Stihl 026 wont run.

[BOB K.]

I was given a Stihl 026 with a new carb, fuel line, filter and impulse line. Installed everything and it will only start with a shot of starting fluid. Seem like it is not getting fuel. Checked everything and all looks good. Any thoughts, I adjusted the carb screws 1 turn out. thank you

[sawguy21]

First of all ditch the starting fluid. It is very hard on two stroke engines particularly the crank seals. That is an old saw, remove the muffler and inspect the piston through the exhaust port. Is it scored or galled (metal transfer)? Was the fuel filter replaced? Is the fuel fresh and properly mixed with a quality 2 stroke oil? Is the park plug tip a nice light brown and is it properly gapped?

[Guydreads]

X2 what Sawguy said. Aftermarket or OEM carb? Some aftermarket carbs decide to not work. Personally I've had very good luck with aftermarket carbs, but some people just don't. Is the impulse hose connected and not clogged, are there any cracks in the impulse hose?

[BOB K.]

It is a aftermarket carb. It has new impulse line, fuel line`, spark plug and filter. Not sure how old the gas is but I only use Stihl or Echo oil.

[ehp]

check the off and on switch , Have seen lots of 026 where the metal tang some how ends up on the wrong side so the saw is always off cause the switch is grounded 

[BOB K.]

Thanks nehp, It has spark and will fire with starting fluid. Which sawguy21 said is a nono, learn something new everyday. I will get fresh fuel and check piston and impulse hose again this week.

[ehp]

needle is stuck in the carb at the needle and seat , tap the carb with a small wrench and drop a couple drops of your mixed gas down the throat of the carb and start saw and see if needle will come loose

[LogDog55]

If it has spark and compression, I would be very suspicious of the carb. Especially if it's chinaesium one. I've had many come DOA for a variety of quality control issues. 

[PoginyHill]

I had an 026 years ago. If I recall correctly, it had similar symptoms as yours. Finally determined it had a cracked cylinder, where it is fastened to the crankcase. Tossed it out and got a new one (391). Problem solved.

[DHansen]

I like the input from eph, good post and good advise.  That is the direction I would go with your diagnosis.  Do you still have the old carburetor?

[joe_indi]

First remove the carb, squirt a few drops of oil into the impulse hose, and crank the saw (with spark plug removed.
If no oil squirts out the impulse is weak and needs to be checked further
But if the oil does squirt out the carb'd ability to pump fuel needs to be checked. For doing that, fit the carb back with the nuts tightened, no air filter base,  no top cover on the carb. Keep switch  off. Press the metering lever and pull the recoil a few times. If the carb is pumping fuel it should spurt out. If it does not you need to check the pump side of the carb.Maybe the strainer is blocked or maybe there is an air leak.
If fuel does spurt out, check the level of the metering lever. Aftermarket carbs sometimes have stiff diaphragms so the metering lever might need to be adjusted for earlier opening of the valve

[Guydreads]

@joe_indi I just learned so much from your post. Thanks for sharing that. I was aware of these issues, but never how to test them efficiently. I had a no impulse issue a while ago from a clogged port below the cylinder. The oil in the line would've helped me so much. And then taking the cover off the carb with metering lever depressed is another great idea I had never thought of. 

[BOB K.]

Sorry guys things have been crazy so I have not had a chance to look at it again. The info is incredible help and will try it all. I do have the old carb and another new aftermarket. I changed  the carb because it was given to me with old fuel and would not start so I figured it would be gummed up. I picked up fresh gas, oil and stabil today and will dump out the old gas.

 I bought the other carb for the MS261 which was also given to me but only has 50lbs compression. But that is a complete other project for latter. lol 

[BOB K.]

So nI worked on the 026 today and did what Joe Indi  said. The oil did spit out the impulse line so put it back together with the other new carb I had and new fuel. Still nothing. Not sure what he ment with the metering lever unless he means the lever the throttle linkage goes to? I have another new fuel line and filter and will give it a try tomorrow.Maybe when I put it in I made a hole somewhere.

[joe_indi]

Not sure what he ment with the metering lever unless he means the lever the throttle linkage goes to? .

I meant the fuel metering lever. I used an old carb to show what a rich setting and a lean setting of the lever can look like. If it is too lean the fuel will not be drawn into this chamber. If it too high and rich it could flood the engine. TLC recommended when adjusting this lever

 

 

 

[BOB K.]

Well I went to replace the fuel line and filter and ripped the new hose. Now I need to order a new  one. Iwas trying to get the grommet in, used a little oil hoping it would pop in, NOPE. I was wondering if I took the OE carb put it in a ultrasonic bath would it clean it without rebuilding it?