026 poor throttle response

[redfin]

I apologize for starting this thread but I can't get any google searches to open. I can see the threads with this in the search but can't read them.

I finished an 026 a few weeks ago and have cut quite a bit with it. It starts easily, idles great and cuts well. To this point the parts list is.

1. Impulse line
2. Fuel line/filter
3. Carb kit
4. 16" stihl bar and .75" 50 gauge.

Now to some the "poor" throttle response I'm speaking of may not be that poor at all. The saw doesn't studder, it just isn't nearly as quick to wot as even my 660 is. The only mod I have done is opened the muffler to 125% of the exhaust port. The stock filter has always been clean while trying to tune.

I have tried numerous low needle variations without much change. The only thing could figure is having the .75" chain on instead of a .325" causing more drag. Thoughts?

 

[tolman_paul]

Opening up the muffler to larger than the exhaust port is likley your problem. A little bit of back pressure actually helps the engines performance at low to mid throttle as well as during acceleration. You might want to try restricting the muffler opening to 80% of the exhaust port and see if that helps.

 

[firefighterwolf]

Opening up the muffler to larger than the exhaust port is likley your problem. A little bit of back pressure actually helps the engines performance at low to mid throttle as well as during acceleration. You might want to try restricting the muffler opening to 80% of the exhaust port and see if that helps.

+1

 

[gunnusmc03]

Have you tried another carb?

 

[redfin]

Opening up the muffler to larger than the exhaust port is likley your problem. A little bit of back pressure actually helps the engines performance at low to mid throttle as well as during acceleration. You might want to try restricting the muffler opening to 80% of the exhaust port and see if that helps.

I didn't think of that because all the reading I did prior to the muffler mod pointed to an opening to large would cause idling issues. I can very easily restrict it down and see how that works.

 

[nmurph]

I disagree.

I crank and rev saws all the time without a muffler and they rev like you stirred a hornets nest. I also exceed the 80% rule with every saw I MM and don't have problems.

If it's slow to rev, the it may well be the chain but an 026 should rev fairly well with a 16" 3/8" chain. I've had a muffler modded 026 and it didn't like the 20" 3/8" set up I was running on it.

I would start with verifying the muffler screen isn't clogged and swap out the b/c for a .325" configuration. If that doesn't fix it, then I would check the carb closely.

 

[SEAM]

Might also want to check the choke return spring - or run the saw without air cleaner...

 

[redfin]

I pulled the b/c off this saw tonight because I do not have a .325 to replace with. The saw definately has better response but still isn't what I think it should be.

I put the tach on it and meSsed with the idle and low setting again. It doesn't really like an idle below 3k no matter where I have the low jet (regarding a throttle response that I find acceptable).

Maybe I'm just exspecting to much?

 

[w8ye]

I have a 026 PRO and it is ported and muffler modded.

I run a 16" .375 .050" 60DL RS chain

There is no problem in the rev department.

This saw would not win many 3 cube cookies races but it is a great limbing saw out in the woods. It is one of my favorites.

The muffler has been all opened up on the inside but looks stock on the outside.

 

[H 2 H]

I disagree.

I crank and rev saws all the time without a muffler and they rev like you stirred a hornets nest. I also exceed the 80% rule with every saw I MM and don't have problems.

If it's slow to rev, the it may well be the chain but an 026 should rev fairly well with a 16" 3/8" chain. I've had a muffler modded 026 and it didn't like the 20" 3/8" set up I was running on it.

I would start with verifying the muffler screen isn't clogged and swap out the b/c for a .325" configuration. If that doesn't fix it, then I would check the carb closely.

All of my saws are atleast 100% of the inlet and higher

I have two 026 one with a .325 b/c setup and one with 3/8' b/c and both of them have snappy throttle

 

[redfin]

Am I looking at an over or under fueling condition here?

 

[Wood Doctor]

"I have tried numerous low needle variations without much change. The only thing could figure is having the .75" chain on instead of a .325" causing more drag. Thoughts?"

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Take off the bar and chain and see if it does the same thing. The usual problem for hesitation from idle to WOT is the low speed carb setting being closed too much.

 

[Twisted Priorities]

I would check that the muffler screen isn't plugged and switch out the bar & chain for a 16-18" (.325" x .050"). Then I would check the air filter for restrictions and inspect the carb.