New MS 880 Coil Swap

[tacomatrd98]

New Version MS880 Cylinder Question

Hi guys, First time posting here. i have been following this thread for awhile as I have a new version (stainless muffler) MS880 that runs ike a pig. to the point...

I ordered the intake boot, carb gromet, sealing ring, ht-12e carb and 441 coil and thought I was all set to go. i pulled the saw apart, and when I removed the stock intake boot and found a drilled hole on the bottom of the intake port. it is drilled in the extra aluminum that is covered by the oval shaped new style intake boot. It goes straight through the bottom of the port and ends up in the cylinder wall just below the floor of the intake port. What is this for, will it hurt anything if i run the old style intake boot that doesnt block off this hole?

This is not the first saw I have had apart but definitely the newest and most expensive. I had planned on doing a mild port cleanup on it but with this hole in the port It wont allow me to open up the intake bell to match the boot diameter without grinding ito this hole.

I'm still seeking advice on the above question, however:

Curiosity killed the cat and I put it all together and fired it up. I opened up the stock outlet about 2.5 times its stock size but it is still flowing through the rather small pathway inside the muffler. The outlet is still only about half the size of the exhaust port. I am going to mod it more and most likely use the husky deflector like split-post did.

Saw did not want to start very well. Got it running and had to adjust the L screw out 2.5 turns to make it idle. Got it idling fine and good throttle response. Rev it out and hold it and after a few seconds it lean spikes in rpm as it is running out of fuel and dies. a few pulls to get more fuel into the carb and it fires right back up. WOT and same thing. Its sucking the carb dry. This is a brand new NOS carb from stihl. Last ht-12e made I think. If you order the part number now you get a Walbro WG-13 which has the same small throttle bore as the stock WG-12.

I swapped the stock carb back in and tuned it a little and it runs just fine. Screw settings are close to stock.

I'm thinking the fuel lever/float valve needs adjusted? Sound reasonable? Shouldnt a new carb on a brand new saw be set pretty much on the dot?

Any input/opinions are greatly appreciated.

Thanks,

-AJ

 

[Beer Gut]

1st you didn't need the new carb, at least with what we learned. The stock port on the muffler due to its wrap around channel is terrible, a good dual port is better. Cut the limit caps so you can richen up the H screw. So far I have mine around 13300 RPM and running nice, I can go leaner yet I bet to around 13500. I play with the tune now and then tweaking it in. Im a little rich yet so not worried when I run it. Splitpost would have to respond on the 088 intake boot. But he was looking for more air so I doubt he was sucking his carb dry, and he has the stock one last I knew.

Hope this helps.

 

[tacomatrd98]

What about the hole?

i have both intake boot and carb fitted from the earlier version,i was looking and found more air and fuel in the older parts,the muff is the biggest cork on these saws ,i did run it with the wg12 and smaller boot but it doesn't feel as strong in the cut,since posting i have swapped the ht12 for a ht7,one of the last of the 084 tillys with the intelly bit fitted,it now feels stronger in the cut and has better feel when tuning

Thanks for the replies fellas. Still begs the question, What is with that stupid hole in the bottom of the intake port? Did either of you guys saws have them?



It is obvious when you compare the old and new parts that the old saws breathed much better. there is a major size difference. Thats why I wanted the ht carb. i knew the new carb wasn't limited i just wanted the bigger one if it was gonna help.

With that said, how does an 066 make so much power with the tiny little carb they use. Compared to the 880 carb it is miniature.

I have an old ht7 laying around here and a new rebuild kit, but the plastic fuel elbow is cracked. I might try putting a longer hose on and running it without the elbow. I'm super busy at work and coming down with the flu or something so I haven't had a chance to mess with it lately but I will get this thing straightened out.

I did order the husky deflector and screen already so once that comes in i will jump back on it.

Thanks,

-AJ

 

[tacomatrd98]

yep mine has the hole,i could be way off here but my thinking is it probly reduces fuel pooling in the intake and would have to give some advance to intake timing

Thank you very much!

Did you open the mouth of the intake port to match the old style larger boot?

I was concerned that having that sharp "wall" at the bottom of the port would disrupt airflow and negate anything gained by the larger boot. From watching the videos of your saw I'm thinking it doesn't cause a problem though. Cant wait to get this thing back together and tuned in. :msp_biggrin:

 

[rb440]

Does anyone know part number of larger intake ?

 

[splitpost]

Does anyone know part number of larger intake ?

1124 141 2201 intake boot,you will also need the sleeve to suit 1124 141 1800

 

[bennn*e]

Funny this post should come up. Looking at a 880 for Christmas

 

[rb440]

I have early 2008 ms 880 with cast aluminum muffler and a poly flywheel, would this be a limited coil? If so what's the part number of 088 unlimited coil? Thanks

 

[splitpost]

I have early 2008 ms 880 with cast aluminum muffler and a poly flywheel, would this be a limited coil? If so what's the part number of 088 unlimited coil? Thanks

1124 400 1309

 

[rb440]

Nice! Thanks. Now to find one!

 

[Mastermind]

This coil 1124 400 1309, is it really an unlimited coil?

 

[Beer Gut]

This coil 1124 400 1309, is it really an unlimited coil?

I have one of the 441 coils. I had my 880 well into the 13000 with no rev limit. It's all the saw would do. And of course was way lean.

 

[rb440]

Not really sure I need unlimited coil. I'm gonna be pretty much stock but with pop up piston and muffler mod. What ya guys think?

 

[Mastermind]

I think popups are silly.

 

[rb440]

trust me I'd love to get it ported but unfortunately not an option right now.

 

[rb440]

Is the 441 coil a direct bolt on with no other modifications?

 

[Beer Gut]

Is the 441 coil a direct bolt on with no other modifications?

Not for your saw. You have the earlier model. I believe you need an 088 coil. Someone correct me if I'm wrong...

 

[blsnelling]

The 441 coil is the wrong coil for an earlier MS880 with the cast muffler. You need a 088 coil. It is a direct replacement and is not rev-limited. The 441 coil is rev limited and is only to be used on a later MS880 with a stainless steel muffler. The case is different on the later saw. The 088 coil that you need is PN 1124 400 1309.

 

[tyburn]

I did the 441 coil swap on my 880. It's a monster! Just eats up the 30" wide slabs I'm milling.
BUT, the timing is clearly farther advanced than normal. Starting it will rip off your fingers if you don't get over the hump on the first stroke.

I'm wondering if this could over-stress the cylinder hold-down bolts...I just blasted the screw heads off my 066 with a 56mm Hyway cylinder and high compression piston. I think OEM specs on that are lower vibration and better aligned with the rest of the saw's engineering...