MS461 help please

[Michael Rupley]

So this is a 2015 model that was just brought in and you think the jet is suddenly suspect. Hummm??

 

[Bigmac]

So this is a 2015 model that was just brought in and you think the jet is suddenly suspect. Hummm??

The plug looks lean in the first pick, but he is saying it won’t hit 13500 rev limiter at one turn out, who knows what the tune was before he trimmed the tab, if it has the bigger jet it would need to be tuned differently that a small jet, would it not? Once the limiters are trimmed the jet makes a difference! I have seen a bunch of ms440 that once trimmed were 1/4 out or 1-1/2 turns based on jet size, same with ms660’s they had several different jets. So I believe it makes a difference on the final basis tune, if it had the big jet, he may only need to be 1/2 -1 turn out especially if it has the tiny stock single outlet.

The op hasn’t posted a video, or taken many offers for free coils, so it spit balling time! lol I have a 461, and am in Oregon, I am willing to help the op, if he wants it, if he wants to swing by, it’s a drive, he can try my carb and coil if he wants

I would try leaning it out, I believe it should tune around 14.5 with an unlimited 460 coil so if it hasn’t hit the rev limiter then it isn’t lean enough.

 

[Bigmac]

I did miss that the op said he could lean the h screw all the way and not much change, I agree with mike on the metering lever, double check that, and if the kit you used was cheap and the metering spring was China, that could be a problem too.

And to the op, did you test the saw in wood when you got it? Has your changed made improvements?

 

[Stump Shot]

I would want to pop the cover off the muffler and take a look at the condition of the piston and rings for peace of minds sake of nothing else.

 

[Stackowood]

I will try another Walbo carb kit and double check the metering lever. Also have a coil on the way. Thanks.

 

[sawmikaze]

I will try another Walbo carb kit and double check the metering lever. Also have a coil on the way. Thanks.

I mailed it this morning.

 

[MustangMike]

Any updates???

 

[Stackowood]

I'm hoping to run it tomorrow with the new coil, and then I'll report back. Checked the carb again and the metering lever is right on, with no leak at the needle.

 

[MustangMike]

Sometimes, it is the spring. If rebuilt, with a different spring, may want to put the original back in (if you still have it).

 

[Stackowood]

I ran the saw today with the new coil, ran pretty much the same. It seems rich at no load and it will run up to 13,500 with the H needle all the way in, but then it seems to run out of fuel when you load it up in a cut.

New carb on order. If I don't end up needing it for this saw I'll use it on another at some point.

 

[Bigmac]

I ran the saw today with the new coil, ran pretty much the same. It seems rich at no load and it will run up to 13,500 with the H needle all the way in, but then it seems to run out of fuel when you load it up in a cut.

New carb on order. If I don't end up needing it for this saw I'll use it on another at some point.

What makes you think it’s running rich? It should be hitting the rev limiter at 13.5k. If you turn the h screw to a 1/2 turn out dose it still hit 13.5k?

 

[junkman]

Pull the cylinder cover and check the base bolts on the jug ,i have seen these jugs break down there,may not be the problem ,but easy to check.

 

[Wonkydonkey]

This is gettin interesting, it seems so simple but it’s so difficult..

Video.. needed

 

[Adirondackstihl]

Pressure test that carb.
If you can bury the H circuit needle with no RPM change, it’s getting fuel from somewhere else...... leaking Welch plug mayhaps

 

[huskihl]

Pressure test that carb.
If you can bury the H circuit needle with no RPM change, it’s getting fuel from somewhere else...... leaking Welch plug mayhaps

That carb has the circuit where 80%ish of the fuel goes through the main jet and 20% goes through the H screw. It'll probably run like that for awhile...although it might be pretty lean

 

[MustangMike]

Even if the lever is adjusted correctly, if that metering spring is bad, that could be it.

 

[Adirondackstihl]

That carb has the circuit where 80%ish of the fuel goes through the main jet and 20% goes through the H screw. Itll probably run like that for awhile...

My sorry
No bueno

 

[Stackowood]

Even if the lever is adjusted correctly, if that metering spring is bad, that could be it.

I didn't keep the old spring, but I use genuine OEM carb kits.

 

[Stackowood]

What makes you think it’s running rich? It should be hitting the rev limiter at 13.5k. If you turn the h screw to a 1/2 turn out dose it still hit 13.5k?

When the H needle is half way out it is running around 12500-12800, so fairly rich.

 

[MustangMike]

Well, you got me … se let us know when you figure it out.

Is carb replacement next?

I had an Asian 440 Big Bore I could not figure out (would not run), so after a few carbs, coils, plugs and fuel filters I just replaced the whole tank handle, and it was OK. Likely it was either the fuel line or tank vent, but I don't care, it runs now!