Ms 880 porting

[Matthew abbott]

Could someone give me some pointers on how to go about porting an ms 880, the timing of the transfers, the timing of the intake and exhaust, I’m trying to get it close to 13000rpm. Also do I need a different carb.

 

[jr27236]

I believe the 880 turns around 8500 rpms stock, I dont think you could get that up to 13000 and if you did I would want to operate it from inside a shark cage! But there may be guys who have attempted or accomplished near that??? I wouldnt with such an expensive saw.

Could someone give me some pointers on how to go about porting an ms 880, the timing of the transfers, the timing of the intake and exhaust, I’m trying to get it close to 13000rpm. Also do I need a different carb.

 

[ironman_gq]

Buy a 660 if you want those RPM's, save the big saw for big wood where no one is in that big of a hurry. You could do it but it's going to take some wild porting and probably a pipe to get there, not sure now long it would hold together though.

 

[blsnelling]

Those RPMs aren't an issue at all with a ported MS880. The rev limiter is in the coil. Depending on the saw, you'll need either a 088 or 361 coil. The carb and intake are more restrictive on the newest version with the stamped stainless steel muffler.

 

[blsnelling]

BTW, 084s and 088s turned something like 12,500 before they threw limited coiled on them, so 13,000 isn't a reach at all, even in a dedicated work saw.

 

[Stihl 041S]

BTW, 084s and 088s turned something like 12,500 before they threw limited coiled on them, so 13,000 isn't a reach at all, even in a dedicated work saw.

And when you have a breathed on 084........you have confidence you can handle most things you should encounter.
If ya got the biscuits to use it. Lol

 

[blsnelling]

 

[blsnelling]

 

[67L36Driver]

BTW, 084s and 088s turned something like 12,500 before they threw limited coiled on them, so 13,000 isn't a reach at all, even in a dedicated work saw.

From my local Stihl tec: 10,500 with the Walbro and 11,000 with the Tilly. Or vice versa.

I’d tune it for 10,000 and call it good. Rod bearing don’t like much abuse on them from what I’ve observed.

 

[blsnelling]

If it's a newer one, you'll not be able to tune to those RPMs anyway since they're rev limited. The only way to time thet is in the cut.

 

[Matthew abbott]

Those RPMs aren't an issue at all with a ported MS880. The rev limiter is in the coil. Depending on the saw, you'll need either a 088 or 361 coil. The carb and intake are more restrictive on the newest version with the stamped stainless steel muffler.

My apologies for taking so long to reply had a super busy weekend. I did replace the stock coil with a ms441 coil I think those are good to 13500, I did some porting on the old cylinder and drilled the muffler as far as I’ve safely gotten it was 12200. Would you happen to know any further details about what carb and intake to use, or if I could just replace the jet in the newer style carb.

 

[Matthew abbott]

Did you do the port work on this saw, I’m new to porting saws and wondering if you knew someone that did it, or if you have a few pointers on how you went about doing it

 

[Chainsaw Jim]

There's lots of good advice about porting the ms880 around a couple forums, but a person needs to know how to port saws the right way before considering this work on the most expensive production saw on the market.

 

[blsnelling]

There's lots of good advice about porting the ms880 around a couple forums, but a person needs to know how to port saws the right way before considering this work on the most expensive production saw on the market.

Exactly. I can't just "tell you how" to port a saw. It's more or less a learned art/skill.

 

[Matthew abbott]

There's lots of good advice about porting the ms880 around a couple forums, but a person needs to know how to port saws the right way before considering this work on the most expensive production saw on the market.

Yea, true, I’d like to start learning how to port and how to get consistent with it. I did some practice on the old cylinder due to it having some scoring and got a gain of 800-900 rpm, the unit didn’t would only hit around 11300 or so. But I’m probably not going to port the new cylindermay send it to get that done, but would like to learn how for future projects.

 

[blsnelling]

Read every thread you can find on porting. Develop a game plan for the saw you want to build. Show your work and get honest feedback. Make changes accordingly.

As already said, I wouldn't learn on a 880. I started with a 260 and worked my way up.

There's a thread here somewhere about the carb and intake changes.

You're still rev limited with the 441 coil. A 361 will fix that.

 

[user 122190]

I consider myself a self taught and now competent gunsmith. Nothing beats experience, and until you have it, going slow protects you from making a costly mistake. I've done lots of trigger jobs, prepped them for finishing, replaced worn or damaged springs, etc. I figure worst case, I can pay someone to screw it up, or screw it up myself and learn something while I'm at it.

Yea, true, I’d like to start learning how to port and how to get consistent with it. I did some practice on the old cylinder due to it having some scoring and got a gain of 800-900 rpm, the unit didn’t would only hit around 11300 or so. But I’m probably not going to port the new cylindermay send it to get that done, but would like to learn how for future projects.

 

[Matthew abbott]

Thanks for the help everyone, he’s gonna use the saw like it is for a while, I’m gonna put a slightly rich tune on it. While it’s gone I’m gonna do some practice porting, by the time it comes back if I’m not comfortable trying it again I’ll send it off to chainsaw Jim or someone local if there is one. Thanks again

 

[Stihl 041S]

I consider myself a self taught and now competent gunsmith. Nothing beats experience, and until you have it, going slow protects you from making a costly mistake. I've done lots of trigger jobs, prepped them for finishing, replaced worn or damaged springs, etc. I figure worst case, I can pay someone to screw it up, or screw it up myself and learn something while I'm at it.

And it can be even worse with a gunsmith. Ruin an 880 cylinder.......big deal.
Screw up a trigger job and some one can die.
10 years down the road.
I worked with a great gunsmith. The crap that came in that was repaired or had to be trashed because some one was learning on someone else’s revolvers.

 

[user 122190]

That is the problem. People are afraid of guns, so they won't attempt to do even the simple things. I've seen crappy work, and I don't recommend it. Just saying...

And it can be even worse with a gunsmith. Ruin an 880 cylinder.......big deal.
Screw up a trigger job and some one can die.
10 years down the road.
I worked with a great gunsmith. The crap that came in that was repaired or had to be trashed because some one was learning on someone else’s revolvers.