Stihl 026 pro carb fuel/air issues

[spudulike]

Oh....take a pic of the saw with the filter on.

[spudulike]

The most common issue with this saw is the impulse line coming off the union just under where the cylinder meets the crankcase in the gap between the rear of the cylinder and the air box but don't see how this meets your failure description as it usually just makes the idle race and over rev at max revs.

Had three in a row just before Christmas!

[adw]

But leaning off when the filter is fitted is the complete opposite of what I would expect, surly we can rule out the filter and the choke? Impulse hose a good shout but surly it would improve slightly when the filter is attached?

[ChrisNewport]

As said the choke is in the air filter, how are you starting it from cold?

[Stubby]

4 minutes ago, adw said:

But leaning off when the filter is fitted is the complete opposite of what I would expect, surly we can rule out the filter and the choke? Impulse hose a good shout but surly it would improve slightly when the filter is attached?

Iths a mysterwy iths a mysterwey someone give me a clue ....😁

[Tom-Gobowen]

Thanks guys got plenty of possible causes to look into tomorrow.

[spudulike]

33 minutes ago, adw said:

But leaning off when the filter is fitted is the complete opposite of what I would expect, surly we can rule out the filter and the choke? Impulse hose a good shout but surly it would improve slightly when the filter is attached?

I know...I know but people sometimes get their facts wrong. I always find these saws damn difficult to start without the air filter as the choke is in the air filter and the saw doesn't like to go without it when cold.

My thinking the air filter fitting is impacting on the throttle linkage somehow as you said, fitting an air filter shouldn't have this effect - I take it the two carb retaining nuts are fitted between the carb back end and air filter?

I added the impulse line as it is the only issue I have had on three consecutive Stihl 026/MS260s so worth a look IMO. 

Sounds a bit like the guy with the backfiring TS400!!

[adw]

Forgot about the TS400 wonder what happened with that, going back to the compensator carb Steve do you understand my thinking, not even sure if it had a compensator carb, but if it does and there is something blocking it the saw would run lean as there would be no atmospheric pressure on the flip side of the diagram, am I making any sense? I have seen it on power cutters where the gaskets have been fitted or after market parts fitted.

[spudulike]

I do understand what you mean, the later MS260 had a compensator carb but this saw may have been upgraded.

In my experience, the saw will run pretty much the same with or without the filter - it certainly wont make the revs go mad high or make the machine stall.

[porky]

Fitted a China impulse pipe of ebay lasted a year. The OEM one I fitted later wasn't that much more.