MS461 big end bearing

[123465a]

Hi all,

I bought a used MS461 a while back that had clearly been well used before I got it. Decided that it was worth it as it’s only going to be used for firewood and not all day everyday.

It ran fine but knowing the piston was scored I decided it’s time to take a better look before it got too bad and make a list of parts to replace whilst it’s in pieces.

Which leads me to the big end bearing and what is normal play. There is visible radial play in the big end which is not what I’d expect to see, searching the forum the consensus seems to be the same but there is also conflicting information out there saying some play is normal.

I took a video of the play, can anyone confirm this is normal or worn out?

 

[Rich Fife]

As long as there isn't any up and down Movement of the rod on crank/bearing, it should be fine.

 

[dall]

Hi all,

I bought a used MS461 a while back that had clearly been well used before I got it. Decided that it was worth it as it’s only going to be used for firewood and not all day everyday.

It ran fine but knowing the piston was scored I decided it’s time to take a better look before it got too bad and make a list of parts to replace whilst it’s in pieces.

Which leads me to the big end bearing and what is normal play. There is visible radial play in the big end which is not what I’d expect to see, searching the forum the consensus seems to be the same but there is also conflicting information out there saying some play is normal.

I took a video of the play, can anyone confirm this is normal or worn out?

no heat marks like usual but bearing is wore out it seems with the up and down play
the 461 shares crank with the 046 and 460

 

[Duce]

Hi all,

I bought a used MS461 a while back that had clearly been well used before I got it. Decided that it was worth it as it’s only going to be used for firewood and not all day everyday.

It ran fine but knowing the piston was scored I decided it’s time to take a better look before it got too bad and make a list of parts to replace whilst it’s in pieces.

Which leads me to the big end bearing and what is normal play. There is visible radial play in the big end which is not what I’d expect to see, searching the forum the consensus seems to be the same but there is also conflicting information out there saying some play is normal.

I took a video of the play, can anyone confirm this is normal or worn out?

That does not look good to me. Sliding side to side ok, up and down movement is bad movement. Have seen a rod bearing go bad and blow cylinder through it top. Bolts left in case, glad I was not running it.

 

[Rich Fife]

the 461 shares crank with the 046 and 460

The only differences that I have seen between the 046, 460 and 461 cranks besides the suffixes are the chamfers on the counter weights.
Edit: might be slightly different in weights a couple grams or so???? I should've weighed my cranks.

 

[huskihl]

Crank is shot

 

[drf256]

Toast

 

[maulhead]

The only differences that I have seen between the 046, 460 and 461 cranks besides the suffixes are the chamfers on the counter weights.
Edit: might be slightly different in weights a couple grams or so???? I should've weighed my cranks.

The cranks used in later saws like, 460 / 461 have reliefs or cutouts (not sure the correct term) on the big end of the rod, to allow more oil to get to the bearing. 046 cranks don't have the cut outs. They did the same thing with 044 to later 440's.

 

[qurotro]

The big end looks blued(overheated) to me.

 

[123465a]

Thanks for the replies!

The rod has gotten hot at some point as it’s discoloured but I assumed this was from manufacturing heat treatment process and not from the saw running?

Looks like It’ll be getting a new crank, bearings and seals etc.

 

[pwheel]

OEM cranks are expensive and generally tough to kill; are you absolutely positive that there is no vertical play in the bearing, just side/side? The video isn't clear enough.

 

[123465a]

I first noticed it by moving the flywheel back and forwards, with the piston stationary in the bore you can move the flywheel back and forward a small amount and hear the tapping noise. Initially I thought it was the piston pin but that is fine.

It’s not the easiest thing to film but will see if I can get a better video or measure it with a dial gauge

 

[Rich Fife]

OEM cranks are expensive and generally tough to kill; are you absolutely positive that there is no vertical play in the bearing, just side/side? The video isn't clear enough.

It was hard for me to see it too... but, I was in a shop with bright overhead lights. You can see a little up and down movement, and discoloration on the rod and crank.

 

[pwheel]

I first noticed it by moving the flywheel back and forwards, with the piston stationary in the bore you can move the flywheel back and forward a small amount and hear the tapping noise. Initially I thought it was the piston pin but that is fine.

It’s not the easiest thing to film but will see if I can get a better video or measure it with a dial gauge

While the tapping noise is concerning, you might double check by moving the rod up & down at different points of the crank rotation. I wonder about the rings tapping against the piston lands.

 

[huskihl]

While the tapping noise is concerning, you might double check by moving the rod up & down at different points of the crank rotation. I wonder about the rings tapping against the piston lands.

He’s moving the rod up and down in the video. That is what the play is

 

[farminkarman]

He’s moving the rod up and down in the video. That is what the play is

That is what I saw in the video too.

 

[Wonkydonkey]

I see the same up and down play while it’s at tdc, and that means that crank is knackered .

 

[qurotro]

Brand new crank is not blued on either end of the rod. Just don’t ask me why I know..

 

[123465a]

Managed to get a better video, I feel like it’s pretty obvious in this one. Tried moving the rod left and right to see if there was any difference, if there was any it was minimal.

 

[redline4]

It's trash.
Looks rather dry in there too.