Chain moves at idle - Stihl 046

[davefr]

I just put a new 25" bar and chain on my Stihl 046 and it moves at idle. The idle speed is set pretty low and if I set it any lower it will probably die. (I would guess it advances about an inch of two per second)

I'm thinking the only possible problem is weak clutch springs. Is it common for them to weaken over time? Can they be replaced without removing the entire centrifical cluth assembly from the output shaft?

Should I just ignore it until the the new bar and chain "break in"? (friction has to be at a minuimum since everything is brand new and freshly lubricated)

 

[HUSKYMAN]

Dave try a slight adjustment of the low speed screw--this will also effect how the saw idles. To test the clutch springs just put the moving chain on a log and the engine will idle even slower or die if it is the clutch. How many hours are on this saw

 

[Rotax Robert]

Your idle may be just a bit to high by about 100 rpm or less maybe. If you know how to re-tune your saw do it but not before pulling your clutch hub and cleaning out the fine sawdust and oil. I find that this debri does cause this from time to time. If you need to know how to do this (and it is simple and should be done often anyway) ask how and I or somebody else will tell you.
One other thing that can cause it is an uneven idle, this you should be able to hear (idle...idle...idle...pop...idle...etc) it may be slightly loading up on you then clearing itself.

 

[davefr]

Thanks for the suggestions and I'll take another look at carburation but I'm 90% sure it's the clutch mechanism because when I compare it to my other saws it has to idle much, much slower to completely stop the chain.

I'll take another look at the clutch components but I did clean out the assembly.

Could the clutch drum be warped which would cause the centrifical weights to engage unevenly?

I'll also try resting the idling bar on wood and see if it cuts, dies, or disengages.

This saw hasn't seen much use. (it's probably still in the first half of it's life.)

 

[confused]

Hey now that davefr has mentioned it my saw 046 does that too and its brand spankin new (well 13 tanks run through) and it has always done that.

Any suggestions?

confused

 

[oakdancer]

Stihl has a problem with overidling I've had it one of the main causes is av rubbers...check the top mount rubber is ok....usually a problem after pulling saw from a cut while x-cutting (worth a try)

 

[Gypo Logger]

Hi There, clutch springs can become heated and stretch if the operator uses the saw with the brake engage of gooses the trigger continualy while pinched. I am not suggesting you have done this but I have seen it before.
Sometimes the clutch bearing can be slightly seized also from rust that will prevent it from turning independantly of the output shaft. This can be easily remedied by removing it and greasing after cleaning it up.
John

 

[homelite360]

coming off from the clutch bearings. i have found that if you take some pb blaster and spray it on hte needles and then put the drum on the shaft and work it a little bit. all of the rust will be eaten off from them and then regreese them and put the clutch back on. good luck.

 

[CMBetz]

Another possibility is that the needle bearings are over-greased, causing drag on the clutch drum, and spinning it. I made this mistake, and fooled with the carb incessantly until I pulled the drum and bearings, and got 2 and 2 put together. It might be worth a try.

 

[Gypo Logger]

Hi Dave, did you check the chain? Maybe it isnt sharp enough.
John

 

[Wade Huggins]

I have invested quite a few dollars over the years in those 046 mags and they are a great saw. The only problems I ever had were clutch springs breaking and intake boots cracking and that wasn't really a problem only on a couple of the dozen that I have had my hands on. I would check the clutch and go from there reset the carb to its proper settings and if that doesn't work replace the boot. Wade

 

[Wade Huggins]

Oh! and of course as gypo stated are you sure the chain is sharp enough? A sharp chain constantly cutting will never have the chance to creep at idle. Keep it cutting an the problem is cured........Wade

 

[stihltech]

clutch

Check the clutch spring ends where they enter the clutch shoe. If they are worn and the clutch shoe hole is worn also, replace the clutch. The shoe will also wear on the spider causing it to rock and grab the clutch drum. The bore of the sprocket drum will wear causing the drum to wobble sideways and touch the clutch. Replacing the worn parts is the cure.