MS461 help please

[Stackowood]

I have a MS461 that a customer brought in for low power. 2015 model, fairly low hours 28" bar, great looking piston, all stock, 160 psi, passed pressure check, starts fine, runs fine at no load, set at about 13,200 rpm.

When it came in the air filter and fuel filter were plugged. Replaced plug and fuel filter, cleaned the air filter, replaced the fuel tank vent, and it still has low power even when testing with a 20" bar. It doesn't die in the cut, but you can stop the chain. Have not replaced the lines but they look fine.

Any thoughts on what to look for besides the obvious? Note picture of spark plug. Thanks!

 

[huskihl]

Run it without the air filter and see what it does. Start rich and tune it to the limiter once its warm

 

[Wood Doctor]

Compression is good. You've replaced about everything but the carb. I think that's next unless the muffler's spark screen is partially blocked.

 

[Backtroller]

Is the clutch junk?

 

[Stackowood]

Could be the clutch, I'll check that.

 

[dall]

Could be the clutch, I'll check that.

when stalls the chain does the rpms go way down ?

 

[Bigmac]

Check the spark screen?

 

[dall]

Check the spark screen?

id say spark screen or coil breaking down under a load but spark screen seems like the culprit

 

[~WBF]

usually it's compression when it sacks out in the wood. Obviously that's not the case here. I would go with screen also if the filter was plugged...as mentioned 3 times.

Then ignition 'points' or wire

 

[huskyboy]

Check the fuel filter as well. Almost no one replaces that easy cheap item.

 

[sawmikaze]

Check the fuel filter as well. Almost no one replaces that easy cheap item.

He already did that.

Im goin with the screen or the clutch.

 

[Michael Rupley]

How about the little screen in the Carb?

 

[dall]

He already did that.

Im goin with the screen or the clutch.

if clutch was going bad the rpms would go up while the chain stalled out

 

[~WBF]

He already did that.

Im goin with the screen or the clutch.

Screen yes.
I was thinking possible could be a clutch but usually they won't set up for sh—t?
Stuff I was watched and learned hanging around a friends saw shop that worked on beat sh—t.
Personally have never seen this kinds thing with a clutch I have never had anything but the usually broken or cooked springs



.

 

[Bigmac]

Yes, as also mentioned if the fuel filter is plugged then it’s a good idea to check the fuel screen in the carb.

 

[Stackowood]

I rebuilt the carb, and the screen at the inlet was clean. New OEM fuel filter. Pretty sure I checked the spark screen but will look again.

 

[huskyboy]

A video of it cutting would be helpful

 

[Michael Rupley]

You didn't say your rebuilt the carb. If you did I missed it. Would be nice to know everything if you want help.

 

[Nick060200]

I have a pretty new OEM coil for a 461. I'll send it to you if you want to try that. I would need it back though. Let me know if interested.

 

[Stackowood]

I have a pretty new OEM coil for a 461. I'll send it to you if you want to try that. I would need it back though. Let me know if interested.

Thanks, I may take you up on that. I think I'll run it with the ZAT spark tester and see if it is losing spark under load.