Poulan strato tuning help

[Welderman85]

I don't have much if any tuning saws. I have been putting together a few plastic poulan I got for free. It has good 140 paint compression. I pulled and cleaned the carb . Replaced all the fuel lines and filter. It would start and run but idled high. I played with it a little but couldn't get it close. So I started over the screwed the needles in and started at 2 turns out. It still idled a little high and would die out after 5-10 secs of idling. I would rev up but burbles and did have much power.

 

[ammoaddict]

There are some good YouTube videos on how to tune a saw. Some were posted by members here. That's how I learned how to do it.

Sent from my Moto G (4) using Tapatalk

 

[redunshee]

Strato tuning is a *****. 2 to 2 1/2 turns out is not unusual

 

[Old2stroke]

The idle on these strato saws is adjusted and should run the same as any non-strato saw. You find the lean-best idle with the L screw and then back it out 1/4 turn to set it a little richer. Set the idle speed screw so that the engine is running just below clutch engagement. The high speed H setting gets a little trickier, start with it really rich, about 3 turns out so that you can hear an obvious burble in the cut then turn it in 1/4 turn and make another cut. Keep doing this until the burble in the cut goes away and it is just lean enough to run clean. Stop there, many of these saws get destroyed by running too lean. Do not attempt to set it with a tach at wide open throttle.

 

[Welderman85]

Would a muffler mod make it leaner or richer

 

[Old2stroke]

If you open up the muffler you have to retune it or it will be running too lean.

 

[Welderman85]

Ok I have a few questions. When should it 4 stroke
And what's a good sound clip to listen to to hear the correct sound. I had a few minutes today to play with the saw today. I pulled one of the bolt tubes out of the muffler to open it up a bit. I put both screws to the seats and backed them off 2 1/2 turns. It seems close I backed the low out a little more to get the idle down and it seems to run good. If you hold wide open for a sec it makes the 4 stroke noise I think. . I didn't have anything bigger to cut to test it on a good cut. Should it 4 stroke in a cut ? Also it surges a little sometimes at idle how do I fix that.

 

[Old2stroke]

Be careful removing those bolt tubes, without them the bolts will just distort the muffler and not adequately clamp the base of the muffler to the exhaust port. You have set the idle too rich and as the idle setting has nearly no effect on how it runs at high speed, it should be adjusted as described above and once adjusted properly the idle engine speed should be changed with throttle stop speed screw, NOT the L screw. When zeroing in on the right setting for the H screw, you have to have a decent size chunk of wood so that you can bury the bar in it and cut at full load for more that a few seconds. When making the first cut it should burbble (4-stroke) during the cut so that you will know it is too rich. Turn the H screw in 1/4 turn for the next cut and then do the same thing again for the next cuts. Eventually you will reach a point where the saw will run crisp and clean with higher rpm part way through the cut. You are almost there, keep turning it in until it runs this way right at the start of the cut. You may have to start with the H screw out 3 turns to make sure it is WAY too rich at the start.

 

[Welderman85]

Be careful removing those bolt tubes, without them the bolts will just distort the muffler and not adequately clamp the base of the muffler to the exhaust port. You have set the idle too rich and as the idle setting has nearly no effect on how it runs at high speed, it should be adjusted as described above and once adjusted properly the idle engine speed should be changed with throttle stop speed screw, NOT the L screw. When zeroing in on the right setting for the H screw, you have to have a decent size chunk of wood so that you can bury the bar in it and cut at full load for more that a few seconds. When making the first cut it should burbble (4-stroke) during the cut so that you will know it is too rich. Turn the H screw in 1/4 turn for the next cut and then do the same thing again for the next cuts. Eventually you will reach a point where the saw will run crisp and clean with higher rpm part way through the cut. You are almost there, keep turning it in until it runs this way right at the start of the cut. You may have to start with the H screw out 3 turns to make sure it is WAY too rich at the start.

Thank you for all your help. What's the best way to rest the idle screw? Butterfly closed or just cracked open. Inwas using the low to try and tune idle. And got everything out if wack lol. So I have to get the low set it rips with no hesitation then richen just a bit. Then adjust idle speed with the other screw.

 

[Old2stroke]

Start setting the idle by first finding the lean-best-idle. With the saw running at idle you start turning in the L screw a little bit at a time, if it was running rich, the idle speed should increase as you turn in the screw and the chain will probably start moving. You will reach a point where the engine will want to stall because it is too lean so then back the screw out a bit until the saw runs steady. This is the Lean-best-idle and it too lean for proper operation. With the idle speed adjust screw, NOT the L screw, adjust it until the chain is just moving slowly, now back the L screw out until the chain stops moving and this should set the idle mix rich enough for good acceleration when the throttle is snapped open. If there is hesitation you will have to back the L screw out a bit more. During all this adjusting, the saw may get loaded up with fuel so make several cuts at full throttle to clean it out and get it to operating temperature then recheck the idle as you may have to go through the above process again. If you get it right and if the saw is healthy, it should restart with 1 pull within 5 minutes of being shut off.

 

[Welderman85]

Start setting the idle by first finding the lean-best-idle. With the saw running at idle you start turning in the L screw a little bit at a time, if it was running rich, the idle speed should increase as you turn in the screw and the chain will probably start moving. You will reach a point where the engine will want to stall because it is too lean so then back the screw out a bit until the saw runs steady. This is the Lean-best-idle and it too lean for proper operation. With the idle speed adjust screw, NOT the L screw, adjust it until the chain is just moving slowly, now back the L screw out until the chain stops moving and this should set the idle mix rich enough for good acceleration when the throttle is snapped open. If there is hesitation you will have to back the L screw out a bit more. During all this adjusting, the saw may get loaded up with fuel so make several cuts at full throttle to clean it out and get it to operating temperature then recheck the idle as you may have to go through the above process again. If you get it right and if the saw is healthy, it should restart with 1 pull within 5 minutes of being shut off.

Thank you very much

 

[Chris-PA]

If you open up the muffler you have to retune it or it will be running too lean.

If you open up the muffler a moderate amount and it is effective at increasing air flow, the mixture will be richer. It is only if you open it up very wide so it pulls in fresh air through the exhaust by reversion (bypassing the carb) that it makes the mixture leaner.

 

[Welderman85]

So today I was to get out and test the saw today. I kept jumping the gun and tried to tune it when it was cold. Once she was warm it runs pretty good I still have to work on the idle a little but it runs good and starts good. It's kinda fun trying to learn and tune it.