McCulloch Chain Saws

[Brian Thacker]

It could be too much fuel and wet flowing the plug. The carb could be way too rich and eth you squirting fuel down the intake is causing it to wet flow the plug. Have you checked the plug after you tried to start it and see if it is wet? If it's wet, then it won't fire, it is shorted out. Try and not put fuel down the intake but put your shoe into the handle and hold the throttle wide open and try start it. No choke.

Brian

 

[mogulmasher]

Yes I have checked the plug several times. It is always wet, but I wouldn't say soaked. Looks more like misted with oil instead of wet with fuel. I have lots of experience with flooded snowmobile engines, plugs look soaking wet when pulled. These aren't quite that wet.

Not sure I have a lot of fuel reaching the carb at this point. Carb will need to be cleaned, I just wanna fire it off with mix through it to figure out if it'll even run. Anyways, it does seem as though the primer is at least slightly working. I also did find low screw out 1.5 turns. I cranked it in to 1 turn out, gave the primer a few squirts, tied throttle wfo, and gave her some tugs. Still nothing.

Pulled plug again, moist, but not soaked.

 

[andrewsc]

Let my 10-10 sit most of today so fuel could evaporate. She actually turned over a couple of times on her own.
Tomorrow I'll go through the carb again and replace metering needle and clean it one more time.

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[sawfun]

Have you put a squirt of mix in the cylinder, then installed a clean dry plug and tried it? Is there any wet, be it oil or mix, out of the muffler? Though likely not it at this point, were the points clean, dry (some electric contact cleaners have a lubricant that can cause an issue) and set between .015 and .018? Is the flywheel and or magnet placement correct? Are the coil and plug wires clean and tight? Maybe a wire has an unseen break in it. Just because you see spark, even good spark, doesn't mean it isn't breaking down under pressure. I've had solid stainless plug wires go bad.

 

[andrewsc]

Have you put a squirt of mix in the cylinder, then installed a clean dry plug and tried it? Is there any wet, be it oil or mix, out of the muffler? Though likely not it at this point, were the points clean, dry (some electric contact cleaners have a lubricant that can cause an issue) and set between .015 and .018? Is the flywheel and or magnet placement correct? Are the coil and plug wires clean and tight? Maybe a wire has an unseen break in it. Just because you see spark, even good spark, doesn't mean it isn't breaking down under pressure. I've had solid stainless plug wires go bad.

Oh yes lots of mix out the muffler. No points, electronic.

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[PogoInTheWoods]

Sounds like you're just floodin' the hell out of it.

 

[andrewsc]

Sounds like you're just floodin' the hell out of it.

And not sure why.

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[mogulmasher]

And not sure why.

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Did you get that needle to stop leaking?

 

[andrewsc]

Did you get that needle to stop leaking?

Going to work on it in a bit. Got to pick up a load of firewood I've got cut and split.

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[super44]

I had a tree worthy of bringing out a 125C for some run time. She ran a little rough but it has been 3 years since it was last run. It started on the 4th pull, as hard as these can be to pull over I was happy with that. The bar is 36 inches and the chain is new, it took "about" 10 minutes to cut this one up according to the video. It was fun to get this one in some wood again!

 

[Aaron Rybicki]

While we're on the topic of troubleshooting..

Here's a video of me firing the NOS 57cc Short Block from Bob Johnson! (Idle was tuned high)



Ran into some issues and am still having some. The chassis I used was from the severely scored Pro Mac 10-10 I had. When I slapped it all together - with the NOS block, it had the same problems as that saw. The scored saw never ran. It would only pop when pulling the starter cord. Occasionally, it would shoot a large red/purple flame out of the exhaust. Sometimes when it would pop, a big poof of white smoke shoot out of the carburetor.

The Bob Johnson saw did the same thing when I put it together. So I swapped in a similar carb. The end result was what you see in the video. It's been about a week since the video and I tried firing it again today. I pulled and pulled and pulled. Did not start. BUT it did shoot a large flame out of the muffler and at times would poof white smoke out of the carb like before. The old saw would actually leak fuel out of the muffler, even if I tuned it very lean.

I checked sparked before and it was blue but it wasn't real fat and prominent. I'm wondering if the spark isn't strong enough to handle the normal fuel consumption. Bad ignition module? If it's all the same components and the carburetor isn't the issue it leads me to believe it's ignition related.

 

[andrewsc]

Going to work on it in a bit. Got to pick up a load of firewood I've got cut and split.

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Today totally went South. Been at ER with my buddy. Just now headed home.

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[rwoods]

Hope you and your buddy are alright. Ron

 

[Todd Loosli]

Them best buddies take a lot of babysitting from time to time but you are always grateful that you have one. Take care

 

[Maintenance supervisor]

While we're on the topic of troubleshooting..

Here's a video of me firing the NOS 57cc Short Block from Bob Johnson! (Idle was tuned high)



Ran into some issues and am still having some. The chassis I used was from the severely scored Pro Mac 10-10 I had. When I slapped it all together - with the NOS block, it had the same problems as that saw. The scored saw never ran. It would only pop when pulling the starter cord. Occasionally, it would shoot a large red/purple flame out of the exhaust. Sometimes when it would pop, a big poof of white smoke shoot out of the carburetor.

The Bob Johnson saw did the same thing when I put it together. So I swapped in a similar carb. The end result was what you see in the video. It's been about a week since the video and I tried firing it again today. I pulled and pulled and pulled. Did not start. BUT it did shoot a large flame out of the muffler and at times would poof white smoke out of the carb like before. The old saw would actually leak fuel out of the muffler, even if I tuned it very lean.

I checked sparked before and it was blue but it wasn't real fat and prominent. I'm wondering if the spark isn't strong enough to handle the normal fuel consumption. Bad ignition module? If it's all the same components and the carburetor isn't the issue it leads me to believe it's ignition related.

If it's super easy to pull , I'd say your timing's advanced too much.

 

[PogoInTheWoods]

Timing is way off. Go over the ignition from the flywheel and key to the module and plug. Everything. Start by ensuring you actually have the correct flywheel and coil.

 

[andrewsc]

Success at last.http://cloud.tapatalk.com/s/5da09cdc0195b/20191011_100423.mp4

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[vinnywv]

Success at last.http://cloud.tapatalk.com/s/5da09cdc0195b/20191011_100423.mp4

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Great to see a success story, soooo what was it that you found or changed or replaced??

 

[andrewsc]

Great to see a success story, soooo what was it that you found or changed or replaced??

I changed the metering lever and needle

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[vinnywv]

Today was great for my firewood. I got all my logs drug to the house and started cutting and splitting. I only got 2 trees cut up, one of those split the other just cut. I used my pm850 with 28" bar and stihl full chisel 3/8 pitch chain (not skip). Once i got it tuned it cut like crazy! Its newer to me with a brand new piston and rings and newly replated cylinder. I was impressed with the speed and power. One tree was walnut the other shagbark hickory. It was easy going to say the least. Had em both cut up in no time at all. Next week ill be trying different saws all week....i think ill be grabbing the 850 often though...haha