Reasons For Excessive Carbon Buildup?

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The oil ratio has nothing to due with carbon build up as long as the saw is tuned to run at that ratio i run 32:1 with high end synthetic oil and have zero carbon build up.


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Thanks for your input. I will ponder this mix more, after I get a true compression test tomorrow.
 
What? Excessive carbon build up? It's in all the dang papers! Some people say it ain't so, no way, it is so! Not sealing cracks around doors and windows, big huge mambo mommas driving around gangs of fatkids in SUVs, burning huge electric signs at night so the dang space alines know to drink coke and wear nike shoes! Fossil fuels man, too much carbon!

And you know what happens next, planet heats up, turns back into the hot swamp scene action, a few drunk deranged sciencetwits get to playing around with recombinant DNA and gene splicing, and, before you know it, freeking dinosaurs stomping around!

Boom! Boom! Boom! ROARRRRRAARRRRR!

Then they look down, yum! Roly poly pre-stuffed slow ground monkies! Chomp! Burp! Taste jiss lak bacon! Dinosaurs love bacon!

See, excessive carbon build up, just say no, or THIS happens!


That is a really big lizard ;-)
 
That is a really big lizard ;-)

Boom! Boom! Boom!

eek! too much carbon!



Idea! Them big hungry guys eat like ground monkies, army tanks, city buses, etc, but...they don't eat carrots! You never see them eating carrots! Just get you a carrot costume, one of those stomping dudes comes by real hungry, just stand still, they'll ignore you!

Good luck man!
 
Wouldn't running a thinner fuel mix of 40:1 or so, also be a hotter fuel mix, as well as being a cleaner mix, and burn most of that carbon up and blow it on out of the muffler at operating speed?

The more oil in the mix, the more oil gets cooked off through the port; very little of it gets burnt. Simple enough. That cooked-off oil shows up mainly as POM- polycyclic organic matter, a serious carcinogen and transporter of such. Besides deposits, depending on other factors.

Once the mix concentration is settled on, then you adjust the carb. Then, as mentioned earlier, you have to RUN it. Meaning extended full power runs, doing work. Babying it is abuse. Once it gets proper use on a regular basis, it'll be spitting out deposits- be sure to keep the spark-arrester.
 
I'd like for you guys to look at these pictures and give me your opinions if you would. After I gave this saw a good cleaning, I decided to pull the muffler off, and see what the cylinder exhaust port and front side of the piston looked like. There is quite a bit of carbon build up around the port, but there are not any scratches, gouges, or aluminum dust or flakes on the skirt, or top of the piston, or the ring. I have not done a comp test on this motor myself, but I was told by the guy that I bought it from, that he did in fact do one recently, and it held between 110-115 psi. Ain't that kinda low? And here again, check out the spark plug (Autolite 2976) I believe? It's a little wet around the threads. And, there was not a gasket between the muffler, and the exhaust port.

What would cause the excess carbon build up around the port? (no gasket)? (blow By)? (stuck ring)? Or, just running the carburetor fuel mix way too to rich? or all of the above? He said that he had always ran a 32:1 gas/oil ratio, if that might have something to do with it. If this carbon build up isn't anything to be concerned with, as far as the condition of the top end is concerned, is there a way to clean it up to a smoother port surface? or would there be too great of a chance of some of it getting into the combustion chamber, and causing even bigger problems?
Tell me what you think.
SlangView attachment 348940
It really doesn't look bad at all. How does it run? If it runs well I wouldn't worry about the compression read you were told, as if it was taken with the wrong type of gauge it will be low.
 
I run Belray H1R @ 32:1 in all my two-stroke power equipment. No buildup of any kind, ever.
Might be due to the fact that synthetics are cleaner burning and are formulated to resist deposits and saw is in tune, that'd be my guess.
 
The oil ratio has nothing to due with carbon build up as long as the saw is tuned to run at that ratio i run 32:1 with high end synthetic oil and have zero carbon build up.


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Please listen to this poster, this is right.
PS, your saw is not that carboned fyi.
I run 20:1 and do not have carbon at all.
(If your are getting lots of carbon...)
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It's you jetting, (too lean). And the oil QUALITY (poor base oil), and FUEL quality (USA pump gas is dirty burning).

If you can afford it, use the canned premixes available everywhere now, or buy bulk racing gas non oxygenated -110 octane- and add your own oil. All the factory oils are great oils. I think the Red Armor is especially good. Stihl and Red Armor are ashless chemistry.

You need to adjust your tuning to your fuel mix and the day's weather.
 
I would avoid high octane fuels in a saw engine.

Unless you enjoy wasting your money to have less power.
 
The oil ratio has nothing to due with carbon build up as long as the saw is tuned to run at that ratio i run 32:1 with high end synthetic oil and have zero carbon build up.


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+1, I was getting heavier carbon buildup @ 50:1 than I am now @ 32:1.
Luckily it still didn't cause a problem, but was a PITA for Randy to remove when he went to port them.
Never did quite figure out 100% what caused it, as the saws with this condition ran great and seemed well tuned.
Did switch oils based on this, and Randy's recommendation. No problem's so far
 
+1, I was getting heavier carbon buildup @ 50:1 than I am now @ 32:1.
Luckily it still didn't cause a problem, but was a PITA for Randy to remove when he went to port them.
Never did quite figure out 100% what caused it, as the saws with this condition ran great and seemed well tuned.
Did switch oils based on this, and Randy's recommendation. No problem's so far

And how many saws do you have that I ported? :)
 
It's a Lucky #.
I'd be willing to bet at least half of those are the same models too. We have similar tastes, As I also like Pie....
 
Well, I went into town today and the only place that had a comp gauge was an automotive repair shop. The gauge that they had for use, was an automotive V-8 engine type that uses a quick disconnect coupler half way up the hose, between the spark plug fitting and the gauge itself. I did manage to get a reading on it though, exactly 100 psi. I don't know how accurate this reading is, considering this dude's gauge assembly had a 24" two piece quick disconnect hose. Plus, he was a certified ******* to deal with as well. But, this at least gives me an idea of what I'm dealing with. There's not another place that I know of, within 75 miles of my home that can do an intelligent compression test on this engine. I ...WILL ... BUY ... myself a small engine compression tester, as soon as things settle down here, and I can get a few spare bucks.

I have heard, and seen this saw run, but it was so darned cankered up with gunk, and sawdust, the first thing that I did when I got it home was to take it apart and clean the darned thing. And that, lead me to my original question to you all about the carbon, and the compression. I just wanted to get some good experienced opinions, before I put it to work. I just didn't want to start using it right off the bat, and blow the darned thing up. I've never blown one up......knock on wood (no pun intended). What do you think about the compression reading this morning at 100psi considering the automotive gauge that I had to use?

Thanks guys
Slang
 

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