Clutch abuse

[Old2stroke]

I have seen this happen to too many saws operated by novice owners, I will use my friend's case to show what I am talking about. He acquired a nice Homelite 47 and started using it without knowing anything about chainsaws or even having read anything about how to use them. Of course the chain quickly became dull and to make it keep cutting, he just kept putting more pressure on the bar, so much pressure that he was dragging the rpm down to the point where the clutch was slipping and often stalling the chain. The clutch got so hot it blistered the clutch cover and melted the chainbrake band into the plastic. No, he did not have the brake on, didn't know what it was for or how to use it. The needle bearing of the clutch had a plastic cage and the cage melted and stuck the clutch drum to the crankshaft. The smoke coming out of the saw didn't bother him too much, it's a 2-stroke engine and they all make smoke, right? The clutch now engages at such a low rpm that it's difficult to achieve a good idle. The clutch is a good three piece steel shoe unit with a wrap-around spring, is it possible that it got so hot, it softened the spring? This is the most extreme case of course, but I have seen a lot of blistered clutch covers.

 

[s sidewall]

Clutch spring defiantly shot, get him a hand saw. Let him learn on that.

Steve, Samsung On5 using Tapatalk

 

[Sleepy]

Sounds like he is severely lacking common sense, the kind of guy that gives chainsaws a bad reputation.

 

[Woos31]

Sounds like he is severely lacking common sense, the kind of guy that gives chainsaws a bad reputation.

And fills up statistic graphs

 

[Sleepy]

And fills up statistic graphs

And of course it's always the chainsaws fault, because they're dangerous.

 

[s sidewall]

Owner's manual, what's that?

Steve, Samsung On5 using Tapatalk

 

[dswensen]

And fills up statistic graphs

Well, it does bode well for cleaning out the gene pool a bit.

 

[s sidewall]

This is for you Old2stroke, figured it would go good with your avatar pic. Those aren't fun to work on.

Steve, Samsung On5 using Tapatalk

 

[Big_Wood]

Well, it does bode well for cleaning out the gene pool a bit.

sadly, even with all other things; it ain't cleaning the gene pool quick enough. we have several generations of stupid bred together at this point and it's spreading way to fast to stop it now. the worst is that stupid people don't plan having children nor care if they can afford it cause they know the government will pull from others wallets to support them anyways. this results in stupid people being the majority of people breeding and raising children to be just like them (scary). couple generations of that and what do you have?.....................kids these days lol i'm over it, the world is doomed anyways so i'll be happy if people just leave me alone and stay out of my way lol.

 

[Woos31]

Well, it does bode well for cleaning out the gene pool a bit.

Very true

 

[jmssaws]

Seeing someone pry on a dull saw,run one that's not even close to being tuned or a wfo cold start makes me yell at them and sometimes it's hard to refrain from doing them bodily harm.

Work on them every day and see some of the stupid things people do and you loose all sympathy for them.

 

[Larry Leveen]

I have seen this happen to too many saws operated by novice owners, I will use my friend's case to show what I am talking about. He acquired a nice Homelite 47 and started using it without knowing anything about chainsaws or even having read anything about how to use them. Of course the chain quickly became dull and to make it keep cutting, he just kept putting more pressure on the bar, so much pressure that he was dragging the rpm down to the point where the clutch was slipping and often stalling the chain. The clutch got so hot it blistered the clutch cover and melted the chainbrake band into the plastic. No, he did not have the brake on, didn't know what it was for or how to use it. The needle bearing of the clutch had a plastic cage and the cage melted and stuck the clutch drum to the crankshaft. The smoke coming out of the saw didn't bother him too much, it's a 2-stroke engine and they all make smoke, right? The clutch now engages at such a low rpm that it's difficult to achieve a good idle. The clutch is a good three piece steel shoe unit with a wrap-around spring, is it possible that it got so hot, it softened the spring? This is the most extreme case of course, but I have seen a lot of blistered clutch covers.

Hah, sounds like what has happened to a saw I have -- I didn't do it, I swear! I'm just trying to diagnose and fix it. Mine is a Craftsman 358351702, and the pix I have seen of replacement drums seem to show the caged roller bearings stuck in there, so maybe they are pressed in at the factory and the one you mention (and mine) are not melted. But regardless, if the rollers are damaged, perhaps they will transfer torque to the drum (even w/o the clutch contacting the drum) and cause chain creep during idle. What do you think?

It's a mystery whether the saw was revved when it got stuck or if it got revved with the chain brake on. Wouldn't they both cause clutch slip and enough friction-heating to blue/discolor the clutch & drum and melt the chassis plastic?

In the case of my saw, that melted plastic caused the brake band to sit non-concentrically until I built up the "seats" it rests on so that it is again centered (when off) and doesn't contact the rotating drum. But I still have chain creep during idle, despite adjusting the idle screw out. I need a spline tool to adjust the L & H screws and have been reading up on those adjustments. It is clear to me that those need to be done properly for safety and longevity of the engine. Any thoughts about that (chain idle)? Is there a condition under which the carb needs to be cleaned/replaced that could cause high idle/chain creep?

 

[Old2stroke]

The clutch bearings in the saw I was working on were definitely in a plastic cage and it was definitely melted. The bearing in a steel cage is often a press fit in the clutch drum. If the drum is free to spin on the crankshaft, then it cannot be the cause of chain creep at idle. Probably the clutch got so hot it softened the spring holding the shoes in and the clutch now engages at a much lower rpm. Is the idle higher than it should be and are you saying that you can't lower the idle speed by backing out the idle speed screw? If the low speed mixture screw is set too lean, it could be part of the problem causing high idle. Try backing it out 1/4 turn. Without the special tool, I usually cut a slot in the head of the screw with a thin cutting wheel in a dremel tool and then use a regular screwdriver. If you can lower the idle rpm and the chain still creeps, you probably need a new clutch spring but chainsaw parts suppliers will want to sell you a whole clutch assembly. If you take the spring off and measure the length, the diameter of the coil and the diameter of the wire that the coils are made, you could search your local hardware stores and if you find a spring that matches those 3 dimensions, it will work. Trying to rev up a saw with the chain brake on would have the same overheating effect, but usually the operator clues into what's happening before it gets too hot.

 

[echomeister]

sadly, even with all other things; it ain't cleaning the gene pool quick enough. we have several generations of stupid bred together at this point and it's spreading way to fast to stop it now. the worst is that stupid people don't plan having children nor care if they can afford it cause they know the government will pull from others wallets to support them anyways. this results in stupid people being the majority of people breeding and raising children to be just like them (scary). couple generations of that and what do you have?.....................kids these days lol i'm over it, the world is doomed anyways so i'll be happy if people just leave me alone and stay out of my way lol.

Watch this movie, it will scare you ..

http://www.imdb.com/title/tt0387808/