171 hardley revs and has no power

[motolife313]

Has good compression still but you can hold it wide open and it’s only hitting about 75 percent of its max rpm. Last time I put fuel in it it was none ethanol, is that ok? And I did run it little rich on oil. 1.5 gallons to 5 ounces or 2 bottles. Would this mess with it that much. Bought the saw new this year. Thanks. Plug is black. Didn’t put a new one in yet. Wired brushed it. Hit little higher rpm but stops in wood with almost no pressure. I dumped the gas and put in non ethanol 50.1 and still won’t rev. It started while cutting these tiny apple branches

 

[CausticUC]

I'll ask the obvious question first as nothing was mentioned about it .... you clean the air filter recently?

Black plug - carbon or oil?

 

[motolife313]

Yes not long ago. I took it off and it got worse. Also it runs worse when upside down

not sure. I’ll try a new plug tho

 

[RED-85-Z51]

Spark arrestor screen blocked?

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[CausticUC]

Has someone tried to adjust your carb recently? Increasing airflow should not make it run worse.

 

[motolife313]

No. I tried to make sure the main screw was all the way open since that’s the way they come. And I didn’t check on the screen. Sounds normal at idle but I’ll check

 

[HarleyT]

 

[DND 9000]

It sounds from your description that your saw is tuned to rich. Try to lean it out slightly and see if it gets better. Turn the H screw 1/8 turn to the right and see if it gets better, should have higher revs then. It is good if they come a little bit rich tuned from the factory.

 

[motolife313]

Well it all happend after mixing my gas to rich. I went back To 50.1 and it’s still not reving. I’ll check that screen soon

 

[CausticUC]

Well it all happend after mixing my gas to rich. I went back To 50.1 and it’s still not reving. I’ll check that screen soon

You do see how that is interrelated to the above suggestion about leaning out your carb I hope?

 

[CR888]

Clean the screen with a blowtorch to burn off all the carbon, then correctly mix fresh gas and tune saw. Otherwise it'll happen again.

 

[motolife313]

I’m going to take it to the dealer before I even change the plug. Do I tell them I ran non ethanol or ethanol? I run both. Just don’t want to void the warranty

 

[motolife313]

You do see how that is interrelated to the above suggestion about leaning out your carb I hope?

That’s masking over a problem.

 

[CausticUC]

That’s masking over a problem.

In the context of the 4 parameters for a 2 stroke engine to run properly, I would be curious to hear the logic for the above statement.

 

[motolife313]

Spark plug didn’t do it. The screen looks ok. Not wet or anything. Can’t get it cleaned or new carb so I’ll take it apart and clean it myself. Little new thing is finnikey. It wouldnt run off some good Honda hp2 oil. Had to be the stihl stuff. That was actually the first one I got

 

[CausticUC]

My take is that:

Mixing fuel and oil is a manual process subject to the human element.

Mechanically adjusting the fuel-oil + air mixture compensates for the human variation in the fuel, elevation and the temperature/season the engine is being used in.

A spark issue is unlikely a problem based the described behavior.

Air can be affected at both the intake and exhaust, however that is described as clean.

Mixing and remixing your fuel and oil to compensate for your carb settings is probably on the borderline OCD side of things.

That brings us back to adjusting/tuning the engine to compensate for the fuel+oil and the environment.

Currently, there is no indication of a masked problem per my view of the 4 parameters and how they affect the engine. Which is why I was wondering how you came to the conclusion.

If there is any problem, it is possibly that the saw was never tuned properly by the dealer.

 

[motolife313]

I’m thinking the carb is clogged up possibly. I’ll clean it and get back. The dealer didn’t even know how to start the saw. He said it’s fine to start it on run and not half choke. I start all my saws on full then half. I was hoping he would start it the correct way and leave it on half choke and let it rpm a bit to warm up or else it’s cold blooded since it’s so lean from the factory. This saws runs at about 1/2 rpm on half choke. When I bought it from this dealer they said run it on half choke for 20 sec but no more. I just run it half choke for about 3-5 sec. would have let us no right away but he hit the trigger.

 

[RED-85-Z51]

I’m thinking the carb is clogged up possibly. I’ll clean it and get back. The dealer didn’t even know how to start the saw. He said it’s fine to start it on run and not half choke. I start all my saws on full then half. I was hoping he would start it the correct way and leave it on half choke and let it rpm a bit to warm up or else it’s cold blooded since it’s so lean from the factory. This saws runs at about 1/2 rpm on half choke. When I bought it from this dealer they said run it on half choke for 20 sec but no more. I just run it half choke for about 3-5 sec. would have let us no right away but he hit the trigger.

There isnt a half choke. Choke is down, 1 click up is no choke high idle, squeeze the trigger for low idle.

You only need choke for a pull or two on a fully cold saw, if its warm...one click
Off kill and pull..should start and go to a low idle.



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[motolife313]

Well the winner is Harleyt! I took the carb apart and clean it and same problem, I thought right away it’s gota be that screen then mentioned on here. It was clogged.took it out and runs great now. Revs high idle also when first starting. Thank you for the help guys.
Will it be too lean to run it with no filter screen? The carb h screw is maxed out from the factory so I can’t go any richer on the carb

 

[farmguywithasaw]

Well the winner is Harleyt! I took the carb apart and clean it and same problem, I thought right away it’s gota be that screen then mentioned on here. It was clogged.took it out and runs great now. Revs high idle also when first starting. Thank you for the help guys.
Will it be too lean to run it with no filter screen? The carb h screw is maxed out from the factory so I can’t go any richer on the carb View attachment 869751View attachment 869752View attachment 869753View attachment 869754

It needs to be cleaned every once in a while but the problem is made worse by mixing the oil heavy