Ms261c on Aspen issues

[Acerforestry]

I occasionally buy a used saw, and have a query on Aspen use specifically on 261's - I recall a few years back running one of the Stihls on  2 stroke mix for about 4 months from new before making the switch to alkalyte fuel, ( a decision I intended to try to stick with with all ground saw but didn't quite pan out that way) and it wasn't keen on it at all it at, a sod to start and ran really poorly and I switched it to 2 stroke again and used as back up only. Now

have just bought a 2015 model that was on two stroke, vented the tank for a couple of days and put fresh Aspen in, now it won't idle - is this normal? I've not had this issue with Husqvarna's and need to know if the carb is actually the problem before deciding there is a case to return it (Ebay, so that is possible))

Edited 2 hours ago by Acerforestry
spelling

[Dan Maynard]

I've switched to Motomix a little while ago, my finding is all the manual tune saws (Stihl 150, 261, 461, two Dolmars) needed a tweak up on the idle. The autotune saws haven't (Stihl 201, 400).

[kram]

Swapping to aspen/alkalate requires replacing the rubbers.

An arb I know did the switch and had to take 4 saws to the shop with a reasonable expense.

However he also has an 880 that he doesnt use often and doesnt want the expense so still uses 2t just in that.

Edited 1 hour ago by kram

[Dan Maynard]

I worried about this and bought carb kit for the 261 in preparation, but so far not needed anything on any saws. Hedge trimmer had the fuel tank gland harden and start leaking so I changed that gland and the pipes but carbs been fine. Stihl flip cap o-rings have also needed changing, but they were getting a bit old and hard before the switch to Motomix anyway.

 

YMMV as they say.

[Stubby]

1 hour ago, Acerforestry said:

I occasionally buy a used saw, and have a query on Aspen use specifically on 261's - I recall a few years back running one of the Stihls on  2 stroke mix for about 4 months from new before making the switch to alkalyte fuel, ( a decision I intended to try to stick with with all ground saw but didn't quite pan out that way) and it wasn't keen on it at all it at, a sod to start and ran really poorly and I switched it to 2 stroke again and used as back up only. Now

have just bought a 2015 model that was on two stroke, vented the tank for a couple of days and put fresh Aspen in, now it won't idle - is this normal? I've not had this issue with Husqvarna's and need to know if the carb is actually the problem before deciding there is a case to return it (Ebay, so that is possible))

The pump fuel is the problem . The alkylate fuel is just showing it up . Use a saw on alkylate fuel from the get go there will be no issues .The petrol removes the coating on the rubber components but keeps them supple because it is slowly attacking them . Alkylate fuel does not attack the rubber . But , if you have been using pump fuel for some time then switch to an alkylate fuel the rubber components turn brittle and fail because they are no longer being attacked . Change rubber components .  

[nepia]

That applies on saws with some life behind them and is not the fault of the Aspen; it happens because chemicals in the pump fuel have dissolved out rubber softeners present when the saw was new; is my understanding.

Edited 54 minutes ago by nepia

[kram]

I'm not disagreeing however my 020T might be 20 years old, as far as I know all the rubbers are original, and she runs great on E10.

 

Either way, making the swap to alkalte is not something to be done on your daily work saws without some preperation or a spare saw.

[Dan Maynard]

All of which is about the rubbers, not the idle.

 

My 2010 261 is manual carb, I don't know if a 2015 saw would be manual or mtronic?