnson sells them for $6 each.

On the Tillotson leakers, I was successful stopping a leak here and there just by flipping the seat over.

Mark
Click to expand...

Mark... I just got off the phone with Randy... we were discussing that very thing. The only time they leak is after i shut the saws off, and they sit for a spell... Thinkin' it might be a little of the seat, and a little of the cap...

Thanks for they help fellas!

Nowthen... whose the idjit that did the HL thread? :laugh:

Gary
 
Meh... gascaps... schmashcaps... stupid gascaps... with the cap loose... no leaky... 795 is the same way...

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Gary
 
Had a couple of minutes to play with the 77 before doing the brakes on the Wife's car today. Primer actualy worked (a bit), and it fired on its own without sprayin' mix down the throat. Carb's still acting sick, but may well respond to a good disassembly and cleaning. I had let it sit for a week with mix in it that contained quite a bit of sta-bil. Maybe that softened some crud...:givebeer:

The fuel in the tank (which was fresh mix poured into a totaly empty tank last week) now looks kinda 'varnishy', like the mix dissolved a buncha crap in the tank and felt filter pad. Gonna drain it and start anew. Crossing my fingers and hoping I don't have diaphragm troubles. Man that saw sounds awesome. 7.3ci of 53-ish year old Mac fury...:cheers:


Oh..............and speaking of gascaps..............The cap on the 77 has no rubber check valve at all anymore. Just a big gaping hole in the middle, and an extension on the inside that once held a check valve. Guess I need a check valve or another cap too...
 
Last edited:
One more thing.......







Haven't measured the chain on the 77 yet to determine whether it's 1/2" or 9/16". Acres site sez the 'early production' 77s were 9/16", while 'later production' 77s were 1/2". By my callibrated eyeball, the chain looks bigger than 1/2". I'll know for sure once I measure three and divide by two. Anywho.................what files are used to sharpen 1/2" and 9/16" chain? Biggest I have right now is 7/32"...
 
Eccentric said:
One more thing.......
Haven't measured the chain on the 77 yet to determine whether it's 1/2" or 9/16". Acres site sez the 'early production' 77s were 9/16", while 'later production' 77s were 1/2". By my callibrated eyeball, the chain looks bigger than 1/2". I'll know for sure once I measure three and divide by two. Anywho.................what files are used to sharpen 1/2" and 9/16" chain? Biggest I have right now is 7/32"...
Click to expand...

count the drive links in a 12" span. 1/2 has 12 dl and 9/16 has 11

1/2 uses 1/4 files and new 9/16 takes 9/32. worn down 9/16 can use 1/4 file
 
RandyMac said:
I ran your vid twice Gary, just to hear you laugh at the end.

I have seen NOS caps, now I need to remember where.
Click to expand...

I love how the dog's totally unfazed. Critters and neigbors ordinarily scatter on the wind when I start a saw.
 

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