splitpost
Nothing but 32:1
jeez i hope not ,maybe one of stihl techs can shed some light on this
New MS 880 Coil Swap
- Thread starter Beer Gut
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jeez i hope not ,maybe one of stihl techs can shed some light on this
It's not unheard of to close an H needle down like that. On some carbs, that doesn't shut off all fuel, it just closes the max amount that is adjustable. In other words, some of the fuel doesn't go past that needle. The only way to tell if you're too lean is to get it in wood. If it runs clean in the cut, and then 4 -strokes when you let off the load, you're fine. You do not have a limiter kicking in on the coil, as the coil is not jumping around. We need a vid of it in wood.
BTW, it looked like it was cold in the first vid. You don't want to rev out a cold saw. The piston expands faster than the cylinder, and can cause scuffing.
BTW, it looked like it was cold in the first vid. You don't want to rev out a cold saw. The piston expands faster than the cylinder, and can cause scuffing.
Beer Gut
A Fine Pilsner
Thankyou for the help I will try to get a vid in the wood today. And yes the 1st vid had a short warm up oops.
Just take great care to make sure it 4-strokes when you let off the load. You're experimenting, and I don't want to see you hurt your saw. I don't think you will, but just a warning. I'm glad to see there are some willing to explore new territory.
Beer Gut
A Fine Pilsner
Video is uploading now.
Beer Gut
A Fine Pilsner
[video=youtube;l1BzZ0lxlQs]http://www.youtube.com/watch?v=l1BzZ0lxlQs&feature=youtu.be[/video]
I warmed the saw for 3 or min and then attempted some test cuts the tune where it was left last night was far to lean the saw lost power in the cut and would bog down. It did sound to me to be 4 stroking but like I said the tune would not support the cut. I was able to run smooth with a tune of 11K on the head any leaner and saw would lose power in the cut. I made some more test cuts to warm it some more and recheck the tune then made the video. The saw is 4 stroking and has good throttle response but no higher than 11K RPM.
I warmed the saw for 3 or min and then attempted some test cuts the tune where it was left last night was far to lean the saw lost power in the cut and would bog down. It did sound to me to be 4 stroking but like I said the tune would not support the cut. I was able to run smooth with a tune of 11K on the head any leaner and saw would lose power in the cut. I made some more test cuts to warm it some more and recheck the tune then made the video. The saw is 4 stroking and has good throttle response but no higher than 11K RPM.
splitpost
Nothing but 32:1
Thats sounds alot better,the muff modd will deffinatly help
Beer Gut
A Fine Pilsner
Yes but now what? A steady 11K is better than stock with the rev limit because at those rpms the rev limit would kick in and throw the saw off. So the 441 coil was successful in fixing that issue and making tuning and muffler mod easier the saw runs and acts like a 460 or 660 now. So what would be the next step different carb, different jets, or port work?
Either way I would say its safe for you to put your new coil on and tune your saw to 11K. Unfortunatly until I get more direction the saw hasn't gain much more than 500 rpms, mine was taching out around a garbled 10500+ before the coil swap and now its a smooth ramp to 4 stroking 11000.
With the size of the mouth on this carb there is plenty of air coming in and now I would think the only way to gain more is to bring in more fuel and air equally (port work). But I'm hopeing that an aggressive dual port will allow more air flow and let me richen it up while still gaining some rpm.
By the way I pulled the muffler cover and looked at the P/C no damage from all this WOT. :msp_thumbsup:
You're definately not too lean in the cut. If anything, it's still quite rich. Will it tune to 12,000? I believe that's where the 084 and 088 were stock.
Where is your H needle now?
Beer Gut
A Fine Pilsner
A little less than 1 full turn off but more than 3/4. I know it sounds rich, but to me I can lean it all the way out and it still 4 strokes but then no power in the cut. I guess another video is in order, I will try my 3rd hand and see if I can tach it in the cut as well. Getting dark I'll see what I can do otherwise tomorrow.
Some of my dual port parts came in the rest should be here Monday, I should have it complete for next weekend.
That sounds like a rev limiter, be it ignition or carb. Don't take it any leaner than what will allow it to 4-stroke when you let off the load in the cut. Try 1/16-1/8 turn.
Beer Gut
A Fine Pilsner
How does a rev limiter in a carb work, what does it look like, can it be removed? Is it a govenor screw or a valve in the jets?
Mastermind
Work Saw Specialist
It looks like a brass screw on the side of the carb. Normally they have a sealer around them. To block it off I cut a piece of thin aluminum sheet to put in the hole then screw the valve back in.
Beer Gut
A Fine Pilsner
Okay thank you I will take a look in a little bit if I see something I will post a pic.
I'm pretty sure no rev limit in the coil or at least until the 13-14k range because the saw will rev out to 13300 like I posted in vid last night and no way no how with the old coil, it would simply fall apart climbing over 10500+.
timmcat
ArboristSite Operative
In the old days there was a little ball valve than started to dump fuel when the carb vibrated at a certain rate (rpm) Very common on old Tilly's, never seen one on a Walbro or Zama. As far as your adjustment question goes, the mixture screw only adds fuel to suppliment an internal fixed jet.
Beer Gut
A Fine Pilsner
Well no extra screws brass or steel. The only ones are holding it together or the 3 adjustment. :msp_sad:
Hey Beer Gut, I don't know if you have this info or if it will help but it may give you some interesting reading if nothing else.
Beer Gut
A Fine Pilsner
4.2 Ignition module
The previous ignition module 1124 400 1301 is being replaced by the version 1124 400 1302.
The new ignition module is distinguished by a microprocessor-controlled ignition system with ignition timing.
Advantages
– smooth starting – smooth idling – good acceleration – optimal performance – optimal torque
Interesting not that its noticable to my ear but I wonder if the microprocessor has the same timing for both saws and the 441 ignition timing is different and this coil is not performing correctly on this saw. It seems to run fine to me though.
It sounds like the rev limit is in the carb as well since adjustment room is small.
The previous carburetor HT-12E (1124 120 0609) remains available for older machines. The new carburetor WG-12 (1124 120 0611) can only be combined with the new cylinder with piston (1124 020 1209).
With this carburetor, corrections can be made at the high speed screw H and low speed screw L only within a narrow range. This helps to ensure that the full-load, partial-load and idle settings remain in a range that is good for the engine.
Thanks it is helpful and a good read. Interested to hear some others take on this read.
Beer Gut
A Fine Pilsner
After rereading again they only state limit in adjustment in the carb with the caps intact. With them out 1 1/2 turn on the H to set it then only 1/2 turn of adjustment with them back in. Mine are cut and I'm around 1 turn out on the H screw for a 11K tune which would be the leanest setting for a intact cap.. If I would go another half rich I would be right back where I started but seemed to rich to me.
