Clutch cover mods

[Rockfarmer]

Just read Will Maloff's book and am wondering how many guys alter their clutch covers. It seems like a good idea but may be dangerous. If the chain lets go or jumps the bar it usually piles up in the cover. Now if this cover is almost all removed where that chain going when this happens? Does anyone have any good advice on this. Has anyone fabb'd up their own cover. I'd like to weld one up myself instead of wrecking the cover I have. I also would like to include obviously a chain catcher. Any thoughts there? Thanks, RF

 

[slabmaster]

I would think you are pretty safe in a mill as it would stop the chain real fast.I have thought of modding one with a guard around the clutch so the shaving don't pile up but haven't yet. I do blow everything uot real good at the end of the day and have not had any problems from sawdust in that area when milling.I do let the saw run in the upright position to clear the guard between boards and to let the saw cool down before shutting off.

 

[BobL]

Here's mine.

As you can see by the way the mill bolts to the bar bolts I had to remove mine completely. I have bought another Stihl cover and was going to modify that but I ended up making this temporary cover and it works so well it is still there.

I would remove the cover completely but then the sawdust would pile up around the exhaust. I mill mostly hard to very hard wood so my rate of sawdust production is not a large as softwoods.

 

[Rockfarmer]

Very nice!! Is that plexiglass over the front of the cover, thats fancy! What size saw is that? Does that have the metal screen type air filter and are there any mods that can be done to the filter to give it more surface area? Thanks RF

 

[BobL]

Very nice!!

Thanks

Is that plexiglass over the front of the cover, thats fancy!

Yep - its polycarbonate, tough stuff.

What size saw is that?

Its an 076AV, 111cc - follow the BIL mill link in my signature to see more.

Does that have the metal screen type air filter and are there any mods that can be done to the filter to give it more surface area? Thanks RF

Unless you really know what you are doing I wouldn't mess with providing more air, you actually want slightly less air - relative to the amount of fuel - when milling. The filter does get dirty quickly though and depending on the type of logs it needs to be cleaned regularly.

 

[BlueRider]

Unless you really know what you are doing I wouldn't mess with providing more air, you actually want slightly less air - relative to the amount of fuel - when milling. The filter does get dirty quickly though and depending on the type of logs it needs to be cleaned regularly.

I picked up a wasted TS760 to use for parts. Among the usable parts were the air cleaner cover,baseplate and mounting screws. I havn't measured the surface area or the TS 760 vs the 075 but the TS 760 uses a round canister style filter that looks significanrly biger. There are 2 diferent filter options and one has a rmovable outer pre filter.

I have all the parts mounted on my 075 and it is not running right now. I have not tried them on my 051. They should fit. The 075 uses a diferent carb riser block that is taller and has a wider bolt spacing on the cylinder side and the same spacing on the carb side. so the switch to a 051 might need some other mods height wise.

 

[BlueRider]

I forgot to add that a stock 075 and 051 both use the same air filter. there are 2 direrent chioces from Stihl and their designation always confuses me. they call one a flocked and the other something else. one is the old style metal mesh with a fiber flocking and the other is a yellow paper like fiber and is the easiest to find. I find the paper type to be easier to clean and slightly more durable.

Sorry for the thread hijak. I too thought the clutch mod was interesting. I have never had problems with clutch wear or even cloging though it gets pretty jamed by the end of the day. I have noticed that the acumulated sawdust can get burnished and packed pretty hard and the mod might be worth thinking about if for no other reason that the saw may run slightly cooler due to a bit less friction. this is a bit off set by a bit less thermal mass and surface area to help disipate the heat. what say the resident physicist?

 

[Texas Traveler]

I forgot to add that a stock 075 and 051 both use the same air filter. there are 2 direrent chioces from Stihl and their designation always confuses me. they call one a flocked and the other something else. one is the old style metal mesh with a fiber flocking and the other is a yellow paper like fiber and is the easiest to find. I find the paper type to be easier to clean and slightly more durable.

Sorry for the thread hijak. I too thought the clutch mod was interesting. I have never had problems with clutch wear or even cloging though it gets pretty jamed by the end of the day. I have noticed that the acumulated sawdust can get burnished and packed pretty hard and the mod might be worth thinking about if for no other reason that the saw may run slightly cooler due to a bit less friction. this is a bit off set by a bit less thermal mass and surface area to help disipate the heat. what say the resident physicist?

I think the TS510 or the 570 quick saw use a oversize air filtor that may work better. They are made in Brazil.

 

[Brownpot Deaton]

awesome ccover..they should make those standard...would be sooo sweeet.

 

[BobL]

I forgot to add that a stock 075 and 051 both use the same air filter. there are 2 direrent chioces from Stihl and their designation always confuses me. they call one a flocked and the other something else. one is the old style metal mesh with a fiber flocking and the other is a yellow paper like fiber and is the easiest to find. I find the paper type to be easier to clean and slightly more durable.

That's interesting because the 076 has a flocked plastic mesh that's quite difficult to clean. Depending on what I'm cutting I find I have to take it out and tap the excess dust off every 3 or 4 slabs and sometimes, on hard dusty Aussie hardwood, after every second slab. At the end of the day I usually wash it with Simple Green detergent. I have access to some very good air filter materials but am reluctant to modify the filter because I do not trust my ability to retune/rejet the carby to suit the filter. While we could all use a little more power I'm reasonably happy with the milling speed of the 076 on most of the logs I mill. The greatest variable for me seems to be getting the chain sharpening "just so".

Sorry for the thread hijak. I too thought the clutch mod was interesting. I have never had problems with clutch wear or even cloging though it gets pretty jamed by the end of the day. I have noticed that the acumulated sawdust can get burnished and packed pretty hard and the mod might be worth thinking about if for no other reason that the saw may run slightly cooler due to a bit less friction. this is a bit off set by a bit less thermal mass and surface area to help disipate the heat. what say the resident physicist?

I think that we generally under estimate the value of air flow around saws, bars and chain. That's why I think some excess bar hanging out of the side of the mill helps up to a point cool a chain/bar more than the extra friction the additional length that the bar/chain friction adds. I have no proof for this but I hope to get access to an infra red camera to test this. In terms of the clutch cover, sawdust is a very good insulator and there is no doubt that packing it around a sprocket will make it run hotter than necessary, so any mechanism that gets rid of it will reduce heat. Leaving the clutch cover on with packed sawdust around inside wouldn't help the metal clutch cover lose heat even if it was finned and fan assisted.

Another reason I like to leave some form of clutch cover on is that while milling I sometimes lean on the saw with my left knee/leg. This means I'm leaning on the wrap handle/top of clutch cover. If the cover was not there my leg would be getting too close to the chain and sproket! That's also why I still wear chaps while milling.

 

[BlueRider]

Another reason I like to leave some form of clutch cover on is that while milling I sometimes lean on the saw with my left knee/leg. This means I'm leaning on the wrap handle/top of clutch cover. If the cover was not there my leg would be getting too close to the chain and sproket! That's also why I still wear chaps while milling.

Excelent excelent point. I have an extra clutch cover and will have to look at modding it with an eye towad retaining the safty aspect yet also trying to get rid of a bit of the sawdust.

The TS 760 uses a similar canister as the current 500 series saws. The inside filter is a plastic mesh filter that is 1.75" in diameter and 1.5" tall and an outer pleated paper filter thats 3.75" in diameter and 2.25" tall.

With all this talk of air filters mixed in with the clutch cover discussion I have to also wonder if moding the clutch cover on a 051/075 might lead to throwing more sawdust up into the air filter. On the 090 the airfilter is configured different due to the intake and exhaust ports being on opposing sides of the cylinder similar to the new style of Stihl saws.

My idea is to retain all the clutch cover and cut out a round hole over the clutch that is the same size of the clutch. If you look at the stock cover there is a wall in the casting the fits around the clutch. I would basicaly cut to this wall and leave it intact. I think this would prevent sawdust and head from building up around the clutch but the sawdust would still flow pretty much as it does now.

 

[busybeazz]

i took my clutch cover off and welded 2 finder spacers off of a chevy truck and used my existing bar nuts works real well no problems i can even tighten up my bar with out removing nuts and washer.

 

[BobL]

With all this talk of air filters mixed in with the clutch cover discussion I have to also wonder if moding the clutch cover on a 051/075 might lead to throwing more sawdust up into the air filter. On the 090 the airfilter is configured different due to the intake and exhaust ports being on opposing sides of the cylinder similar to the new style of Stihl saws.

I find the amount of dust on the filter depends on the type of wood I'm cutting and the direction of the wind

My idea is to retain all the clutch cover and cut out a round hole over the clutch that is the same size of the clutch. If you look at the stock cover there is a wall in the casting the fits around the clutch. I would basicaly cut to this wall and leave it intact. I think this would prevent sawdust and head from building up around the clutch but the sawdust would still flow pretty much as it does now.

I looked at that idea as well, I even bough a brand new clutch cover so that I could mod the old one in the way you describe but I don't think it will help much or at all. The sawdust is flung away from the clutch/sprocket and pack up around the inside of the cover. The best thing to do is open up the whole thing as much as possible. The next version of my cover will look similar to what I already have but I will drop the transparent cover.