372xp sprocket area question

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goatchin

goatchin

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im just a low quanity cutter compared to you guys but yesterday when i was going over my saw after cuttin, i noticed that when i move my chain forwards and backwards in quick motions (i had just set my chain tension), i heard a clanking sound coming from the srocket/drum area.....any guesses as to what the noise is from?? cutts fine and there is no jumping.

thanks for any ideas as to what this clanking noise might be
 
goatchin

goatchin

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okay thanks...i'll check the bearing out tommarow.

how often do you guys change the sprockets?-every couple chains? I've also read that some use either a 7 or 9 drive sprocket-i think thats the right term...why do some run either one?
 
Freakingstang

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check the rim too. If the lines inside the slot have met (from chain wear) it is time to replace it. A worn rim will do just as you described when rotating the chain by hand.
 
pbtree

pbtree

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okay thanks...i'll check the bearing out tommarow.

how often do you guys change the sprockets?-every couple chains? I've also read that some use either a 7 or 9 drive sprocket-i think thats the right term...why do some run either one?

Check the bearing , and take a good look at the rim.

The difference with the pins is picking up chain speed and losing torque...

If you are running a 20 inch bar, you will probably like the speed with a 8 pin. I am using one on my 365, and it is fine. If you are running anything longer, stick with the 7 pin...
 
goatchin

goatchin

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i finally had time to go through the saw today since im not at school b/c of freezing rain and sleet...fun stuff-not. Anyways, i took the sprocket, drum, and bearing off-the sprocket seems to be okay, but im not sure as to what lines Freakinstang is talkin about...maybe some more description as to where and what please??. the bearing had some gunk built up between itself and the crankshaft...this mean it should be replaced or is it just normal build-up.

Pbtree-this sprocket that is on it now is a 3/8 7 tooth. I plan on stickin w/ the 20" bar so when i go to replace the sprocket should i got with the 8 tooth to get optimum performance? right now it seems to have good torque while cutting.
 
stihlfarmer

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A new sprocket will be totaly round and smooth wheras a worn out one will have notches wore into it where the links lay on it creating a groove over time and these notches will eventually meet that is when they need replaced
 
Bowtie

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The first pic shows a worn sprocket next the a new sprocket. The lines are the solid part between the reliefs for the drive links to fit in. When there isnt any solid material between the drive link reliefs, its time for a new rim sprocket. The second picture shows the difference in size between a 7tooth rim and an 8 tooth rim that gains you chain speed and sacrifices torque.
 
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goatchin

goatchin

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wow yea i guess my sprocket is wore out then LOL-looks pretty close to the wore out on in your pic there.

yea if anybody has a pic of a worn drum that would be nice, thanks
 
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Bowtie

Bowtie

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wow yea i guess my sprocket is wore out then LOL-looks pretty close to the wore out on in your pic there.

yea if anybody has a pic of a worn drum that would be nice, thanks

The worn rim I posted I wouldnt be afraid to use again in a pinch, but in my opinion it needed replaced, so I did. They are cheap enough that its silly to question the issue too much.
 
SawTroll

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The worn rim I posted I wouldnt be afraid to use again in a pinch, but in my opinion it needed replaced, so I did. They are cheap enough that its silly to question the issue too much.

Better to change them unnecessarily often than too seldom - they are way the cheapest part of the cutting system...:)
 
pbtree

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Pbtree-this sprocket that is on it now is a 3/8 7 tooth. I plan on stickin w/ the 20" bar so when i go to replace the sprocket should i got with the 8 tooth to get optimum performance? right now it seems to have good torque while cutting.

I run the 8 on my 365, with no trouble on a 20 inch bar. It picked up noticeable speed in the cut actually. If you want to run a larger bar, I would probably stick with the 7. Being as the rims are inexpensive, have both around, If you need to run a longer bar, just swap the rim at the same time you swap the bar!
 
Tzed250

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lf you have been running a chain on a worn rim, then the chain should be replaced with the rim. This is why the manufacturers recomend alternating two chains with one rim. The whole system wears together, then is replaced as a set.
 
SawTroll

SawTroll

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lf you have been running a chain on a worn rim, then the chain should be replaced with the rim. This is why the manufacturers recomend alternating two chains with one rim. The whole system wears together, then is replaced as a set.

Yes, that is the ideal way, but it isn't allways practical (mostly not)....

I manage to do it on some saws, but not all.
 

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