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Please help me buy a Stihl MS461...information request

Started by woodworker9, April 29, 2017, 10:50:24 AM

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khntr85

I ordered a dual port just to try on my stock 461......I have read were it doesn't help much....I guess if it just cuts down on some heat it would be worth it???

Tony01

Had my MS461 for 12 months from brand new here in Australia till it needed a full rebuild since it was rebuilt I can say the power has died in the backside forever bogging down and now having to put pressure for it to cut quickly as from new I was hanging off it as it wanted to pull the chain and myself through the log I regret getting it rebuilt and should have just traded in the saw is nothing but a canoe anchor now :(

PNWRusty

Quote from: Tony01 on July 08, 2017, 02:01:44 AM
Had my MS461 for 12 months from brand new here in Australia till it needed a full rebuild

Why did such a new saw need a full rebuild?

khntr85

Quote from: Tony01 on July 08, 2017, 02:01:44 AM
Had my MS461 for 12 months from brand new here in Australia till it needed a full rebuild since it was rebuilt I can say the power has died in the backside forever bogging down and now having to put pressure for it to cut quickly as from new I was hanging off it as it wanted to pull the chain and myself through the log I regret getting it rebuilt and should have just traded in the saw is nothing but a canoe anchor now :(

What happened to the saw that required a rebuild??

Tony01

had a rattle in the big end and score on the piston and bore the dealer says it was from using a 8 tooth sprocket when from factory it had a 7 tooth sprocket it has never been the same,,,,,, they replaced only the piston and honed the bore which i recond they should have replaced as now the compression will be down a little they say it wont effect the compression but the saw did cut 450 tonne of iron bark and yellow box Australian hard wood

PNWRusty

Quote from: Tony01 on July 09, 2017, 04:59:15 AM
had a rattle in the big end and score on the piston and bore the dealer says it was from using a 8 tooth sprocket when from factory it had a 7 tooth sprocket it has never been the same,,,,,, they replaced only the piston and honed the bore which i recond they should have replaced as now the compression will be down a little they say it wont effect the compression but the saw did cut 450 tonne of iron bark and yellow box Australian hard wood

Sounds more like pre-detonation from old gas or maybe accidently run with without oil. But absolutely silly to blame it on an 8 tooth sprocket! When these saws die early it's almost always human error (and I'm not going to include choosing an 8 tooth sprocket as human error).

joe_indi

Quote from: Tony01 on July 09, 2017, 04:59:15 AM
had a rattle in the big end and score on the piston and bore the dealer says it was from using a 8 tooth sprocket when from factory it had a 7 tooth sprocket .......
:o
Here I replace the 7 tooth rim with the 8 tooth rim to prevent big end burn outs.
Maybe in your part of the woods the 461 behaves differently, but here the big ends burn out from Under load that is going full rev with blunt chains.
The standard bar size here is 18" with full chisel chains.
So, I replace the stock 7T rims with the optional 8T rims.
In many cases I also replace the stock ignition module (it has ignition timing advance) with the module from the 460 (no ignition timing advance).
If the owner cannot afford a coil replacement, I use a mini hacksaw to trim off the third pole of the module (it controls the timing advance)
But after that you will need to tune from scratch with the limiter caps removed.
And remove some of the restriction of the muffler exit hole (enlarge it to old 460 dimension)
The end result is a fantastic saw that runs like a 460 but with a helluva lot of torque
My 'Guinea Pig' 461 even handles a 16" Duromatic guidebar running a 46RS chain, something that would kill a 460

Tony01

Quote from: PNWRusty on July 09, 2017, 11:07:05 AM
Quote from: Tony01 on July 09, 2017, 04:59:15 AM
had a rattle in the big end and score on the piston and bore the dealer says it was from using a 8 tooth sprocket when from factory it had a 7 tooth sprocket it has never been the same,,,,,, they replaced only the piston and honed the bore which i recond they should have replaced as now the compression will be down a little they say it wont effect the compression but the saw did cut 450 tonne of iron bark and yellow box Australian hard wood

Sounds more like pre-detonation from old gas or maybe accidently run with without oil. But absolutely silly to blame it on an 8 tooth sprocket! When these saws die early it's almost always human error (and I'm not going to include choosing an 8 tooth sprocket as human error).

that is something i am really picky with as the saw is my livelyhood   "no saw no income" even through the hot summer months i run 36/1 mix in all my saws 390 husky out performs the 461 after the rebuild but before the rebuild the sthyl 461 was eating the husky to the point i was about to sell it and buy another 461 the score on the bore they say is usual for a saw that has cut that amount of wood in that period of time "450 tonne cut into 400ml lenghts all by saw"

Tony01

Quote from: joe_indi on July 10, 2017, 01:34:49 AM
Quote from: Tony01 on July 09, 2017, 04:59:15 AM
had a rattle in the big end and score on the piston and bore the dealer says it was from using a 8 tooth sprocket when from factory it had a 7 tooth sprocket .......
:o
Here I replace the 7 tooth rim with the 8 tooth rim to prevent big end burn outs.
Maybe in your part of the woods the 461 behaves differently, but here the big ends burn out from Under load that is going full rev with blunt chains.
The standard bar size here is 18" with full chisel chains.
So, I replace the stock 7T rims with the optional 8T rims.
In many cases I also replace the stock ignition module (it has ignition timing advance) with the module from the 460 (no ignition timing advance).
If the owner cannot afford a coil replacement, I use a mini hacksaw to trim off the third pole of the module (it controls the timing advance)
But after that you will need to tune from scratch with the limiter caps removed.
And remove some of the restriction of the muffler exit hole (enlarge it to old 460 dimension)
The end result is a fantastic saw that runs like a 460 but with a helluva lot of torque
My 'Guinea Pig' 461 even handles a 16" Duromatic guidebar running a 46RS chain, something that would kill a 460

here standard bar is 20" with full chisel chain  on the other notes could you send me a pm of the module part numbers and info on the mods as if it helps this saw perform i am all up for it cheers in advance Tony

joe_indi

There is nothing much to pm about.
All that you would need are the following:
Muffler try the Magnum # 1128 140 0616
Ignition module # 1122 400 1314
You will need to pull out the limiter caps on the carb to re-tune both L and H after you have the above muffler and ignition module fitted
You could use these images from my gallery to guide you on getting the limiter caps out.








Tony01

thank you first thing in the morning down to the shop to order these in and yes the pictures are a great help  :laugh: ;D

PNWRusty

Quote from: Tony01 on July 10, 2017, 04:21:56 AM
that is something i am really picky with as the saw is my livelyhood   "no saw no income" even through the hot summer months i run 36/1 mix in all my saws 390 husky out performs the 461 after the rebuild but before the rebuild the sthyl 461 was eating the husky to the point i was about to sell it and buy another 461

Was the big end bearing replaced (or what caused the rattle in the big end)? If the big end bearing was shot, it's normal for there to be a little scoring. I disagree that cutting a lot of wood results in scoring. Scoring is caused by specific things or failure of other parts.

A lot of guys run extra oil in their saws figuring "if a little is good, more must be better, right?"

This is misguided (yes, it is possible to "love" your saw too much). Oil lowers the octane rating of the fuel mix. Adding extra oil can lower the octane too much. It also is known to cause additional carbon buildup. Carbon buildup can increase the compression. Both conditions can lead to detonation, and even more so if the engine is run a little lean. Octane also decreases when fuel ages. Detonation destroys big ends and leads to scoring of the cylinder. A 36:1 fuel/oil mix is not going to prevent damage from detonation, it just makes detonation more likely.

Regardless of whether your recent trouble was caused by detonation, I recommend you run 50:1 synthetic oil and keep the mix fresh. 

barbender

Too many irons in the fire

PNWRusty

Quote from: barbender on July 12, 2017, 09:20:52 PM
How does more oil lower the octane rating?

The simple answer is that oil has a lower octane rating than gasoline. The more you add, the easier the mixture will detonate. I've seen, as a rough estimate, a 1 point octane drop for each percent of oil added. But octane rating is complicated business and is not straightforward at all. If you want to know more about the complicated chemistry of octane, this is a good link:

http://www.sciencedirect.com/science/article/pii/S0360128516300570#bbib0177

To compound the octane lowering problem, oil dilutes the fuel which leans the engine (if not tuned for the higher oil content). If you want to know what the experts at Madsens say on the subject of pre-mix for pro saws, this is a good link:

http://www.madsens1.com/saw_fuelmix.htm

The experts at Madsens Saw and Supply have torn down, rebuilt and repaired thousands of saws for PNW loggers over many years and have seen the damaging results of too much oil.

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