MCCULLOCH The official McCulloch thread

[edju1958]

Yeah,I've never heard of the Mac Pole Cat either.I wonder if marketing knew that it's another name for a skunk,Lol.

 

[the 28inch mac man]

I think I've got one of Ryan's 3D printed ones at the ready if you want to try it...

Pm sent.

 

[palmetto state macs]

My problem? Solved.

 

[heimannm]

I can virtually guarantee that you will never see another Pole Cat saw. One of a kind.

Mark

 

[the 28inch mac man]

Does anyone know what a mcculloch 65785 block would be from?

 

[the 28inch mac man]

Also will a sdc 18 work in place of a sdc 19 for a 795?

 

[heimannm]

Not sure about that block number.

The SDC 18 requires an external idle speed screw like you find on many of the 10 Series saws. The SDC 19 has the idle speed screw built into the body of the carburetor.

Mark

 

[the 28inch mac man]

Not sure about that block number.

The SDC 18 requires an external idle speed screw like you find on many of the 10 Series saws. The SDC 19 has the idle speed screw built into the body of the carburetor.

Mark

Thanks for the info, do you think sdc 18 will have enough fuel for a 795? I can deal with the idle screw easy enough.

 

[heimannm]

The throttle bore and venturi are the same on the 18 and 19.

SDC16 and below are smaller (.750 and .625), 18 and above are larger (.812 and .750).

Mark

 

[Sloa]

Evening, question about timing and detonation. Attempting to get fuel to pull from tank and about done with this flat back.

A problem I’m having is detonation of left over fuel while attempting start. I feed a healthy tablespoon or so in carb and off to the races the saw goes, but as I’m still fighting with carb it just runs itself out. Now though I run the risk of flooding if I just keep feeding it so give another pull to ensure all used up or even prepping for next pull saw will detonate with slightest of upward motion with not enough fuel stops dead or reverses and pulls into starter, not pleasant on arm or starter.
I have points set at .1500 . I ran two tanks through before I buttoned it up .

 

[the 28inch mac man]

Evening, question about timing and detonation. Attempting to get fuel to pull from tank and about done with this flat back.

A problem I’m having is detonation of left over fuel while attempting start. I feed a healthy tablespoon or so in carb and off to the races the saw goes, but as I’m still fighting with carb it just runs itself out. Now though I run the risk of flooding if I just keep feeding it so give another pull to ensure all used up or even prepping for next pull saw will detonate with slightest of upward motion with not enough fuel stops dead or reverses and pulls into starter, not pleasant on arm or starter.
I have points set at .1500 . I ran two tanks through before I buttoned it up .

Your deffenatly not pulling fuel. You mite also have a air leak. I went through this myself back in the spring with a 440 (baby 797). I could not get the saw to pull fuel for any thing with 3 different carbs. It ended up being a vacume leak. As far as the kick back is conserned, with these saws you have to set the points based on timeing. You can still buy the mac timing indicator(a little lot that mounts on the crank) on ebay. The chainsaw guy on youtube has a great video on seting the timing on a sp125 which should be the same setup.

 

[Sloa]

Your deffenatly not pulling fuel. You mite also have an air leak. I went through this myself back in the spring with a 440 (baby 797). I could not get the saw to pull fuel for any thing with 3 different carbs. It ended up being a vacume leak. As far as the kick back is conserned, with these saws you have to set the points based on timeing. You can still buy the mac timing indicator(a little lot that mounts on the crank) on ebay. The chainsaw guy on youtube has a great video on seting the timing on a sp125 which should be the same setup.

Thanks for the reply. I have watched and employed setting the timing by multi meter and tone. I will give a double check to make sure nothing has changed. Will also try .1600 and as much as .1800. I have utilized what I believe to be a 440 tank and filled in intake to match 797 tank. Would gas cap with faulty valve cause vacuum leak? Have to caps and one new valve,one cap is for older big saw style ,which I prefer . I don’t put sealer around carb intake just gasket, in this particular case is it worth the effort. The old diaphragms were able to draw fuel two months ago but looked a little rough so also picked up kit with same result. Would benefit from fuel line change , possibly air leak as I have line stuck in larger line near inlet as having hard time finding replacement to fit.

 

[the 28inch mac man]

Thanks for the reply. I have watched and employed setting the timing by multi meter and tone. I will give a double check to make sure nothing has changed. Will also try .1600 and as much as .1800. I have utilized what I believe to be a 440 tank and filled in intake to match 797 tank. Would gas cap with faulty valve cause vacuum leak? Have to caps and one new valve,one cap is for older big saw style ,which I prefer . I don’t put sealer around carb intake just gasket, in this particular case is it worth the effort. The old diaphragms were able to draw fuel two months ago but looked a little rough so also picked up kit with same result. Would benefit from fuel line change , possibly air leak as I have line stuck in larger line near inlet as having hard time finding replacement to fit.

I ment a vacume leak in the crankcase not tank. Does your saw have new crank seals?

 

[Sloa]

I ment a vacume leak in the crankcase not tank. Does your saw have new crank seals?

Sorry, yes replaced originals earlier in summer. I do not believe there is a leak around seals saw does not behave in that manner. I will attempt one more try once I fix fuel line and really seal carb gasket. After that if it still is a no go will change carb. Took a week of trial and error to get it to draw fuel before I sealed it up. But really liked the response , wish it would behave.

 

[the 28inch mac man]

Sorry, yes replaced originals earlier in summer. I do not believe there is a leak around seals saw does not behave in that manner. I will attempt one more try once I fix fuel line and really seal carb gasket. After that if it still is a no go will change carb. Took a week of trial and error to get it to draw fuel before I sealed it up. But really liked the response , wish it would behave.

When my saw was acting like that it ended up being a air leak. It wasn't pulling fuel because there was no pulse. The saw would even fire and run on prime.

 

[the 28inch mac man]

Sorry, yes replaced originals earlier in summer. I do not believe there is a leak around seals saw does not behave in that manner. I will attempt one more try once I fix fuel line and really seal carb gasket. After that if it still is a no go will change carb. Took a week of trial and error to get it to draw fuel before I sealed it up. But really liked the response , wish it would behave.

If you decided as I have that you are done with the flat back carbs you could always make a adapter to put a sdc on it. I'm in the prosess off making one out of some aluminium plate for my 795. When I finish I will post some pics.

 

[heimannm]

Check the needle and seat. Some of the modern fuel constituents will cause the older rubber seats to swell and prevent the needle from passing fuel.

I've run into that a few times in the past 2 or 3 years.

MAC carburetor would work fine when I put it together and run the saw, a few days later no go...

Mark

 

[Sloa]

Check the needle and seat. Some of the modern fuel constituents will cause the older rubber seats to swell and prevent the needle from passing fuel.

I've run into that a few times in the past 2 or 3 years.

MAC carburetor would work fine when I put it together and run the saw, a few days later no go...

Mark

Okay, emptied earlier to bring inside, I’ll take a good look and post a few pics. A issue for myself is this is the first and only carburetor like this I have ever seen and played with. You may tell me I have up from down and it would be welcomed.

 

[Sloa]

Impulse hole clear, carb gasket lines up. Should I use thicker gasket material?

 

[Sloa]

Found a fleck of yellow in the inlet. That was obvious, but I don’t see anything else amiss. Also have new kit, but thought if I’m fighting with the dam thing I’ll use up the old set.