STIHL MS 400

[Catfishclark89]

Sorry to revive an old thread here but wanted to share some findings in regards to the oil pump on these ms400’s. I have in the pictures a ms400 oiler (top) and a standard 1/2 wrap 461 oiler (bottom) notice the more pronounced angle on the 461 pump piston? This should indicate more stroke (higher oil flow volume) the control bolts are the same part number. But the pistons have different part numbers. I’m thinking a standard 461 pump may do the trick in wetting a 25” bar. I did do the swap and I’ll see how it does tomorrow.

 

[Mastermind]

Sorry to revive an old thread here but wanted to share some findings in regards to the oil pump on these ms400’s. I have in the pictures a ms400 oiler (top) and a standard 1/2 wrap 461 oiler (bottom) notice the more pronounced angle on the 461 pump piston? This should indicate more stroke (higher oil flow volume) the control bolts are the same part number. But the pistons have different part numbers. I’m thinking a standard 461 pump may do the trick in wetting a 25” bar. I did do the swap and I’ll see how it does tomorrow.

Looking forward to your thoughts after using it some Evan.

 

[lehman live edge slab]

Sorry to revive an old thread here but wanted to share some findings in regards to the oil pump on these ms400’s. I have in the pictures a ms400 oiler (top) and a standard 1/2 wrap 461 oiler (bottom) notice the more pronounced angle on the 461 pump piston? This should indicate more stroke (higher oil flow volume) the control bolts are the same part number. But the pistons have different part numbers. I’m thinking a standard 461 pump may do the trick in wetting a 25” bar. I did do the swap and I’ll see how it does tomorrow.

Should work well, maybe I’m wrong but i thought a lot of guys put 460/461 oilers in the 362’s and now the 400. They definitely are stingy on oil with a 25”

 

[Catfishclark89]

Should work well, maybe I’m wrong but i thought a lot of guys put 460/461 oilers in the 362’s and now the 400. They definitely are stingy on oil with a 25”

They probably are. I’m just late to the party as usual

 

[sawmikaze]

Sorry to revive an old thread here but wanted to share some findings in regards to the oil pump on these ms400’s. I have in the pictures a ms400 oiler (top) and a standard 1/2 wrap 461 oiler (bottom) notice the more pronounced angle on the 461 pump piston? This should indicate more stroke (higher oil flow volume) the control bolts are the same part number. But the pistons have different part numbers. I’m thinking a standard 461 pump may do the trick in wetting a 25” bar. I did do the swap and I’ll see how it does tomorrow.

That's odd because the offset where it meets the pump on the screw is different from the 461R compared to the 400, maybe it's only the standard model 461 pump bolt That's the same.

Adding the bolt alone increases output, I've done it in quite a few saws.

 

[sawmikaze]

Looking forward to your thoughts after using it some Evan.

You shared this picture in the 261 oil pump mod thread.



461R bolt vs a 261 bolt.

 

[Catfishclark89]

That's odd because the offset where it meets the pump on the screw is different from the 461R compared to the 400, maybe it's only the standard model 461 pump bolt That's the same.

Adding the bolt alone increases output, I've done it in quite a few saws.

Yes I’ve swapped the control bolts in the 461’s and it increased the oil output quite a lot. I just had a complete standard 461 oil pump laying around and was checking the differences. But yeah the 461R control bolt has more offset on the cam to allow that piston to operate in the more open position. Is that what you’re talking about sawmikaze?

 

[drf256]

I‘m sure you guys are right, but I don’t understand how just a control bolt swap increases pump output.

Again, if it’s working in the real world, that’s all that matters.

The pump works by the control bolt limiting the lower portion of the ramp. When it’s wide open, the lower portion can hit the round edge and the full stroke occurs. The stroke (and therefore output) shouldn’t change unless the ramp is changed. IIRC, the slope rides on the area below the cam that’s concentric. The cam is what the piston/shaft tip rides on.

 

[drf256]

If you take a look, you’ll see what I mean. Even if you chopped the cam off completely, the oiler would work at the max the ramp cam move the piston. Changing the control bolt should change nothing unless the ramp is modded to move more with the change.

 

[huskihl]

View attachment 393171

If you take a look, you’ll see what I mean. Even if you chopped the cam off completely, the oiler would work at the max the ramp cam move the piston. Changing the control bolt should change nothing unless the ramp is modded to move more with the change.

I’ve seen where others reported that just the HO control bolt seemed to add more flow. I was assuming there was some slop, or extra room in the stock setup which allowed the piston to travel just a little bit further. Never tried it myself

 

[sawmikaze]

Yes I’ve swapped the control bolts in the 461’s and it increased the oil output quite a lot. I just had a complete standard 461 oil pump laying around and was checking the differences. But yeah the 461R control bolt has more offset on the cam to allow that piston to operate in the more open position. Is that what you’re talking about sawmikaze?

Ya that's what I meant.

 

[Catfishclark89]

Well I tried out the standard 461 pump Saturday with less than stellar results… have HO control bolt on the way. I know for a fact that that mod works alone on the 461 to increase oil flow substantially. Y’all have a good one

 

[WI_Hedgehog]

I had the opportunity to run @julie wolf's MS 400 new outta da box this weekend. She slapped on a new 24" bar/chain (25" in STIHL terms) that @Gentleman at HL Supply set her up with, cranked the oiler to max, and let 'er spin. It oiled, too much actually, which is what she wanted for a new B/C.

You can see the oil building up around the edge of the bar, so it's definitely dumping dinosaur:



(STIHL HP Ultra bar oil)