Help me mod this Stihl MS460

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DowneyTree

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I picked up this beauty Stihl MS460 Magnum this week a couple hours from home, and so far it seems to have been well worth the drive. The compression test read 164psi, and it pulls great. I already have a MS461 for my small business, and am looking for some suggestions in modifying the 460.

I've read that a dual port exhaust is a must-have for starters, and am looking for suggestions on where to order one from.

I was planning on sending it to be Walkerized, but the shipping both ways across is expensive..

Thank!
IMG_8259.jpg IMG_8260.jpg
 
I don’t know about a 460 but on a 440 the basics are:
Muffler mod
Base gasket delete
Timing advance

That nets a huge difference for basically no cost unless you buy the muffler or don’t have a tool needed.
 
I don’t know about a 460 but on a 440 the basics are:
Muffler mod
Base gasket delete
Timing advance

That nets a huge difference for basically no cost unless you buy the muffler or don’t have a tool needed.
Did you go with an air filter kit as well? I'm assuming a carb adjustment was needed too.
 
Did you go with an air filter kit as well? I'm assuming a carb adjustment was needed too.
I have not even really looked into that. I’m not sure if that’s a good thing for a work saw or not, someone more knowledgeable will come along soon. The carb will need adjustment checked pretty much every time you touch anything, it will crank and run, but you probably need to add fuel after power increasing mods.
 
The HD2 air filter, even the Chinese version, is way better than the original.
The dual port cover is also available aftermarket.

Quick hyjack!
Is that what comes with the huztl kits is their hd2 clone? I have one on the shelf that it appears is too thick and the stud is too short to work with it.
Do you run a prefilter on them?
 
Well tomorrow is the stage one of giving this 460 Magnum some more bite, or supposed to be if my parts show up..

All I have coming so far, is a dual-port muffler cover, full wrap handle, new felling dogs, and a Stihl EDT-9 tach to tune the carb after the muffler mod (I'm also going to gut the inside of the stock exhaust). I've read lots of great posts here on how to tune the carb (have my drywall screws to remove the limiter caps and everything), but if someone has some tips, or can share any other sources to follow along with, it would be greatly appreciated.

I'll post pictures/videos as I go
 
You can’t use the tach to tune it after you modify it. The factory settings will no longer work.

Tune by ear, always the safest. Use the tach as a reference point and not an absolute.

The 460/046 generally responds well to simple mods, especially the later model 460 jug, they are already nearly factory ported with more symmetric/larger ports than their 046 brothers.

Open the inner muffler baffle a bit by lowering the center of it. You really need to open the PTO opening a bit more and add a second deflector to the Fly side. You can add a DP front cover, but they are noisier.

Try a base gasket delete with a suitable sealant. I believe you should yield a safe squish IIRC, but it’s been a long time since I took one apart and didn’t fully port it. Make sure you check squish.

Timing advance works well also. Around .025 off the right side of the key as you view it on the saw.

They are great saws. Do the above and you’ll likely be happy and beat up your 461

@huskihl and/or @Chainsaw Jim are both solid guys that can help get that puppy ported for you.

Here’s how I do the muff on them. I wrap the PTO side after I open it to prevent the staining on the case. And here’s a vid of the saw the muff went on. Saw is just built, so it’s pretty fat. It’s comfortable now at around 14500.

1861AF9A-FB0A-479E-9626-C525A1F49E70.jpeg 0E90DBB4-0B23-4435-B066-6DD0394487FE.jpeg C8ACDDEE-FD2C-4C6A-9201-2471FC51F7E5.jpeg 0A4830A2-0F6D-4AE2-AD88-37999D247F20.jpeg E37255F6-DFAD-48A0-BDF5-C785F87A376E.jpeg


 
Quick hyjack!
Is that what comes with the huztl kits is their hd2 clone? I have one on the shelf that it appears is too thick and the stud is too short to work with it.
Do you run a prefilter on them?

Yea, that's what comes on Huztl kits. Yours may be for a different model.

I'd like to have a prefilter but have not gotten around to it.
 
You can’t use the tach to tune it after you modify it. The factory settings will no longer work.

Tune by ear, always the safest. Use the tach as a reference point and not an absolute.

The 460/046 generally responds well to simple mods, especially the later model 460 jug, they are already nearly factory ported with more symmetric/larger ports than their 046 brothers.

Open the inner muffler baffle a bit by lowering the center of it. You really need to open the PTO opening a bit more and add a second deflector to the Fly side. You can add a DP front cover, but they are noisier.

Try a base gasket delete with a suitable sealant. I believe you should yield a safe squish IIRC, but it’s been a long time since I took one apart and didn’t fully port it. Make sure you check squish.

Timing advance works well also. Around .025 off the right side of the key as you view it on the saw.

They are great saws. Do the above and you’ll likely be happy and beat up your 461

@huskihl and/or @Chainsaw Jim are both solid guys that can help get that puppy ported for you.

Here’s how I do the muff on them. I wrap the PTO side after I open it to prevent the staining on the case. And here’s a vid of the saw the muff went on. Saw is just built, so it’s pretty fat. It’s comfortable now at around 14500.

View attachment 715127 View attachment 715128 View attachment 715129 View attachment 715130 View attachment 715131



This helps so much, thanks! I’ve seen guys fully remove the baffle inside the muffler. Is this a bad idea, or just not necessary in your opinion?

Also, just to verify, it’s best to put the limiter caps back in after adjusting the carb, correct? If that’s the case, may order backups now as I’m going to try to get them out with a screw..

Thanks again :cheers:
 
Well tomorrow is the stage one of giving this 460 Magnum some more bite, or supposed to be if my parts show up..

All I have coming so far, is a dual-port muffler cover, full wrap handle, new felling dogs, and a Stihl EDT-9 tach to tune the carb after the muffler mod (I'm also going to gut the inside of the stock exhaust). I've read lots of great posts here on how to tune the carb (have my drywall screws to remove the limiter caps and everything), but if someone has some tips, or can share any other sources to follow along with, it would be greatly appreciated.

I'll post pictures/videos as I go
get the 70mm semi fixed jet for that plugged up EPA carb
 
I bought a 460 off ebay a couple of years ago and this is what had been done to it. I run a 20 inch bar on it and it is nasty. Hope this helps.
f6a7a6a9c1c6e7dfd39db80acb3a282a.jpg


Sent from my SM-G965U1 using Tapatalk
 
According to the test below removing the baffle makes it cut slower. He used a 461 but the baffle is the same design as the 460.



This type of baffle is essentially a really short head pipe. Sure the timing on the primary wave will be off (a proper head tube to an expansion chamber for this size engine and target rpms would be much longer) but there's harmonics. Stihl put it in there and didn't make it a restrictive type like the 660 has for a reason.

If you want to experiment with removing it, an aftermarket muffler that doesn't have the baffle is cheaper than buying a new stock back half when you decide you want to try the baffle again.
 
According to the test below removing the baffle makes it cut slower. He used a 461 but the baffle is the same design as the 460.



This type of baffle is essentially a really short head pipe. Sure the timing on the primary wave will be off (a proper head tube to an expansion chamber for this size engine and target rpms would be much longer) but there's harmonics. Stihl put it in there and didn't make it a restrictive type like the 660 has for a reason.

If you want to experiment with removing it, an aftermarket muffler that doesn't have the baffle is cheaper than buying a new stock back half when you decide you want to try the baffle again.

It's not a 1-size-fits-all kind of thing. If Julian was cutting 12" wood, his 461 likely would've been faster without the baffle. I don't believe the saw was ported, either, which likely would've been faster without the baffle also.
 
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