trying to get the feel of carb adjustment help

[1stmale]

Ok

I have read every thread and many other articles on carb adjustment.

I have some questions.

I am setting the L screw half way between extreem rich and extreem lean there seams to be a wide range where it seams to run well. Does the L screw have a wide range for where it can be set and still run well? Is there any damage that can be done to the saw by a misadjusted L screw?

I am setting the idle speed with a tach.

I am setting the H screw with a tach to the max RPM.

After I put a load on the saw i.e. cut wood and rev it up to max RPM to listen to it it sounds like it revs higher than the max setting for a short time then if I let it idle for a few seconds the max RPM sound returns to to normal. In both cases it "4-cycles" I cut several logs then rechecked the max RPM with my tach and it was fine.

Is this due to extreem heat durring load causing a temporary leaner condidtion and then when it idles it cools off? Or is it just a hearing perception like an optical illusion?

Am I just worying to much and to much of a perfectionist?

Thanks

Adam

 

[1stmale]

Please help I am just trying to feel comfortable with working on my saw myself. I work on everything else I own why not these.

 

[Cut4fun]

Here is where i learned. You will get the hang of it soon enough. I start at 1 turn out to get it started. Then by ear for me, no tach on hand. Plus I trust my ears. http://www.madsens1.com/sawtune.htm

 

[Four Paws]

Please help I am just trying to feel comfortable with working on my saw myself. I work on everything else I own why not these.

Dude...there was only 3 minutes between your posts...you have to give it time. Well, your first post leads me to believe you are adjusting a carb with limiter caps on - is this true? Have you modified your saw in any way yet (muffler mod, etc.)? If you have, it would be a good time to remove those limiter caps.

As far as adjusting your carb - it is not science. Using a tach is better than most of our ears...so you are getting some accurate adjustments. If you want your saw to run spot on, a tach is great! But, if you change bars in the field, packing a tach around is more of a nuisance. The fail-safe method of setting your carb is to make sure at WOT, out of the wood, the saw is 4-stroking. I adjust my saws by setting them until I hear an obvious burble (4-stroke) and then turn them in until it goes away (engine races) and then back them out about 1/8 turn...no melted pistons to date - knock on wood. All my carbs are fully adjustable and not limited.

 

[Lakeside53]

So long as your saw accelerates without stumbling, you will be o.k. with any reasonable any L setting. I set mine slight richer than the "center" (saw will start to idle slower), then turn up the LA screw to compensate. The LA is increased until the chain just starts to run, then backed off about a 1/4 turn (depends on the saw). If you can't stop your chain from running at a reasonable idle speed, fix the clutch.


H is more complex... If it's really is 4-cycling, your carb H screw is CLOSE to standard settings (like 1 turn out), and your max rpm isn't exceeded, you'll probably be o.k. What is your max rpm on the tach when you think it's too high?

You might want to do yourself a favor though and set the saw richer than max... just in case you have other problems like leaky seals, an imperfect impulse hose, crappy fuel filter, etc.. In any case, it will cut just as fast.


BTW, what saw are we talking about?

 

[1stmale]

Dude...there was only 3 minutes between your posts...you have to give it time. Well, your first post leads me to believe you are adjusting a carb with limiter caps on - is this true? Have you modified your saw in any way yet (muffler mod, etc.)? If you have, it would be a good time to remove those limiter caps.

Sorry I was not trying to be pushy. I just wanted to make a point. Sorry that it came across wrong.

The limiter caps are off. No muffler mod.

I do not have other bars so I do not change them in the field. Besides most of my cuting is done at home by my shop.

So long as your saw accelerates without stumbling, you will be o.k. with any reasonable any L setting. I set mine slight richer than the "center" (saw will start to idle slower), then turn up the LA screw to compensate. The LA is increased until the chain just starts to run, then backed off about a 1/4 turn (depends on the saw). If you can't stop your chain from running at a reasonable idle speed, fix the clutch.

I am comforted knowing this. I to set it slightly rich.

So I know this is correct.

H is more complex... If it's really is 4-cycling, your carb H screw is CLOSE to standard settings (like 1 turn out), and your max rpm isn't exceeded, you'll probably be o.k. What is your max rpm on the tach when you think it's too high?

I set the carb to ~12.4K the max is 12.5. When I recheck it it is repeatable.

I am going by sound when I think the RPM is to high not tach. Again it only sounds high just after finishing a cut. Shortly after when it has idled for a short time it returnd to normal. This might be a perception thing I this is why I am asking if it it normal or not. If not, I am probably percieving a high RPM when it is not.

The saw in question is the 345.