034 Muffler question

[davefr]

If it bogs in the cut then it sounds like it needs to be richened up vs. leaned down.

Get it as "close to smooth while still in the rough" and make sure it doesn't bog in the cut.

 

[Lakeside53]

As I mentioned in a previous post, I open up the muffler output on my 034 from 0.625" to around 0.750". Today I had a chance to go out and give the saw a try. First thing I noticed was that the saw bogged when I throttled, the solution was to open (richen) the low speed adjuster slightly. After I got the saw accelerating nicely, I opened the high speed adjustment just a touch. (I read in previous posts that you need to run a little richer after opening the muffler up). I proceeded to make a few cuts in a large piece of poplar and the saw was really preforming nicely. After the saw was warmed up, I used my hand held tachometer to check the no load RPM's. The saw was running lean so I adjusted the high speed screw to max out at 13,000 as indicated in the saw manual. After doing this I tried to make a few more cuts and the saw did not like the setting and bogged in the cut. That leads me to my question. Can I readjust the carb forgetting about the no load speed and adjust for max performance? If I do this will I be risking running the saw too lean? I would appreciate some feedback here. I did search the forum on carb adjustments and read up a bit but I figured someone might be able to elaborate here.

Tom

No, you can't ignore the WOT setting, and it's a max... don't exceed it unless you're a racer and only care about 30 seconds of cutting... You can of course set it lower. Try the "turn H screw in to a clean sound and then back to a burble... Then check with a tach.

Did the saw do this before your muffler mod?

If you have a standard muffler front around, put it back on and test the saw again - there is a chance you've opened the muffler up too much. Also, just for interest, what is the saws compression?

 

[v8titan]

No, you can't ignore the WOT setting, and it's a max... don't exceed it unless you're a racer and only care about 30 seconds of cutting... You can of course set it lower. Try the "turn H screw in to a clean sound and then back to a burble... Then check with a tach.

Did the saw do this before your muffler mod?

If you have a standard muffler front around, put it back on and test the saw again - there is a chance you've opened the muffler up too much. Also, just for interest, what is the saws compression?

Ok. I checked the compression and it's running 155 psi. So, my guess is that's not a problem. The saw ran fine before the muffler mod. But, it ran extra strong after the mod when I leaned out the mixture a bit. It only ran a little poorly when I set the no load speed to 13K with the tach and then tried a cut. Maybe I have the setting a little too rich. I will try your approach of adjustment by ear and check the no load speed. I will give that a try tomorrow.

 

[davefr]

Generally with a muffler mod you richen up H vs. lean it.

And if you stall out in the cut you're too lean.

How many turns out is the H and L currently set at?

I'd start from the factory settings of 1 turn out and do it all over again.

I believe my modded 034 is at about 1-1/8 out on the H and about 7/8 out on the L.

 

[Gravely Grinch]

Mine is set @ 1 1/4 H and 1 L with a modded muff.

 

[v8titan]

Generally with a muffler mod you richen up H vs. lean it.

And if you stall out in the cut you're too lean.

How many turns out is the H and L currently set at?

I'd start from the factory settings of 1 turn out and do it all over again.

I believe my modded 034 is at about 1-1/8 out on the H and about 7/8 out on the L.

I had a chance to readjust my saw and it runs fine now. I adjusted it by ear first, made a few cuts, then check it with the tach. I'm getting the 13K no load RPM like the book calls out. My H screw is just a hair past 1 turn out and the L screw is right at 1. I want to say that the mod helped performance a little bit. Still contemplating doing the 036 upgrade.