HT-KM pole saw chain swap possible

[northernswede]

Looking to pickup a ht-km pole saw for a km131 power head. I saw the chain is a 1/4 picco, any chance someone know if one could swap that 1/4 chain out for a 3/8? Mainly for convenience of not having to get a different set of files or easy file setup from Stihl. I’m assuming not cause the sprocket would most likely need to be changed as well but figured I would double check.

 

[lone wolf]

Looking to pickup a ht-km pole saw for a km131 power head. I saw the chain is a 1/4 picco, any chance someone know if one could swap that 1/4 chain out for a 3/8? Mainly for convenience of not having to get a different set of files or easy file setup from Stihl. I’m assuming not cause the sprocket would most likely need to be changed as well but figured I would double check.

I think you can do it and yes the sprocket is needed.

 

[northernswede]

Thanks, I am gonna see what I can do to find the sprocket, chain and slightly bigger bar. The shop I picked it up at did not know about swapping sprockets or chains so this will be a fun little side project.

 

[lone wolf]

Thanks, I am gonna see what I can do to find the sprocket, chain and slightly bigger bar. The shop I picked it up at did not know about swapping sprockets or chains so this will be a fun little side project.

Before you buy the sprocket check to see if your bar fits that head. Are you able to go try it on?

 

[Franny K]

Say you have an ht 250 which comes with a 7 tooth sprocket and you want the 6 tooth one that is listed in the parts sheet. It was only like $11.00 and has the spring washers included.

I am not absolutely positive about this fitment.

I think my 4 mix is an ht131 and 10 years or so ago they came with the picco 3/8, mirco picco 3/8 on the bar and chain

Pretty sure the 1/4 inch bars for pole saws are 3005 code like lots of stuff on the small displacement end of Stihl's lineup.

 

[northernswede]

I managed to source the following part numbers for use with the chain/bar combo ( I have not purchased or verified yet but I'm close I think )

0000-640-2003 7t sprocket
3005 008 3909 14" bar - ( I'm looking for a 12 still )
Chain would be 50x 1.1mm / 0.043 3/8P

Been interesting research reading up on how Stihl used to release these with 3/8p chain and then switched to the 1/4 and the varying case designs, some with a plastic hook on the end, others with a metal hook.

 

[Franny K]

12" 44dl and 6 tooth sprocket is what you should get in my opinion.

Just for general information, the ht250 less than a year old and the ht131 from 10 or so years ago appear to have the same gearbox unit except for the sprocket and now a 13mm captive bar nut. I forgot about the plastic gearbox or hook, don't have that, contrary to the picture There may be generic replacement gearboxes on ebay. I got a generic angle drive for string and blades.

 

[northernswede]

Gotten pretty tired of hunting and pecking for parts from Stihl for this honestly but I've been able to source from other folks across the pond that the part numbers for the HT-KM pole saw attachment comes with:

3005 000 3909 - 14" bar ( the middle 3 numbers are country codes and not relevant )
3610 003 0050 - chain to accompany - ( matches above bar recommendation )
0000-640-2003 - 7t sprocket

I've got the sprocket, but now to find the bar and chain
I really wish Stihl would get off their duff and make an online parts ordering catalog like Husqvarna offers, it'd save folks like myself who have limited access to dealers and are fully capable of doing their own repairs, or worse, a dub of a dealer ( which I also have ) that much easier.

@Franny K Thanks for the input, from what I could gather the HT-KM comes with a 8t sprocket but previous models came with the 7t and 3/8 bar which is ultimately what I'm after.

 

[Franny K]

The 8 tooth sprocket is for the 71 class Stihl mini 1/4 inch pitch. If you don't believe me that all these pole saw things come with a 6 tooth sprocket except for the ht250 not much I can do. Excluding the 1/4 pitch ones.



https://www.ebay.com/itm/134070038172?hash=item1f37326e9c:g:i2gAAOSwSxliRMRT
https://www.ebay.com/itm/2749700794...GqkSckPje06zcZbbuX0w336xA=|tkp:Bk9SR9DDr9_8YA
https://www.ebay.com/itm/2330344746...s/ciSAhH5upNoKt94ybmdZpyA=|tkp:Bk9SR9DDr9_8YA
Lots of stihl stuff is more expensive on ebay than at the dealer. I put what I paid for a sprocket earlier in this thread.

 

[northernswede]

Hey @Franny K please don't misunderstand my last response. I'm literally unaware of most things Stihl, including pitch, bar and sprocket, and was told for the particular model I have ( which is the Kombi attachment HT-KM ) it has a 8t sprocket. If I wanted to swap out to a 3/8 picco chain and bar, it'd require a 7t sprocket.

I've yet to take my HT-KM apart to verify what sprocket it has and I'll be curious to see if it's a 6t sprocket.

 

[northernswede]

Hey @Franny K please don't misunderstand my last response. I'm literally unaware of most things Stihl, including pitch, bar and sprocket, and was told for the particular model I have ( which is the Kombi attachment HT-KM ) it has a 8t sprocket. If I wanted to swap out to a 3/8 picco chain and bar, it'd require a 7t sprocket.

I've yet to take my HT-KM apart to verify what sprocket it has and I'll be curious to see if it's a 6t sprocket.

Took my HT-KM apart and it’s got a 8t sprocket. The 7t sprocket showed up today so now I just have to source the bar and chain.

Wondering what the difference is between the 6t 7t and 8t sprockets? Is it just to accommodate the chain used or is it for torque or both?

 

[lone wolf]

Took my HT-KM apart and it’s got a 8t sprocket. The 7t sprocket showed up today so now I just have to source the bar and chain.

Wondering what the difference is between the 6t 7t and 8t sprockets? Is it just to accommodate the chain used or is it for torque or both?

Did you keep the crush washers in order?

 

[northernswede]

Did you keep the crush washers in order?

Haven't swapped out yet as I don't have the bar and chain since the only shop near me is 45 mins away.
The crush washers as they came on this unit had 3 coned washers arranged in an order like this ()( #.
Pardon the crude text illustration above but the # would indicate the sprocket.

I'll toss up another pic when I'm back which will better illustrate. The new sprocket looks to be the same thickness, though it came with two flat washers vs the convex'd or cone'd washers from the stock bar.

 

[Franny K]

The 8 tooth sprocket in your picture is marked 1/4p that is for the Stihl 71 series chain not the 13rm 1/4 inch pitch one.

The 7 tooth sprocket in the bag with the spring washers if for 3/8 picco chain either 61 or 63 code in Stihl or generic 3/8lp. The 6 tooth one is likely for the same chain as the 7 pictured, it is what is on my gearboxes at the current time.