# Optimising an 090 for milling



## harrygrey382 (Jun 25, 2013)

I'll be using my 090 for milling soon and have a question or two. I want to make the most of the high torque and low speed. I'll run 404 chain because that's what my bar is. I'm thinking of an 8 pin regular or 9 maybe even 10pin racing sprocket. But does anyone know from experience how these stand up to milling?

Assuming I go with the 8 pin, what should I set the rakers at? Bearing in mind it'll be milling only aussie hardwoods - mostly yellow box (sometimes dead) but also stringy and sometimes forest red gum. It's only a 34" bar so 32" max cut if that at the moment. But I don't want to compromise surface finish for speed and have heard lower rakers does this...


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## mtngun (Jun 25, 2013)

Will Malloff milled with an 090 and wrote a book about it. Chainsaw Lumber Making

I've never run an 090, but do mill with a woods-ported 084, and have found a 7-pin 3/8 works best with it. 

Generally you want the saw to maintain revs without working too hard. If you lug it, it makes the engine run hotter.

I presume your 404 bar could easily be converted to 3/8 just by swapping the nose sprocket ?


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## flashhole (Jun 26, 2013)

opcorn:

Post some pics of the progress. I'm curious what all you will do to the saw.


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## 820wards (Jun 26, 2013)

harrygrey382 said:


> I'll be using my 090 for milling soon and have a question or two. I want to make the most of the high torque and low speed. I'll run 404 chain because that's what my bar is. I'm thinking of an 8 pin regular or 9 maybe even 10pin racing sprocket. But does anyone know from experience how these stand up to milling?
> 
> Assuming I go with the 8 pin, what should I set the rakers at? Bearing in mind it'll be milling only aussie hardwoods - mostly yellow box (sometimes dead) but also stringy and sometimes forest red gum. It's only a 34" bar so 32" max cut if that at the moment. But I don't want to compromise surface finish for speed and have heard lower rakers does this...



Harry,

I'm running a .404x8 sprocket on my 134cc PowerBee motor. It increased the chain speed by about 14% over the 7pin I started with. By using an 8pin sprocket you will be reducing the overall engine speed and since you are running an 090 saw you have the torque needed to use that 8 0r 9 pin sprocket. I have a 50" bar on my mill and only when I'm milling hardwoods over 40" using the 8pin sprocket do I need to use more throttle. I would suggest if you haven't already done so, use a nose oiler. Increasing chain speed also increases friction/heat which decreases bar/chain life. I would suggest leave your rakers set as they are now and give it a try, if you find that the saw is not laboring or bogging down you could lower them an additional .005". I have mine set at .042" since my motor has a lot of torque. Hope this helps.
jerry-


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## Uncle Rico (Jun 26, 2013)

mtngun said:


> Will Malloff milled with an 090 and wrote a book about it. Chainsaw Lumber Making
> 
> I've never run an 090, but do mill with a woods-ported 084, and have found a 7-pin 3/8 works best with it.
> 
> ...





Does anyone have a pdf of this book that they'd be willing to share?


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## flashhole (Jun 26, 2013)

I couldn't download it either. If someone has a .pdf I'll be second in line.


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## harrygrey382 (Jun 26, 2013)

mtngun said:


> Will Malloff milled with an 090 and wrote a book about it. Chainsaw Lumber Making
> 
> I've never run an 090, but do mill with a woods-ported 084, and have found a 7-pin 3/8 works best with it.
> 
> ...


I've been reading that, and it's pretty good. He doesn't talk about sprocket sizes, and just says he sets his rakers at .045 and makes no mention about surface quality. The 090 has a lot of talk and I know will have no problems holding revs with an 8 pin 404 in 32" of cut. But I was wondering if others have found this is enough chain speed or they could get more, and the effect of raker height on surface finish.


820wards said:


> Harry,
> 
> I'm running a .404x8 sprocket on my 134cc PowerBee motor. It increased the chain speed by about 14% over the 7pin I started with. By using an 8pin sprocket you will be reducing the overall engine speed and since you are running an 090 saw you have the torque needed to use that 8 0r 9 pin sprocket. I have a 50" bar on my mill and only when I'm milling hardwoods over 40" using the 8pin sprocket do I need to use more throttle. I would suggest if you haven't already done so, use a nose oiler. Increasing chain speed also increases friction/heat which decreases bar/chain life. I would suggest leave your rakers set as they are now and give it a try, if you find that the saw is not laboring or bogging down you could lower them an additional .005". I have mine set at .042" since my motor has a lot of torque. Hope this helps.
> jerry-


Thanks Gerry that's great. So I'll start out with an 8 pin sprocket, then drop the rakers incrementally keeping an eye on the finish. Do you know how many revs in the cut your motor is making? Do you know how a racing sprocket will hold up to milling? This is my second mill - the first one I made on your plans and was great, but didn't survive the move from UK to Australia. My new one is also using your plans. I've got a nose oiler for it but haven't used it yet - been using the 070 on it and the bar just wasn't getting hot. Might hook it up for the 090 though.

I'll try and upload this Malloff book to a file sharing sight - my satellite internet is real slow so emailing isn't an option. Will PM with a link


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## Greenland South (Jun 27, 2013)

Uncle Rico said:


> Does anyone have a pdf of this book that they'd be willing to share?



I can probably help you out with this. Not sure how to go about it though. I guess if you pm me I could send it to you?


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## Greenland South (Jun 27, 2013)

Uncle Rico said:


> Does anyone have a pdf of this book that they'd be willing to share?



This is where I found mine. Scribd
Hope this is allowed:msp_wub:


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## kimosawboy (Jun 27, 2013)

I just uploaded a copy for anyone, great book!!!
Cheers
G Vavra

Pogoplug: Chainsaw Lumbering


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## Big Beech (Jun 28, 2013)

harrygrey382 said:


> I'll be using my 090 for milling soon and have a question or two. I want to make the most of the high torque and low speed. I'll run 404 chain because that's what my bar is. I'm thinking of an 8 pin regular or 9 maybe even 10pin racing sprocket.



that's a little contradictory, I would of thought, given that a larger sprocket tooth set will increase chain speed, but decrease torque.
also I believe, the 090 standard is a seven tooth, well it is here in the UK at least, given you a very slow cut speed but masses of torque for the longer bar.
I am going to be using this setup soon with my mill on a 40" English Oak, so will post how I get on.

But, in my view forget the big sprockets otherwise you will end up with a wash board effect on your planks, and if the cutters and or rakers are not correct then vibration will cause havoc along the engine and crank.

good luck

simon


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## BobL (Jun 28, 2013)

Big Beech said:


> that's a little contradictory, I would of thought, given that a larger sprocket tooth set will increase chain speed, but decrease torque.


I don't think that is what he said. He just said that an 090 has lots of torque so it could handle a larger sprocket which would improve his chain speed, which is correct.



> But, in my view forget the big sprockets otherwise you will end up with a wash board effect on your planks, and if the cutters and or rakers are not correct then vibration will cause havoc along the engine and crank.



I think sprocket size is only one input to the causes of washboarding. I reckon is related to a synchronization between the chain speed, width of cut, raker depth and cutting speed. The only time I see it in Aussie hardwoods with the 880 is in narrow (<18") cuts. If anything, going to bigger sprockets will require rakers to be set higher which will make smaller chips so the chances of washboard are even less. 

The main problem I see with very large sprockets is whether the chain will still ride back onto the bar correctly after passing around the sprocket. The bars the racing boys use these sprockets with are usually modified to help them do this. A chain jumping the bar ay WOT at the start of the bar aint a pretty sight. I have a couple of 9/10/11 tooth sprockets I should drag out and mock up to see what they look like.


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## flashhole (Jun 28, 2013)

Matching the bar length to the diameter of the log helps a lot too.


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## harrygrey382 (Jun 29, 2013)

BobL said:


> I don't think that is what he said. He just said that an 090 has lots of torque so it could handle a larger sprocket which would improve his chain speed, which is correct.
> 
> 
> 
> ...


your first and third points are right on the money! I'm hoping the high(er) chain speed of the 8 pin will mean I don't have to lower the rakers too much, but I really want to know how far I can take them without bad surface finish. I haven't come across washboard yet... fortunately! Sounds like I don't want to either.

Simon - the standard 7 pin on an 090 is too small in most timbers today. I've actually got a blank splined clutch drum so there is no standard. But unless you're running a 50" plus bar I think a 7 pin is unsuitable for an 090. You'll be hitting the limiter the whole time or will need to drop the rakers a lot resulting in increased stresses on the chain. I'm sure it will mill 40" oak with an 8 pin no worries, it's not very hard timber really and 40" is small/medium on an 090 cf what it was designed for. Looking forward to your pics though, how about a video? Have you got an 090AV or fixed handle?


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## Big Beech (Jun 29, 2013)

harrygrey382 said:


> your first and third points are right on the money! I'm hoping the high(er) chain speed of the 8 pin will mean I don't have to lower the rakers too much, but I really want to know how far I can take them without bad surface finish. I haven't come across washboard yet... fortunately! Sounds like I don't want to either.
> 
> Simon - the standard 7 pin on an 090 is too small in most timbers today. I've actually got a blank splined clutch drum so there is no standard. But unless you're running a 50" plus bar I think a 7 pin is unsuitable for an 090. You'll be hitting the limiter the whole time or will need to drop the rakers a lot resulting in increased stresses on the chain. I'm sure it will mill 40" oak with an 8 pin no worries, it's not very hard timber really and 40" is small/medium on an 090 cf what it was designed for. Looking forward to your pics though, how about a video? Have you got an 090AV or fixed handle?



Hi Harry,

did not mean my response to come across perhaps as a noitall, dam internet!
at present I only have the option of a seven pin as I am still running the original spur sprocket. though another uk chap on another forum has just purchased a batch of drums and rims from your neck of the woods. when that arrives and is installed I will have more options as you do!
the saw is on its maiden tree cut on Monday on a 5ft Oak fell with a 48" duro sthil bar and was tached up this morning running 7.5 - 7.8K and cuts nice on the 30" bar and chain that it came with. so I am quite excited about using it proper since its been rebuilt. there are a few of my posts knocking around showing from start to finish on the chainsaw forum.
I have probably an early AV model as there is a STIHL emblem and an 090AV sticker on the top casing rather than name plates, which I would presume are later?
as for a video, yes hopefully if the rain holds of Monday, footage will be recorded for prosperity :smile2:
as for a 50"+ bar I would love one but really would not need a bar that big, even 48" is big by UK standards. anything over that is for gloating purposes but you never know, but not only that they are so expensive over here.

good luck and again any info I can learn re milling with the 90 much appreaciated :msp_thumbsup:

Simon


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## harrygrey382 (Jun 29, 2013)

Big Beech said:


> Hi Harry,
> 
> did not mean my response to come across perhaps as a noitall, dam internet!
> at present I only have the option of a seven pin as I am still running the original spur sprocket. though another uk chap on another forum has just purchased a batch of drums and rims from your neck of the woods. when that arrives and is installed I will have more options as you do!
> ...


No worries simon I reacted a bit too strongly anyway... I'm actually from west sussex, moved here a couple of years ago (well I'm dual citizen in fact). Where abouts are you? You do still see the odd tree I guess but people are normally a bit touchy about doing things like testing an 090 on them!
I lucked out a few years ago and bought a NOS oregon clutch drum for rims for 12 pounds. I didn't have an 090 at the time but thought it might come in handy later  I had a look at your 090 electrix thread, remember it from before actually but I had nothing to add after the experts chimed in. Not sure when they changed to name plates over castings, could it have been when they went to "type 2" AV?
That was a steal on the bar, 48" should be fine with an 8T in in 5' cut. Not sure about the 7.5-7.8k tuning though. Was it tuned via the extended edition manual? That is - disconnect governor, tune to 11k, reconnect governor, set to 8k. I'd say your 7.5-7.8 is good enough. But if you/they didn't disconnect the governor when tuning the actual mixture could be anything. Or if it was set at 7.5-7.8 without the governor it'll be insanely rich and you risk scoring/massive carbon build up.
I don't have a tach, I tune in the cut - timed cuts and in this saws case dogging the sh*t out of it to load it up. Then for milling I richen this by 1/8 - 1/4 of a turn. Looking forward to the video btw!


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## Big Beech (Jun 29, 2013)

Horsham is my home town. where were you based?

as for tuning, yes as you noted. but did not disconnect the vane, as I would of presumed that was untouched when it was running correctly. I would of hoped 

what should I do or change, just check plug colour? last thing I wanna do is bugger her up on Mondays big job!!!!


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## harrygrey382 (Jun 29, 2013)

Big Beech said:


> Horsham is my home town. where were you based?
> 
> as for tuning, yes as you noted. but did not disconnect the vane, as I would of presumed that was untouched when it was running correctly. I would of hoped
> 
> what should I do or change, just check plug colour? last thing I wanna do is bugger her up on Mondays big job!!!!



as I noted - as in tuned with a tach without touching the vane? If so then it's not tuned correctly at all. How much smoke does it put out at WOT? Checking the plug won't tell you a whole lot, unless yo use a new plug, make a few long cuts, then kill it while cutting, then have a look. 

The best would be tuning on the job with it in the cut. See what the H screw is set at now - if it's much different from 1 turn out and my first assumption is correct, reset to one turn out. Warm it up, if it idles and revs up well you can assume the L is correct. Make a cut - tuning while making the felling cuts might be a bit hairy though  If you've loaded it up well (this bit is probably the hard bit, you have to decide what makes an 090 load up) and it is not four stroking, richin it until it does. Then lean it until it just doesn't four stroke in the cut. Might be best to either disconnect the vane or stiffen the spring right up so you're not confusing the governing with four stroking. 

If all else fails and you're just felling and making a few cross cuts, 1 turn out will probably be ok. But if milling you want to get it just right, then richen a little bit.

I grew up between midhurst and petersfield, my family are still there. Still love the place but I need the space and wildness of this place


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## Big Beech (Jun 30, 2013)

When it first came to life we tuned to the fourstokibg sound as best we could.
Thsn when tried in wood if just bogged out woulndt hold revs n died. Was a bastard to restart. So went bak to basix 1 turn on eacch n got it runninv again.
When i tunex it on saturday initial readinv was 5.8k. Turnd h until revs lifted.on tic over a little smoky. Backex tbe L back idle rose turned that bac tik over now at 1.8k.checked on tach to the current 7.5k. No smoke on idle snappy pikup too.
Ran it in log along the grajn. Pullslike a train and held revz niceley whilst doggin in too!
Currently living in Bedham near petworth.

Cheeds S


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## harrygrey382 (Jun 30, 2013)

Big Beech said:


> When it first came to life we tuned to the fourstokibg sound as best we could.
> Thsn when tried in wood if just bogged out woulndt hold revs n died. Was a bastard to restart. So went bak to basix 1 turn on eacch n got it runninv again.
> When i tunex it on saturday initial readinv was 5.8k. Turnd h until revs lifted.on tic over a little smoky. Backex tbe L back idle rose turned that bac tik over now at 1.8k.checked on tach to the current 7.5k. No smoke on idle snappy pikup too.
> Ran it in log along the grajn. Pullslike a train and held revz niceley whilst doggin in too!
> ...


Not sure what's up with your phone Simon but its quite hard to make out what you meant! Or are you on the piss? Either way, kind sounds like everything is good if it's got heaps of grunt and doesn't smoke. I'm still not totally sure if you tuned it with the vane disconnected though? You can't tune with a tach and not disconnect the vane...


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## Big Beech (Jun 30, 2013)

Ha, yeh if only!! was a late night but an early morning get up over to east Sussex to see the good ladies grandparents on the farm. so, sorry for the phone tap talk crap.
but basically, I did not move the vane to max out at 11k. I will see how we go tomorrow morn first and then may do a redo tach n tune on site. but the thought of taking the dam starter box on and off will be a pain no doubt. we will see :msp_smile:
hopefully will get the video on the go to.

thanks for your help Harry and sorry to derail your initial thread 
 simon


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## mtngun (Jul 1, 2013)

harrygrey382 said:


> I'm hoping the high(er) chain speed of the 8 pin will mean I don't have to lower the rakers too much


 Why ? What is so important about surface finish ? 

If the board is to be planed, then surface finish won't matter. Surface finish won't even effect how much has to be planed since there is usually more variation in thickness for other reasons when using an Alaskan mill. 

If the board is to be used a rough lumber, then once again surface finish won't matter.



> You'll be hitting the limiter the whole time or will need to drop the rakers a lot resulting in increased stresses on the chain.


Huh ? I've never broken a 3/8 chain while milling, and my milling saws never run at max rpm. 

The OP seems to assume that an 090 has a surplus of power. Wrong ! :msp_thumbdn: There is no such thing as a surplus of power for milling. If your powerhead is not working hard while milling, then your chain is not sharpened correctly. 

The OP assumes that there is something wrong with aggressive rakers. Wrong ! Aggressive rakers are a good thing for milling.


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## harrygrey382 (Jul 1, 2013)

mtngun said:


> Why ? What is so important about surface finish ?
> 
> If the board is to be planed, then surface finish won't matter. Surface finish won't even effect how much has to be planed since there is usually more variation in thickness for other reasons when using an Alaskan mill.


think I'll have to contend this. I haven't fully decided how I'll be finishing, but at least some will be for a dining table. So I'm wanting full width slabs. I doubt I'll be able to find a planer or thicknesser around here that will take these widths so may be doing it by hand, not sure yet. Either way, assuming I mill them flat, consistently and dry them properly (I know all big assumptions) the better the surface finish the less work later. I disagree about there being necessarily more variations for other reasons. True sometimes other things go wrong, but not always. If everything goes right (and I've had plenty of boards where it has) all that needs cleaning up are the saw marks. 

so, if raker height does affect surface finish like a lot of experienced millers say it does - I'm interested. I'm not saying there is anything wrong with aggressive ones, I've just read several times they make the finish rougher. It would have been ideal (too good to be true maybe?) if someone had made a grading of raker height vs surface finish in a given situation!



mtngun said:


> The OP seems to assume that an 090 has a surplus of power. Wrong ! There is no such thing as a surplus of power for milling. If your powerhead is not working hard while milling, then your chain is not sharpened correctly.


I wasn't assuming this. I was assuming the 090 revs lower and has more torque than say an 880 or 660 (fair assumption, eh?). And I was asking how people who have used one for milling make the most of this situation seeing as chains and sprockets these days are designed for higher revving less torquey saws that are the norm


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## mtngun (Jul 1, 2013)

harrygrey382 said:


> some will be for a dining table. So I'm wanting full width slabs. I doubt I'll be able to find a planer or thicknesser around here that will take these widths so may be doing it by hand


Why not use a router sled ? 



> if raker height does affect surface finish like a lot of experienced millers say it does - I'm interested. I'm not saying there is anything wrong with aggressive ones, I've just read several times they make the finish rougher. It would have been ideal (too good to be true maybe?) if someone had made a grading of raker height vs surface finish in a given situation!


When running VERY aggressive rakers (8 - 9 degree angle) and the Malloff grind, I typically see washboarding on the first pass, sometimes on the 2nd pass, but then smooth cuts on subsequent passes, as the cutters gradually lose their sharpness and take smaller bites. So it's not just a question of rakers, but also sharpness and cutter angle.

Aggressive rakers allow the saw to cut freely, without pushing hard on the mill. Typically people who run standard rakers will rock the saw from side to side to try to get the chain to bite. 

I commonly see 1/8" thickness variations on boards (from one spot to another) due to the Alaskan mill, regardless of surface finish. The Alaskan mill and the guide board are not perfectly rigid, things flex and wobble, and the bar flexes, so you get some variation. Then when the board dries it often cups a bit. If I'm going to plane a board, I usually take off at least 3/16", regardless of surface finish.



> I was assuming the 090 revs lower and has more torque than say an 880 or 660 (fair assumption, eh?). And I was asking how people who have used one for milling make the most of this situation seeing as chains and sprockets these days are designed for higher revving less torquey saws that are the norm


Most of what we know about milling chains comes from Will Malloff, who used a 090. The Malloff chain grind also works well on high revving saws. It cuts rougher, too. Malloff aimed for speed, not surface finish.

Generally, anything that makes the chain take a bigger bite -- raker angle, cutter angle, cutter sharpness -- will produce a rougher finish, but cut faster. Anything that takes a smaller bite will produce a smoother finish, but cut slower.


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## BobL (Jul 1, 2013)

mtngun said:


> When running VERY aggressive rakers (8 - 9 degree angle) and the Malloff grind, I typically see washboarding on the first pass, sometimes on the 2nd pass, but then smooth cuts on subsequent passes, as the cutters gradually lose their sharpness and take smaller bites. So it's not just a question of rakers, but also sharpness and cutter angle.



I think the reason washboarding happens more likely on the first (and also last) few passes on a log is the cuts are narrower and wood is slightly softer so the cuts can be made at a speed that enables the chain speed to synch with the cutting speed. If it happened just due to chain sharpness then I would see it every time I touched up or swapped to a fresh chain.

This is my go to picture about this.
Same saw, same wood, equally sharp chain, the only difference is the right hand cut is 30%^ wider than the left.
BTW rakers are only at 6.5º on these cuts.


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## 820wards (Jul 5, 2013)

harrygrey382 said:


> I've been reading that, and it's pretty good. He doesn't talk about sprocket sizes, and just says he sets his rakers at .045 and makes no mention about surface quality. The 090 has a lot of talk and I know will have no problems holding revs with an 8 pin 404 in 32" of cut. But I was wondering if others have found this is enough chain speed or they could get more, and the effect of raker height on surface finish.





> Thanks Gerry that's great. So I'll start out with an 8 pin sprocket, then drop the rakers incrementally keeping an eye on the finish. Do you know how many revs in the cut your motor is making?



A stock 820 PowerBee motor operating RPM range with a 3/4" intake with a stock exhaust is around 7600rpm if I remember correctly give or take a 100rpm. I have installed a 1" bore intake/carb, carbon fiber reed valves and a 2" exhaust. Without putting a tach. on the motor I think I'm easily in the 8,500rpm range WOT. With .042" rakers I still have gotten smooth cuts even with the black Oak I have milled. 




> Do you know how a racing sprocket will hold up to milling? This is my second mill - the first one I made on your plans and was great, but didn't survive the move from UK to Australia. My new one is also using your plans. I've got a nose oiler for it but haven't used it yet - been using the 070 on it and the bar just wasn't getting hot. Might hook it up for the 090 though.



I think your 090 will do quite well with an 8pin sprocket since you have the torque of a large motor. I usually run my mill, a .134cc motor at 3/4 throttle when milling. I have also welded in an additional baffle on my fan-recoil shroud that forces additional air over the cylinder head to keep the engine temp good over longer milling cuts, so I've never had excessive heating problems even in warm-hot weather. Your 090 is a great motor, take care of it and it will provide may hours of milling service.

Cool to hear you tried my mill design, good luck on your next build. Post us some photos if you can of your build.

jerry-


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## splitpost (Jul 15, 2013)

bump


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## harrygrey382 (Jul 16, 2013)

yeah hanging out to get milling but it's not going to happen for a couple of weeks... Liking the 8pin 404 for bucking though


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## 820wards (Jul 16, 2013)

harrygrey382 said:


> yeah hanging out to get milling but it's not going to happen for a couple of weeks... Liking the 8pin 404 for bucking though



With a shorter bar for bucking and an 8pin sprocket, your 090 should tear through firewood. Have fun! I have three logs to mill myself, but it's been too hot here to mill and I don't want the wood to be checking on the ends.

jerry-


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## WidowMaker1 (Jul 24, 2013)

generally always running 8 tooth .404 on my 090, does it all with ease


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