400.1 first impression

[lehman live edge slab]

Does the ms 400.1 still blow or is it ok now ?

Worse yet it sucks and blows, sucks in fuel and blows out exhaust.

 

[Duane(Pa)]

What blows is that they’re not here in the USA to be “bought’n”

 

[drf256]

Have you ever seen the exhaust outlet on a Stihl 260? It’s about the diameter of a pencil… I think restrictions are their go-to for reducing noise and emissions.

They’ve clearly been doing some work with acoustics.

Most of the newer Stihls have baffles the twist the exhaust after it exits the cylinder. When there wasn’t enough room to accomplish their goal, they started the twist in the exhaust port (462).

The noise canceling effects of colliding acoustic waves are being taken advantage of. Most of the newer mufflers place the outlet as far back in the can as possible. They are also flowing more and making less decibels.

 

[jurchybald]

Been living with 400.1 for months now. All I can say is I hate it. It runs so fuggin lean I don't know when it's running out of fuel. Stock or ported. So this week I drilled every hole on carb I ever heard people drill. Tomorrow I'm buying new carb. Can't wait for 564xp.

 

[jurchybald]

Other than that it has a torq of 500i and shape of 261. People here love it

 

[lehman live edge slab]

Been living with 400.1 for months now. All I can say is I hate it. It runs so fuggin lean I don't know when it's running out of fuel. Stock or ported. So this week I drilled every hole on carb I ever heard people drill. Tomorrow I'm buying new carb. Can't wait for 564xp.

Can’t be that lean because if it was it wouldn’t have made it through the tank.

 

[bwalker]

Been living with 400.1 for months now. All I can say is I hate it. It runs so fuggin lean I don't know when it's running out of fuel. Stock or ported. So this week I drilled every hole on carb I ever heard people drill. Tomorrow I'm buying new carb. Can't wait for 564xp.

How are you determining its lean? If it was indeed lean torque, would be diminished. How does it perform?

 

[Duane(Pa)]

I’ve never heard an mtron four stroke. They go right to the limiter…
Lest we forget this is about emissions.

 

[jurchybald]

It's fine in the cut. Out of cut and idle is like it's running out of fuel all the time. Something that bothers me personally.

 

[Woodpecker]

I think it’s more important now than ever to run 40:1 or better with modern saws.

 

[redneckhillbilly]

It's fine in the cut. Out of cut and idle is like it's running out of fuel all the time. Something that bothers me personally.

when you say lean, is like actually lean enough to make your eyes water.

 

[redneckhillbilly]

im wondering if they run them lean in order to keep them from cooling down during idle.

 

[DND 9000]

Been living with 400.1 for months now. All I can say is I hate it. It runs so fuggin lean I don't know when it's running out of fuel. Stock or ported. So this week I drilled every hole on carb I ever heard people drill. Tomorrow I'm buying new carb. Can't wait for 564xp.

They aren`t set up to lean. If this would be the case they would blow up en masse. Without proper testing equipment you can`t know if it is lean or not. (exhaust gas probe, for lambda testing). Yes these engines can run lean due to air leaks, clogged filters or misadjusted inlet control levers. But that would not be the fault of m-tronic, these are maintenance or mechanical failures.

And drilling and destroying a fairly new carburetor is in my opinion just stupid, just for the guess that the engine is running to lean. If you are really worried about it, give the saw to your dealer for a complete check. If there is really something wrong, the dealer will take care of it.

 

[bwalker]

I’ve never heard an mtron four stroke. They go right to the limiter…
Lest we forget this is about emissions.

Let's not forget 4 stroking is so rich the engine is misfiring. Its an easy way for guys to tune to, but not great way performance wise.
The Mtronic and Autotune saws I have ran always feel bang on and exactly like a tuned my carbed saws.

 

[bwalker]

I think it’s more important now than ever to run 40:1 or better with modern saws.

Or even 32:1.
Strato really changed alot in this regard. As you increase fuel economy you also decrease lubrication.

 

[bwalker]

It's fine in the cut. Out of cut and idle is like it's running out of fuel all the time. Something that bothers me personally.

Try a reset?

 

[EFSM]

Been living with 400.1 for months now. All I can say is I hate it. It runs so fuggin lean I don't know when it's running out of fuel. Stock or ported. So this week I drilled every hole on carb I ever heard people drill. Tomorrow I'm buying new carb. Can't wait for 564xp.

Sounds like a pop of pressure may be too high, a little bit like the Husqvarna 550s and 562. Some of them are over 30 psi from stock.

 

[jacktheripper]

Sounds like a pop of pressure may be too high, a little bit like the Husqvarna 550s and 562. Some of them are over 30 psi from stock.

Most are well over 40 in my experience

 

[EFSM]

Most are well over 40 in my experience

My gauge maxes out at 30. Not surprised if they are 40.

 

[Woodpecker]

Or even 32:1.

That would be better