Saw bogs when I try to give it more throttle

fluidpowerpro · January 15, 2022, 04:40:06 PM

I've got 2 saws that do this. One is a small Husky (14" bar, don't recall the model number) and the other is a Solo 654.
I can get them both to start, but when I try to give them more throttle, they bog/stall.
Any suggestions on what I should do. I assume carb adjustment?
On the Solo, I went through the carb and didnt find dirt or anything obvious.
Thanks,
Tom

HemlockKing · January 15, 2022, 04:45:36 PM

If they have spark arrestor screens in the muffler take them out might be clogged with soot gunk, take a blow torch to the mesh screen and burn it off

fluidpowerpro · January 15, 2022, 04:49:43 PM

Thank you. I will take a look.

TroyC · January 15, 2022, 05:09:51 PM

I've never had much luck cleaning those little 2 cycle carbs. I've replaced several for about 15.00, eBay. A small Stihl, a Husky, and a Honda pressure washer. All ran great.

fluidpowerpro · January 15, 2022, 05:11:49 PM

Probably not a bad idea. Ill explore that after I check the screen.

kenskip1 · January 18, 2022, 06:34:00 PM

How old is the mix? Was the mix stored in a vented can? If so it would be similar to drinking flat beer. Your saw might benefit from some fresh brew. Ken

deminin · January 18, 2022, 09:10:02 PM

If Both saws are doing the same, I would suspect the fuel. Empty the tanks, mix some fresh fuel, and try them again. Let them run at idle for a few minutes to use up any old fuel still left in the carb, then hit the throttle.

fluidpowerpro · January 18, 2022, 10:13:21 PM

Thanks for the suggestions. I know it's not old gas. In each case I was using new gas.

sawguy21 · January 18, 2022, 10:34:42 PM

Is the idle speed set just below where the sprocket starts to turn? Can you turn the idle mix screw to the left a bit to fatten up the mix? Just a tich, don't overdo it.

fluidpowerpro · January 18, 2022, 10:46:04 PM

Based on the suggestions, I think first I will check the spark arrestor screen.
Next I will try playing with carb settings. If I'm still not successful I'll look at replacing the carbs.

TroyC · January 19, 2022, 07:57:20 AM

A friend brought his Stihl over awhile back, same symptom. It was a clogged screen. Neither of us had actually seen that before, and when I told him the muffler was clogged he looked at me skeptically. Well, worse that skeptically. Sure enuf, cleaned screen and good as new. I had a discussion with him about oil and mixture. Problem solved!

fossil · January 19, 2022, 11:42:25 AM

While you're checking things, make sure the air filters are clean.

mike_belben · January 20, 2022, 11:48:01 AM

Dump the tanks and adjust carbs according to the madsens saw shop tuning procedure. If they wont tune the diaphragms are hardened up or they have base leaks or scored rings. Or maaaaybe tank vent issue.

John Mc · January 21, 2022, 10:47:54 PM

Quote from: sawguy21 on January 18, 2022, 10:34:42 PM
Is the idle speed set just below where the sprocket starts to turn? Can you turn the idle mix screw to the left a bit to fatten up the mix? Just a tich, don't overdo it.

Idle set too lean was the first thing that came to mind when I read the description of the problem. The other comments made here are also definite possible causes. A lean idle mixture can cause exactly the symptoms the OP described. Fortunately, is one of the quickest and easiest to check.

fluidpowerpro · March 05, 2022, 06:27:37 PM

Hi guys, finally had a chance to work on the Solo a little more today. Checked the screen on the exhaust. Not clogged. Removed muffler just to see what the exhaust port looked like. Seemed ok. Started saw again. Same issue. Noticed lots of raw gas in the exhaust while running. A few years back I bought an air filter choke assy and remembered I also got a carb with it so put on the other carb. Started easier but still the same bogging issue. Tried adjusting carb screws a little while running with no success. The saw then started backfiring. I could see flashes behind the carb. Maybe carb gasket or head gasket is bad? It has a Tillotson carb. The idle speed screw is obvious. There are 2 additional screws side by side. One is closer to the air cleaner side and the other on the same plane closer to the head. Can someone tell me which screw is which?

fluidpowerpro · March 05, 2022, 06:33:52 PM

Also, I don't have a compression gauge but if pulling it over is any indication, it feels like it has good compression.

sawguy21 · March 05, 2022, 07:17:23 PM

The one closest to the cylinder is the idle mixture screw, it should be turned out just far enough that the saw picks up cleanly without stumbling. The other is the high speed mix. There is no head gasket, it is one piece with the cylinder. The base gasket under the cylinder could be leaking but you would get hard starting and a very erratic idle.

GAB · March 05, 2022, 08:11:03 PM

I would suggest checking the fuel filter. From your description I think it is partially plugged.
GAB

fluidpowerpro · March 06, 2022, 07:00:31 PM

Thanks to everyone for your suggestions. Worked on it some more today. As suggested by MB, checked out info on Madsen's and used their instructions to adjust carb. The saw starts good. I was able to set the idle speed and it will idle smoothly for extended periods without stalling. Was able to set low speed screw per instructions also. When it comes to high speed, still no luck. No matter where I adjust it will never achieve high speed without bogging with backfiring. I also now notice a lot of bar oil coming oil around the clutch. Must be a bad shaft seal behind it. Question. Is a Solo 654 a saw worth putting a lot of effort into or is it "disposable" homeowner saw? I really don't need it. Just wanted to get it going for the sake of doing it. I have 3 other saws so I really don't need a 4th. I actually bought it cheap with the intent of mounting on a chainsaw powered winch, but it turned out to have the wrong kind of clutch.