McCulloch Chain Saws

[rwoods]

Well, today made up for last Saturday. I was asked to help cut up a nice old red oak. It was kind of shameful to cut it for firewood as it had a nice veneer quality log about 3 1/2' in diameter. I used "Ric" today. Ric is my 125C with the 36" bar that I named after Sawbones who sold it to me - my first 125. As some of you know it was a little anemic when I got it but after I removed the clogged muffler screen it was really strong. I later replaced the whole muffler with a little GEM kart muffler. I am still amazed that I can bury it nose down and lean on it with both hands and it just keeps cutting.

As usual I have a MAC question: After running several tanks through Ric, it began to splutter and would almost backfire under WOT. I shut it down, pulled it over to make sure it wasn't about to seize - it immediately cranked up again. So I kept on running it. In a few minutes it cleared up and ran perfectly as before. Any thoughts? It scared me a little as it sounded like by PM 800 as it died. Ron

Ric is on the left - middle shelf.

 

[homelitejim]

Well, today made up for last Saturday. I was asked to help cut up a nice old red oak. It was kind of shameful to cut it for firewood as it had a nice veneer quality log about 3 1/2' in diameter. I used "Ric" today. Ric is my 125C with the 36" bar that I named after Sawbones who sold it to me - my first 125. As some of you know it was a little anemic when I got it but after I removed the clogged muffler screen it was really strong. I later replaced the whole muffler with a little GEM kart muffler. I am still amazed that I can bury it nose down and lean on it with both hands and it just keeps cutting.

As usual I have a MAC question: After running several tanks through Ric, it began to splutter and would almost backfire under WOT. I shut it down, pulled it over to make sure it wasn't about to seize - it immediately cranked up again. So I kept on running it. In a few minutes it cleared up and ran perfectly as before. Any thoughts? It scared me a little as it sounded like by PM 800 as it died. Ron

Ric is on the left - middle shelf.

maybe it just got hot and started to vapor lock, or some debris made it into the carb. Good to hear it cleaned up and kept cutting.

Edit. maybe a drop of water in the fuel?

 

[rwoods]

maybe it just got hot and started to vapor lock, or some debris made it into the carb. Good to hear it cleaned up and kept cutting.

Edit. maybe a drop of water in the fuel?

I wondered about that as I had just run it completely dry and refueled. Maybe I'll get to run it next week on the other large oak I have down; if so, I will report back. Thanks, Ron

 

[mweba]

Add some inside shots in this thread.


100_4958 by mweba1, on Flickr


100_4957 by mweba1, on Flickr


100_4959 by mweba1, on Flickr

Balanced piston sleeve.

Bp-1 balanced piston sleave by mweba1, on Flickr


Bp-1 cylinder by mweba1, on Flickr


Bp-1 crank by mweba1, on Flickr

 

[mweba]

Turn the volume down if you'd like to avoid the rambling commentary

[video=youtube_share;WhJ4ACYzVSE]http://youtu.be/WhJ4ACYzVSE[/video]

 

[heimannm]

A little different BP

Mark

 

[heimannm]

I did not take any photos today but I did slip across the alley this afternoon with one of the PM800's and finished off a stump the neighbor had been whittling away at with his newly acquired Wood Shark. The fact is I cut the tree down a few years ago but left about 6-8" above the ground at the time. The new property owner wanted to knock it down to avoid issues when he runs his snow plow over that spot this winter.

This was the least impressive of the three I have, and I will say that even that one is pretty strong. Since it is equipped with a half wrap handle it is a bit more useful when flush cutting stumps.

You can see the stump sticking up behind the pile of smoldering scraps; that photo was 28 November, 2009.

Mark

 

[OldDeadWood]

Bp-1 ?

mweba or Mark H.

Does it seem that the weight of the BP-1 balance piston and rod are the same as the main piston and rod, even though the balance piston is much smaller.?

Also does it look like this, two piston, system could be super charging the motor at a rate higher than atmospheric? The piston port seems to be in an odd place.

I know that these saws were capable of over-reving the other saws of that period and i'm wondering if there is more to this than just the balance of the two pistons.

Thanks for the look into this intreiging saw and please show more.opcorn:

ODW

 

[rwoods]

Mark, any specs you could share on the twin would be appreciated. Also any info on why this too didn't survive. Thanks, Ron

 

[jhoff310]

ok guys I am looking for some info...
I need to know what is the difference between a 3-25 Early VS a 3-25 late?

Also looking for an IPL for a 10-10 and the 3-25 if there is one

picked them both up early this year in a lot of 8 saws for $100...3-25 runs, needs some tweaking...10-10 runs like a raped ape..great running saw

Thanks in advance

Jeff

 

[homelitejim]

ok guys I am looking for some info...
I need to know what is the difference between a 3-25 Early VS a 3-25 late?

Also looking for an IPL for a 10-10 and the 3-25 if there is one

picked them both up early this year in a lot of 8 saws for $100...3-25 runs, needs some tweaking...10-10 runs like a raped ape..great running saw

Thanks in advance

Jeff

bookmark this link, it is all you need to know.

McCulloch Page

 

[ozflea]

bookmark this link, it is all you need to know.

McCulloch Page

Looks as if most of that info came straight from my Mac CD pity really as it took bloody ages to scan and apply to a CD which i have sold for many a year

Thanks ol mate

now i know why my CD's stopped selling bloody pirates ...................... and they give my work away for free
McBob.

 

[homelitejim]

Looks as if most of that info came straight from my Mac CD pity really as it took bloody ages to scan and apply to a CD which i have sold for many a year

Thanks ol mate

now i know why my CD's stopped selling bloody pirates ...................... and they give my work away for free

McBob.

Well let me be the first to say Thank You! It is not often I get to thank someone who actually did the work so that all may have access to this free information, just hope you recouped all your investment before this went viral.

 

[ozflea]

Well let me be the first to say Thank You! It is not often I get to thank someone who actually did the work so that all may have access to this free information, just hope you recouped all your investment before this went viral.

What was free about it nothing till some clown loaded it up on his web site as a freebie i worked hard and spent heaps collecting all this paying as i went i got no freebies.

Thanks again

Bob and guess what i'm not to happy .

 

[OldDeadWood]

IPLs

McBob

At least he's not selling the IPLs and making a profit directly from you work.:msp_mad:

That would realy hurt.:mad2:

I purchased one of your CDs a while back and I'd like to say thanks also.:msp_thumbup:

ODW

 

[heimannm]

McCulloch BP399T

No. of cylinders 2
Bore 2.750"
Stroke 2.048"
Displacement 24.33 In³ (399 cc)
Speed range 2000-7000 RPM
Length 16.5"
Width 11.25"
Height 14.30"
Spark Plug Champion L78 or eq
Spark plug gap 0.025"
Timing 26° BTC

According to the article in Popular Science magazine it was rated at 30 HP.

I will have to get a weight next weekend when I am home again.

Mark

 

[a. palmer jr.]

What was free about it nothing till some clown loaded it up on his web site as a freebie i worked hard and spent heaps collecting all this paying as i went i got no freebies.

Thanks again

Bob and guess what i'm not to happy .

Was there not some way to get your work copywritten or otherwise protected like some CDs are?

 

[heimannm]

ODW - the pistons are pretty close to the same weight, the smaller one is almost solid. There is a definite supercharging effect from the balance piston. According to one comment on line, the emissions from the BP engines were higher than other 2 strokes, and fuel consumption was significantly greater as well. I can't say as I don't often run a full tank through my BP-1 at any one time.

The official explanation for removing the BP-1 from the market was concerns about overspeeding if the governer failed causing the engine to disintegrate at high speed. Other sources also discuss the heat issues, as well as the complexity of the engine and the concern about qualified mechanics to work on them.

Mark

 

[thomas1]

ODW - the pistons are pretty close to the same weight, the smaller one is almost solid. There is a definite supercharging effect from the balance piston. According to one comment on line, the emissions from the BP engines were higher than other 2 strokes, and fuel consumption was significantly greater as well. I can't say as I don't often run a full tank through my BP-1 at any one time.

The official explanation for removing the BP-1 from the market was concerns about overspeeding if the governer failed causing the engine to disintegrate at high speed. Other sources also discuss the heat issues, as well as the complexity of the engine and the concern about qualified mechanics to work on them.

Mark

Mark, you need to update your sig line.

 

[Eccentric]

This engine is in the McCulloch 740 sent to me by an AS member a while ago. Block # is 58486A. I've only found that # in one McCulloch publication (one of the earlier Pistons/Rings/Cylinders lists). Listed as W1 Welder engine. 103cc, and shares one piston # with one of the bevel drive 'two man' saws. Notice that it has an oval, unbridged exhaust port, thin rings, an unmachined DSP valve boss, and much larger cylinder head fins than a 'normal' super series one man saw engine. The fins aren't rounded either. Whoever put this engine in the 740 bent some of the fins over so they'd fit under the cylinder shroud. There is a blind hole where the third muffler bolt would go. Bolt spacing for the muffler matches 'standard' McCulloch saw mufflers. I haven't put the saw in wood yet, but it has tons of compression and 'feels' very snappy when revved.

Here's my very dirty 790 engine for reference. This block is marked "1-76/1-76" with strikes through those numbers, and "790" on the unmachined 'lubrimac' boss. I measured the bore through the exhaust port and it matches the 103cc saws (rather than the 99c saws such as the 1-76 and 1-86). Notice the smaller, more rounded head fins, the threaded boss for the third muffler bolt, the lack of a DSP valve boss, and the 'normal' three port exhaust.

Got a vid of that saw running eccentric?

Not yet. Probably will after the GTG in a few weeks.

[video]http://s171.photobucket.com/albums/u318/Eccentric_photo/McCulloch%20Chainsaws/?action=view&current=photobucket-3218-1350782738075.mp4[/video]

Here's a short cellphone video I shot of the 740W1 (LOL) on Saturday afternoon after I rebuilt the carb and took care of a few other minor issues. No cutting video yet. Cut and ripped a couple pieces of oak with it. It's STRONG, but I need to rehab the chain. Those RH start Macs don't clear noodles from the clutch cover/starter very well either....