Late 80's McCulloch 2.0 CID Eager Beaver

[Multifaceted]

I've searched these forums and elsewhere in the past few months for info on this old saw, and thus far it's been helpful. I'm trying to get this little old saw running reliably again. I have no other use for it, but it was my late father's, who neglected it for the past twenty or so years, probably longer. I want to get it running again, reliably, just to have my old man's saw working, no other reason. When it was being used, it probably only saw maybe 2-3 hours of runtime, so the saw is really only old and has been sitting. The piston head has some fouling, but otherwise seems in good order.

When I found it, the bar was bent and rusted, as was the chain. I got it home, replaced the spark plug, air filter and filled it with fresh gas (50:1). After a few pulls with starting fluid, she fired up and stayed running. Got the carb tuned enough to actually do some work, but it was still running erratic, and was leaking fuel. I ended up disassembling it to replace the fuel line, only to get frustrated with the carb adjustments again and ordered a car rebuilt kit. I then disassembled it again, replaced all of the diaphragms and gaskets, metering lever/needle/spring, and gave the carb a thorough cleaning with carb cleaner and compressed air. In hindsight, I probably should have soaked the metal parts in acetone overnight before reassembling...

After doing all of that, the old girl starts, but stalls out in idle. I've tried resetting and adjusting the hi/lo needles and idle screws to no avail, she starts, runs with the throttle open for a bit, but then stalls out. Sounds throaty, somewhat four stroking, so nothing appears (in my limited experience with 2 stroke engines) to be off. I'm pretty sure I reassembled the carb correctly, but I might need to adjust the height of the metering lever, and I'm thinking of completely overhauling the carb and soaking all of the metal parts in acetone, and the plastic parts in soapy water. The manuals I have found state that it ran McCullouch special 40:1 fuel mixture, but I've been running 50:1 as my other old 2 stroke engines run that fuel ratio well, I just have to regularly clean the spark plugs from fouling up. Should I be running a different fuel/oil ratio?

Does anyone else have any more recommendations on these little old saws? If you have one, then you know how much of a PITA it is to take it all apart, reassemble it just to find out something is still off... Very frustrating saw to work on, but it was my dad's, so I want to put it back in use again.

Here's pics:

 

[alexcagle]

Nice Beaver......lol
I have the cutoff saw version, but it's an ugly, nasty and somewhat "un-Eager beaver".
*
Check your compression.
Check your impulse connection, and that it's clear.
Check your tank vent that it isn't blocked, causing a vacuum buldup, and subsequently leaning the saw out.
Recheck the internal carb screen for debris blockage. It doesn't take much to plug them up sometimes.
If you reused the fuel hose it may be rotting internally, and shedding rubber.

 

[Old2stroke]

Can you be a bit more specific on the problem? Does it run well at full power when cutting (high speed adjust.)? Does it drop to idle properly right after a cut? Does it idle well for awhile and then slow down and die? Does it idle well but bog down and die when the throttle is snapped open? Is the problem the same when the engine is hot or cold. That saw looks like a close cousin to the MiniMac 110 that a lot of us love and most people hate.

 

[Multifaceted]

Nice Beaver......lol
I have the cutoff saw version, but it's an ugly, nasty and somewhat "un-Eager beaver".
*
Check your compression.
Check your impulse connection, and that it's clear.
Check your tank vent that it isn't blocked, causing a vacuum buldup, and subsequently leaning the saw out.
Recheck the internal carb screen for debris blockage. It doesn't take much to plug them up sometimes.
If you reused the fuel hose it may be rotting internally, and shedding rubber.

Thanks for the input, I'll look into all of that. I'll have to see if I can borrow a compression gauge. As to the fuel line, it's G2G - I replaced with with a new length of Tygon fuel line, the existing one was cracked and deteriorated. I'm going to proceed with overhauling the entire carburetor and soaking it overnight in acetone, then blow out again low pressure compressed air. There was some considerable varnish around the welch plug, that should NOT need to be sealed or anything, correct?

Also, there isn't a breather on the fuel tank that I can tell, or rather I'm not seeing it. There is one female inlet that has a fine mesh screen on the outside, then a sponge or felt type filter on the inside that I cannot seem to remove or find a replacement. The fuel line connects to the tank inlet via a 1/4" male connector with an o-ring to seal. The fuel line connects the male connector to the barbed fuel inlet to carburetor. On the carb diaphragm plate there is a small 1/4" opening with a screen over it retained by an e-clip, is that the breather perhaps?

Can you be a bit more specific on the problem? Does it run well at full power when cutting (high speed adjust.)? Does it drop to idle properly right after a cut? Does it idle well for awhile and then slow down and die? Does it idle well but bog down and die when the throttle is snapped open? Is the problem the same when the engine is hot or cold. That saw looks like a close cousin to the MiniMac 110 that a lot of us love and most people hate.

Sorry for not being very descriptive, was very tired when I got home and posted that, thought I had it all covered. Anyway, before replacing the parts in the carb (with new fuel line) the saw was running fairly well without any load, staying in idle and accelerating with the throttle open. When I would tune it in wood, it was a little finicky. When I would adjust the hi speed jets it would hesitate in the cut like it wasn't getting enough fuel, so I would adjust to rich it up, but that would start smoking and then the throttle response would be jerky and hesitant. As the saw warmed up it just became erratic and prior adjustments behaved differently. The same adjustment that was cutting now bogs down during the cut and then it would slow down and stall in idle. That's where I decided that a 25+ year old carb needed to be cleaned and parts replaced.

Fast forward to replacing the parts from the rebuild kit. Saw starts, runs with throttle open, but upon taking the throttle lock off to let idle is quickly slows down then stalls. After a few tries it didn't seem to get enough power for the clutch to engage the sprocket drum and would quickly stall in full throttle and in idle, so I took the bar and chain off to try and adjust the fuel mixture and idle speeds. When it starts, it will not stay in idle and will slow down and stall. I've tried to again rich up the lo jet and idle screw to no avail. In full throttle, it sound slike it's drafting enough fuel. I can keep it going long enough to adjust the hi jet and it's right about where I want it; however, still - when I let off of the throttle, it slows and stalls quickly.

I've reset the screws by seating both, then backing out one full turn as per the 110 manual I found, which I believe to be a similar if not the same saw. This has a yellow air cover; whereas the 110s seem to be black. Not sure if that matters. Even after resetting the screws and trying to adjust from there, the same problems persist. I notice as the saw warms up, the acceleration is hesitant and feels like it's not getting enough fuel, so I'll rich it up a 1/16" turn at a time until it runs better, then stalls at idle. When I start it again, the open throttle then sounds too rich. If the carb was not assembled correctly, it wouldn't run at all, right?

 

[alexcagle]

You may benefit from the "beg for manuals" thread on here.
The idle needs set first, then the high speed.
The female inlet with screen inlet should be the vent. It allows air in, but no fuel to leak out.

 

[Multifaceted]

You may benefit from the "beg for manuals" thread on here.
The idle needs set first, then the high speed.
The female inlet with screen inlet should be the vent. It allows air in, but no fuel to leak out.

I have a manual that I found online for the 110 which I believe to be a slightly newer version of the one I have. I have tried various combinations of adjusting the idle using the lo and idle speed screws, at one point I've even gone as far as opening up the look jet a full turn from the basic setting.

I hope it's just some errant build up that got moved from one spot to another when I was spraying it out with carb cleaner. I'm just trying to gather any other possible things to correct so I don't have to keep disassembling and reassembling. You have to take the whole thing apart just to access the carburetor which is mounted to magnetic coil. I can see why so many get frustrated with these little saws, but this was my dad's, so...

 

[Trx250r180]

I have a manual that I found online for the 110 which I believe to be a slightly newer version of the one I have. I have tried various combinations of adjusting the idle using the lo and idle speed screws, at one point I've even gone as far as opening up the look jet a full turn from the basic setting.

I hope it's just some errant build up that got moved from one spot to another when I was spraying it out with carb cleaner. I'm just trying to gather any other possible things to correct so I don't have to keep disassembling and reassembling. You have to take the whole thing apart just to access the carburetor which is mounted to magnetic coil. I can see why so many get frustrated with these little saws, but this was my dad's, so...

I will normally give a carb 2 times with a cleaning ,if that does not work i replace it ,sometimes the crud gets in a little hols and just wont flow fuel right,did you take the h and l screws all the way out and spray carb cleaner in them and get a good flow out the other end when carb was apart ?

 

[a. palmer jr.]

Not sure I would use acetone to clean carb with, at least I've never tried it. Just regular carb cleaner should do it..

 

[dougand3]

Your saw should be a 600xxx model #. Look for a plate. Search web for "McCulloch 600xxx". Normally, can get the exact IPL.
Eg: An Eager Beaver 2.1ci is 6000157.

 

[Multifaceted]

I will normally give a carb 2 times with a cleaning ,if that does not work i replace it ,sometimes the crud gets in a little hols and just wont flow fuel right,did you take the h and l screws all the way out and spray carb cleaner in them and get a good flow out the other end when carb was apart ?

That's my line of thinking as of late, and no, I didn't remove the hi/lo jet screws out when I cleaned it. I'm kicking myself for not doing that now, I suppose at the time I figured that it was running reliably, albeit erratically, so I didn't think to get to those. They're probably gummed up with whatever got loosened up from the carb cleaner. I'll plan on doing that when I take it apart again. I hope this solves the issue because Walbro doesn't manufacture the carb for this saw anymore, nor does any ChiCom knockoff that I know of either...

Not sure I would use acetone to clean carb with, at least I've never tried it. Just regular carb cleaner should do it..

Neither have I, but it also dissolves resin and build up, I think some carb cleaners list it as an active ingredient. I do have aerosol carb cleaner, just figured the acetone would be less wasteful to soak in and save the carb cleaner for spraying out the ports and jets. The acetone would only be used on the metal parts. Either way, I think it would benefit from a good soak fully immersed.

Your saw should be a 600xxx model #. Look for a plate. Search web for "McCulloch 600xxx". Normally, can get the exact IPL.
Eg: An Eager Beaver 2.1ci is 6000157.

I'll look for that, thank you. Other than using that to source parts and a manual, what else would the IPL help me with finding?

 

[Old2stroke]

If you are going to do a proper job of cleaning old carbs that have been sitting around for a long time, as well as removing the mix screws, you have to remove the welch plugs and see what is lurking under them. Usually a large plug covers a cavity where there are 2 or 3 small holes that supply fuel to the idle port and transfer ports, these have to be clean. A small plug covers the cavity where the main jet gets it's fuel and there could be a small screen there that has to be clean. Also the main jet may have a nozzle check valve that can be a real problem as it has a small rubbery puck that can be damaged by alcohol in the fuel. Sometimes the check valve can be tested by holding a small tube against the valve and doing a suck and blow test on it to see if it seals when you suck and is free when you blow. When putting the carb back together, make sure the gasket for the main metering diaphragm is on the carb side (wet side) and the gasket for the fuel pump diaphragm is on the cover side. The setting of the inlet valve control lever is critical and is usually set flush with the surrounding carb metal but could vary depending on what carb you have.
Do you have a good spark? Do you space the coil tight against the flywheel with a business card as a spacer?
Don't give up, with a little more practice you can get these little beggars apart in 15 minutes.

 

[Multifaceted]

Thanks for all of the pointers and recommendations, fellas. I'll be getting back to the work bench again on this here pretty soon.

@Old2stroke - excellent, these are the types of things I was looking to get, thank you kindly! I'll be wary of the check valve, though I don't think on this one the alcohol would have played a role, I think the last time it had fuel in it was years before refineries started adding ethanol to gasoline/petrol.

As to the spark, it is good, brand new plug and was gapped to 0.025" as per the 110 manual. The coil I spaced with a piece of plastic that was about the same thickness, but it was moving around a bit so I'll look for that again when I reassemble. I'm also thinking that the lever isn't spaced correctly either, this one has a little circular plastic tab with a small pin in the center that sits in a small hole in the metering lever which is actuated by the metering diaphragm. First I've seen one like that, but because of that part I don't think the lever is seated correctly.

All in all, I've generated a nice little checklist and pointers for when I give this another go. I'm feeling pretty confident now that I can get the old girl going again. As to the disassembly, you're right, it's not all that bad and it gets faster each time. The only part I hate is re-attaching he throttle linkage to the plastic throttle trigger. I wish I had a pair of 3-prong pliers just for that task. Again, thanks to all who have chimed in here - cheers!

 

[a. palmer jr.]

Although Walbro may not be making that carb anymore they still make carburetors with that prefix (like WA or WT) so it's possible to keep some levers and shafts from your carb and exchange the ones from each carb to conform to your saws needs. Or, if that's not an option you can still find plenty of carbs at old small engine shops because lots of those saws were scrapped out. I had a chance to buy one of those saws last summer for $1 and I declined.

 

[Multifaceted]

Although Walbro may not be making that carb anymore they still make carburetors with that prefix (like WA or WT) so it's possible to keep some levers and shafts from your carb and exchange the ones from each carb to conform to your saws needs. Or, if that's not an option you can still find plenty of carbs at old small engine shops because lots of those saws were scrapped out. I had a chance to buy one of those saws last summer for $1 and I declined.

You can still buy rebuild kits for the carb, so that's good. I do keep a lot of old or unused parts from other equipment for just that reason, so that's good to know. Yeah, these saws have a love hate relationship. There's no middle ground, it seems either folks love them, or they hate them. I'm just trying to get it running because it belonged to my late father.

 

[Old2stroke]

If your control lever has a fork in the end (never seen one with a hole), that button on the metering diaphragm has to be hooked into the fork when the carb is being assembled. One trick that helps when putting it back together, is to hook an elastic band to the end of the throttle wire link and hook the other end of the band to something on the front of the saw, keeps the damn thing from disappearing.

 

[Multifaceted]

If your control lever has a fork in the end (never seen one with a hole), that button on the metering diaphragm has to be hooked into the fork when the carb is being assembled. One trick that helps when putting it back together, is to hook an elastic band to the end of the throttle wire link and hook the other end of the band to something on the front of the saw, keeps the damn thing from disappearing.

If I remember correctly, one side of the lever has a fork for the metering needle valve, and the other a little hole for the pin on the plastic tab that goes under the diaphragm (unless I'm mistaken, only taken that carb apart once so far). I probably could have done a better job at paying attention when I was taking it apart before reassembling with the new parts, but I think I've got a good idea now. Was hoping to get to it tonight, but ended up getting home late. I like the idea of the rubber band for the throttle link. Got any tricks on snapping that bad boy back in place of the throttle trigger? I always feel like if I press to hard I'm going to break the plastic, then I'll be S.O.L.

 

[Old2stroke]

Yeah, you have to be careful with the plastic piece, I'm usually able to install it by squeezing it in with needle nose pliers. On occasion I have had to use a pair of long needle nose pliers.

 

[Multifaceted]

Many, thanks. Took apart the old girl this evening and put the main metal-only parts into a mason jar full of acetone. After a few minutes I started seeing some gunk settle on the bottom. Will put back together this weekend and get 'er fired up and running well enough, hopefully, to tune in some wood and maybe do some sawing. Thanks again for the help!

 

[a. palmer jr.]

Most unusual fuel line and filter. I think mine was crushed somehow and I had to take mine apart several times..I no longer have it.

 

[John Lyngdal]

I wish my work bench was so organized. Best of luck getting the saw to run as it should.
Had a top handle Stihl 015 that I couldn't get to run properly to save my life. Rebuilt the carb and still no joy.
Came across another 015 that had other issues and swapped the cab on to my saw and it ran nicely.
Have no idea what the real issue was with the original carb, but the saw has a new home now and the owner is happy.