Killed the MS880 while milling

[billstuewe]

BobL, Where did you get your temp guage? What kind? and How much$?

Thanks,
Bill

 

[BobL]

BobL, Where did you get your temp guage? What kind? and How much$?

Thanks,
Bill

It's from a company that supplies parts for RC vehicles.
www.traxxas.com/products/nitro/jato/trx_jato_accessories.htm

 

[Kicker_92]

I've got the new piston now, and have a tach borrowed to help tune with.

So on a coil limited saw, how do you tune the fuel mixture? I've tried searching but haven't found much. The 880 I believe it limited around 11,000 rpm?

 

[mtngun]

I've got the new piston now, and have a tach borrowed to help tune with.

So on a coil limited saw, how do you tune the fuel mixture? I've tried searching but haven't found much. The 880 I believe it limited around 11,000 rpm?

Good on you for scrounging a tach.

You'll have to verify the factory spec for WOT. Lean the H until it hits the limiter. When it hits the limiter, your tach will go crazy and give erratic readings. Then richen the H until the tach starts behaving again, and the revs are at least 500 rpm below the limit.

Traditionalists will insist that you get an unlimited coil and tune by ear, but Lakeside was comfortable tuning a limited saw with a tach. Lakeside also recommended tuning a miling saw to less than the factory rpm spec.

You are going to have the cylinder replated, right ? Let us know how that works out.

 

[BobL]

Good on you for scrounging a tach.

You'll have to verify the factory spec for WOT. Lean the H until it hits the limiter. When it hits the limiter, your tach will go crazy and give erratic readings. Then richen the H until the tach starts behaving again, and the revs are at least 500 rpm below the limit.

That's basically what I do.

The coil is limited to 12,000 rpm so you are safe on 11,500.

I have a muffler mod on mine so it really wants to run above that but I set it on 11750 which is a couple of hundred revs above the 4 stroke burble.

I find sitting on around 9500 in the cut gives me a good compromise between cutting speed, raker depth and temperature.

 

[Kicker_92]

It's Alive!

Fired up the saw this evening. Had a bit of trouble as I decked a bit too much off the cylinder (it slipped in the clamp while milling). Ended up at 0.013" squish.

Not a big deal, cut a new base gasket to bump that back up to 0.025". Pulled easy for the first couple pulls, then burped. Next pull with choke off fired right up. Don't have a gauge to check compression with, but it'll take a strong shoulder even with the de-comp!

Didn't have a bar & chain on it at home, so will have to hold off on tuning until Sunday. Definately sounds a lot more mean than it used to, a lot more 'pop' in the exhaust note.

I'll set the mixture to 11,500 the see how it does in the cut. Still have to make a new plate and pipe for the exhuast too.


JUst want to thank everyone for the tips and help. Looking forward to getting it back on the mill next week and making some sawdust!

 

[mtngun]

Glad it is running again. I hope you tested it for leaks ?

 

[robertjinnes]

Not acid---lye

Acid will eat most metals. Lye (DRANO) will eat aluminum faster than anything else --Look at the crystals, there are chunks of aluminum mixed in. Lye eats aluminum and creates heat---TADA unplugged drain. When using LYE or acid, use caution both for you and for the cylinder. Don't dump lye in a bucket and submerge the jug. You'll actually eat the threads out everything, including the spark plug hole. Place a couple dozen granules into the cylinder near the worst aluminum build up, dribble water on them and mush the mix around on the aluminum. Dump and rinse after 30 seconds to a minute. Repeat as and where needed. Just cleaned up a Huski 3120 jug that had burned a large portion of upper ring land and then chewed up 1/3 of the top piston ring. Thanks to Nikasil, After lye and about 2 minutes with a fine long stone cylinder hone, I was left with one scratch where a piece of ring had left a minor scratch from the top of the cylinder and down the cylinder wall approx 3/8 inch with the worst above where the ring will ever hit--- $40 plus shipping for a new piston, $13 for bearings and $19 plus shipping for a complete gasket set including crank seals. That $72 changed a $200 parts saw back into a $1000 monster for my Alaskan Mill.
Good Luck
Bob the Treeman

 

[Oden]

Cylinder?

Kicker
What did you end up doing with your cylinder? if replated how much did that cost?

thanks
Oden

 

[Kicker_92]

What did you end up doing with your cylinder? if replated how much did that cost?

We descided to re-use the cylinder. With the age of the saw, and the high cost of a replacement cylinder, it just wasn't worth putting more money into.

And I really couldn't do some major port work on a new or re-plated cylinder. Got the muffler opened up to around 3/4" (19mm), should hopfully get a chance tomorrow night to test and tune it. It sounds downright angry now, looking forward to throwing some chips.

Maybe a 9-pin will be an option now?

 

[Kicker_92]

The coil is limited to 12,000 rpm so you are safe on 11,500.

Bob,

How old is your 880? I put the tach on mine tonight, and the coil seems to cut out exactly at 10,500 rpm.

It four strokes right up to that point, so I tuned it in the cut to run about 9,000 rpm. Burbles as soon as you let the pressure off the mill, but runs nice in the cut. Only had a 20" wide cut setup to work with so not a great test, but very happy with the extra grunt it's picked up!

I'll have to get it into some 40" wood and see how she does.

 

[BobL]

Bob,

How old is your 880? I put the tach on mine tonight, and the coil seems to cut out exactly at 10,500 rpm.

Mine is a 2008 model.

It four strokes right up to that point

That sounds like your H screw is set too rich, have you leaned it out as per manual?

 

[huskyhank]

snipped.....

Burbles as soon as you let the pressure off the mill, but runs nice in the cut.

What BobL wrote and--

Run it like this for a cut, shut it off, pull the plug and look at it. If the plug is black and oily you might lean it out and re-check. If its just real dark brown I'd leave it alone. But you're not far off - if its running good in the cut it may be just fine as is, especially while you're breaking in the new parts. Don't go too far lean or you'll be re-building it again.

 

[Kicker_92]

That sounds like your H screw is set too rich, have you leaned it out as per manual?

I'm thinking they might have slightly differant limiters since mine would be a bit older than that. (2006?) 10,500 is fine, it won't hit that in the cut, but might keep an eye out for an unlimited coil for easier tuning.

I'm sure it's set too rich, but it does smooth out once theres some extra resistance. Chain is sharp and rakers are set at 8°, and it's still asking for more in a 20" wide cut.

We'll be keeping it on the rich side for milling, can't afford to melt any more parts. It's definatly running a lot cooler with the exhaust mods.

 

[mtngun]

I'm sure it's set too rich, but it does smooth out once theres some extra resistance. Chain is sharp and rakers are set at 8°, and it's still asking for more in a 20" wide cut.

That's the nice thing about using an 880 -- it's just loafing along instead of straining like a 90cc saw.

 

[Haywire Haywood]

rakers are set at 8°.

I don't quite understand what you mean here.. Rakers are usually set in thousandths (below tooth level). I usually use a .030 guide on my firewood chain.

Ian

 

[mtngun]

I don't quite understand what you mean here.. Rakers are usually set in thousandths (below tooth level). I usually use a .030 guide on my firewood chain.

Ian, members of the elite AS milling forum take chain sharpening to a whole new level, using a digital protractor to set rakers. This is a spin-off of the File-o-plate method which attempts to maintain rakers at a more-or-less constant angle relative to the cutter.

 

[MR4WD]

I'm thinking they might have slightly differant limiters since mine would be a bit older than that. (2006?) 10,500 is fine, it won't hit that in the cut, but might keep an eye out for an unlimited coil for easier tuning.

I'm sure it's set too rich, but it does smooth out once theres some extra resistance. Chain is sharp and rakers are set at 8°, and it's still asking for more in a 20" wide cut.

We'll be keeping it on the rich side for milling, can't afford to melt any more parts. It's definatly running a lot cooler with the exhaust mods.

Talk to tree sling'r, he'll set you up with an unlimited coil. What are you using to set your rakers? Best I could come up with was your typical analog angle finder. It's pretty big and cumbersome. I should get BobL to send me one like his! Do you have any pics of your muffler mod?

 

[BobL]

Talk to tree sling'r, he'll set you up with an unlimited coil. What are you using to set your rakers? Best I could come up with was your typical analog angle finder. It's pretty big and cumbersome. I should get BobL to send me one like his! Do you have any pics of your muffler mod?

Digital Angle Finders (DAF) are much cheaper in the US than I can get them for here. see http://www.wixey.com/anglegauge/index.html

I also have one of the cheaper ($19.95) ones, but it chews thru batteries much faster than the more expensive ones, they also have problematic zero switches.

If you don't want to go to the bother of using a DAF then an FOP type gauge is superior to a fixed depth gauge especially as a cutter wears.

 

[Kicker_92]

I use the same Wixey gauge as Bob, we actually have them here at work for measuring angles on parts.

I think it'd be around equivalent to 0.040" raker depth on a new chain at 8°.