Which usually wears out first, the clutch or the drum?

[ProfessorGT]

First you need to determine if a lack of power (most probably), or a lack of chutch holding ability (not likely) is your issue. When the chain grabs and stops moving, what does the engine do?

(If the chain was too agressive it could take too big a bite for the engine size, but from the looks of the pics you posted on the chain, it doesn't look like this is your issue.)

If the engine just doesn't have enough power that's one thing, but that could just be because of the state of tune. Have you tried adjusting the carburetor? The high speed needle could be off and therefore severely limiting power.

What happens if you throttle up fully BEFORE beginning your cut? Does it bog down quickly and stall the chain (not the engine) as you begin to cut? Does it only stall the chain when you bear down into the cut? The chain should be sharpened properly so that you do not have to bear down when cutting, but it should allow just the weight of the saw itself to basically make the cut on it's own, with you only having to guide the saw.

I didn't see your cylinder pics, but if there is no severe scoring I doubt that this is the issue. Again I go back to the state of tune. I'd try some carb adjusting, and make sure fuel delivery is not a problem. Make sure the clunk in the tank, and the line to the carb are in good shape and are clear, and are not partially blocked nor pinched. If so, then try asdjusting the high speed needle to see if this gives you more power. If it behaves eratically to the adjustments the carb might need overhauling (due to fuel deposits or trash in the system). This could be causing issues with the carb diaphram also, which will definintely effect power output. If you've never done this before search around online and you will find overhaul info and some good step-by-step guides to help you through it. Just get your carb model number and brand, and you'll find everything you need.

From the looks of it your clutch did get hot (blue coloration indicates overheating - due to slipping) but that is most probably due to the slippage incurred from when the chain stalls and you continue to feed it fuel while the chain is still stalled. Again, my guess is that the issue all boils down to lack of power due to an inadequate state of tune. I'd try to wake it up first by starting with the carb and the fuel delivery system. Heck, I've found brandy-spankin-new Walbro and Zama carbs (complete!) for my 31cc weed whacker engines on ebay for less than $10.00!

Good luck!

 

[smokinj]

Update: took the saw apart again to check out the clutch. Since it was recently cleaned, I could easily see uneven wear on the clutch shoes.

Pictures (each photo is a different "shoe"):

The areas outlined in red are not making contact with the drum.

I also noted earlier that the drum has some side-to-side wiggle play. There are two washers on each side, I think putting a thicker washer on the outside (spur) side would allow the nut to tighten it all together more and lessen the play? Not sure if this would help with the contact issue but an easy thing to try. Are the stock washers hardened? ETA: (Not sure this idea is logical, as the drum will have to spin freely and I can't lock it up, so not sure what the answer is.)

Thoughts appreciated.

I still think its the clutch but as stated before it could be way out of tune as well. Just to make sure Lean it up a little see if it will pull any better through the cut if it doesn't help its the clutch.

 

[quercus_kelloggii]

Ok guys, thanks very much for the feedback. I recently got all set to get a new ring and just try that (but I'm getting frustrated trying to figure out what ring is the right ring), but now I'll try messing with the carb settings to tune it.

Found this http://store.chainsawr.com/blogs/tu...djustment-and-tuning-of-a-chainsaw-carburetor and will try that first and see where that gets me. Also ProfessorGT - I will do some test cuts to see how the saw is performing at the different stages like you suggest.

Greatly appreciated you guys.

 

[amateur cutter]

I've got one of those little saws as well, the clutch looks fine to me. Shoe contact is not always 100% surface contact. Try the tuning & sharpen the chain, keep in mind that it's a very small saw & will stall pretty easily if you "lean" on it. Mine has since new. Also check the oil output & make sure the chain turns freely by hand. I've had mine get fussy with crud between the sprocket & bar. A C

 

[Danno77]

I've got one of those little saws as well, the clutch looks fine to me. Shoe contact is not always 100% surface contact.

I'm with AC on this one. Besides, you may think the contact isn't being made in those places, but given the direction of the spin, One might assume that contact is being made INITIALLY on the front of each of those shoes and by the time the whole shoe engages there isn't any/much slipping, which is causing what you see as wear in the front and non-wear in the rear. Doesn't mean the rear isn't touching, just means that the rear isn't sliding against the drum.

 

[smokinj]

I've got one of those little saws as well, the clutch looks fine to me. Shoe contact is not always 100% surface contact.

I'm with AC on this one. Besides, you may think the contact isn't being made in those places, but given the direction of the spin, One might assume that contact is being made INITIALLY on the front of each of those shoes and by the time the whole shoe engages there isn't any/much slipping, which is causing what you see as wear in the front and non-wear in the rear. Doesn't mean the rear isn't touching, just means that the rear isn't sliding against the drum.

I agree with all of that tune it and you should know for sure what up.

http://web.archive.org/web/20051018212959/www.madsens1.com/sawtune.htm

 

[quercus_kelloggii]

Well I "tuned" the carb the best I could and it didn't get much better. The engine seems to bog down, almost like it is too rich(?), when I let the saw weight carry the saw through 5-6" stuff. Bogs down and the chain stops. Without a load it would rev to what I think was 4 cycle sound. Acceleration was good, maybe a tad boggy at first.

I'm going to take the carb off and apart and clean it out, maybe it really is a fuel issue.

After some test cutting, the saw would cut out on me. I tried tuning it some more and now it is way off base I got tired of pulling the starter rope so much.

I'll pull the carb and clean it out the best I can, check the parts (diaphragm etc) and see where that takes me. Probably couldn't hurt.

Also need to pick up a 5/32 file and hit the chain up, but I think that is a secondary issue if at all.

I'll post again when I get the carb apart.

Thx.

 

[southbound]

Did you buy this saw new??? Why I want to know is so many this can happen to a saw in it's lifetime...

I would try to replace the clutch springs with the correct ones,I'm not saying the ones in there are wrong but they may be..If so they may be to strong and not letting the clutch out properly....

The piston seems to have some carbon build up..Need to be careful you lock it up,, What mix oil you use?? what ratio??? The carb needs to be set right...

I would lose that safety chain as well.. It looks dull in your pic's and they will over work a saw....

 

[southbound]

Check your pm's!

Also if I missed it what does the plug look like and is it the right plug... When I bought my 038 it had the wrong plug and once hot and under load it would act like yours....

 

[quercus_kelloggii]

southbound. Picked the saw up off CL used. I used Arnold all ratio oil (http://media.mydoitbest.com/imagerequest.aspx?sku=760545&size=2&warehouse=C&newsize=200). The saw is supposed to run 32:1. I have no idea how it was treated before me. The cylinder and piston do not look bad from what I know, but I have some new literature to check out on that now/soon.

The plug is correct I believe being a DJ7Y and gaped appropriately at .025, and it looks ok. I have it in mind to pick up a new plug anyway next chance I get however.

I found this off another site, and it is supposedly from a Stihl carb manual, and makes a lot of sense. Maybe I'm going up a rope of sand, feels that way sometimes, but figure it can't hurt to look at the carb more. I don't think it is the clutch or the chain, but I am a newbie and have thought I should just take it in to have someone look at it but I can't afford that. I thankfully have another saw that is good running and will chew through almost anything, this saw was hopefully going to be a backup/limber/small stuff saw. Right now it is a limber at best. I want more out of it if I can pull that off, well, time will tell.

Condition = Engine Speed drops quickly Under Load - Low Power.

Cause = Air Filter Plugged.

Remedy = Clean Air Filter.

Cause = Tank Vent faulty.

Remedy = Clean or replace Tank Vent if necessary.

Cause = Leak in Fuel Line between Tank and Fuel Pump.

Remedy = Seal or renew Connections and Fuel Line.

Cause = Pump Diaphragm damaged or fatigued.

Remedy = Fit new Pump Diaphragm.

Cause = Main Jet Bores or Ports blocked.

Remedy = Clean Bores or Ports.

Cause = Fuel Pickup Body dirty.

Remedy = Clean Pickup Body, fit new Filter.

Cause = Fuel Strainers dirty.

Remedy = Clean Fuel Strainers.

I will definitely sharpen the chain, not in the budget (there is no budget, or very very little) to get a new one I don't think.

The carb, well that needs set/tuned now for sure (I should have counted the turns out from seating from the get go, lesson learned.).

Thanks for your time and thoughts, they are appreciated for sure.

 

[Mainely Saws]

I would also make sure that the muffler is not partially glogged from years of use with a heavy oil . You can use a good quality 50:1 mix in that saw ( todays oils are much better than when the saw was new ) .