038 AVS won’t start

[PaulMon]

Hi Everyone, I’m new here, thanks for accepting me to the forum. I was hoping for some help with my father’s in-laws saw.

I have a Stihl 038 AVS that won’t start for me.
There is not any signs of life at all while trying to start. I have spent quite a few hours cleaning and checking till I’m soar pulling the chord. I have removed the NGK BPMR7A plug and observed sparks. The spark plug is not dry when removed.

There was dirt in the tank so I cleaned it all out and put in new fuel 50/50 mix. I replaced the fuel line, fuel filter and breathe expansion pipe. I removed the Bing carb, removed the gaskets and cleaned gently as best I could. I put the carb in the ultrasonic cleaner for 10m and put all back together. Still no start.
The dealer had the saw last year to replace the start switch spring. I thought I told him to service it but maybe I forgot to mention it. I haven’t used it until now. I never really had any trouble ever getting it to start.
What would the next move be to try and get it going?

Cheers

Paul

 

[Chainmale]

Jeez. I bet my one wishes it looked like that

 

[Chainmale]

Have you tried to get it to fire by putting some mix down the carb?

 

[PaulMon]

Have you tried to get it to fire by putting some mix down the carb?

Hi Chainmale, thanks for replying, I haven’t tried that, I’ll give it a go when I get back this evening thanks

 

[Duane(Pa)]

Make sure the choke flap in the air filter is closing. You don't want 50/50 mix. 50 parts fuel to 1 part oil. I would suggest a little more oil just to be safe.

 

[hacskaroly]

Make sure the choke flap in the air filter is closing.

I agree with this, I have an 075 and an 034 that I have been working on, they were frustrating, had spark, fuel and air, but would not fire. I found that when on choke, they were either not closing or fully closing. Fixing that, they would then fire right up (or at least burp then taking the choke off would fire up).

 

[Woodwackr]

if a little gas in the carb doesn’t get a blip, try a little in the plug hole.

 

[Duane(Pa)]

I'm not a fan of ether for small two stroke engines. I have been able to get some to pop on wd40 if you are looking for an aerosol.

 

[Woodwackr]

I'm not a fan of ether for small two stroke engines. I have been able to get some to pop on wd40 if you are looking for an aerosol.

I just use a piece of fuel line and get about 2” of fuel in the tube, not much.

 

[hacskaroly]

I have been able to get some to pop on wd40 if you are looking for an aerosol.

I like WD-40 too for that!

 

[Chainmale]

I use a small syringe. I can pull some fuel from the tank this way too

 

[PaulMon]

Make sure the choke flap in the air filter is closing. You don't want 50/50 mix. 50 parts fuel to 1 part oil. I would suggest a little more oil just to be safe.

Make sure the choke flap in the air filter is closing. You don't want 50/50 mix. 50 parts fuel to 1 part oil. I would suggest a little more oil just to be safe.

Hi Duane(Pa), The choke flap in the air filter is closing and opening well, I covered it with my thumb just to be sure. Still no joy. I wrote my mix incorrectly I meant to say 50/1

 

[PaulMon]

if a little gas in the carb doesn’t get a blip, try a little in the plug hole.

Hi Woodward, just tried a wee drop into the carb - no joy, Tried a wee drop into spark plug, no joy, I took off the muffler for a look and fuel came out of there. Is that normal? No attempt at all to start, confirmed a good spark too, It’s hard work pulling the brute lol

 

[PaulMon]

I agree with this, I have an 075 and an 034 that I have been working on, they were frustrating, had spark, fuel and air, but would not fire. I found that when on choke, they were either not closing or fully closing. Fixing that, they would then fire right up (or at least burp then taking the choke off would fire up).

my choke looks like it is fully closing in against the opening of the carb. I can see the flap push out as I engage the start switch onto choke. Maybe it’s closing in too close

 

[hacskaroly]

I took off the muffler for a look and fuel came out of there. Is that normal?

Generally if you have fuel coming out of the muffler, then you have flooded the saw (pulled it too many times with the choke on/enabled). To fix this, put the saw on full choke and then pop the lever up to warm start (position c), this locks the throttle into the wide open position, and leaves the choke open too. Now it should take about 20 pulls or so before it starts to sputter and come to life while it is clearing out the excess fuel.

Some people like to pull their spark plug and let the chamber air out for a few hours, but I generally find that it unfloods pretty quickly with the above method. I had many customers bring in their saw thinking it was crap because it would not run (new saws too) and the issue was they had flooded it. Its an easy fix and after showing them they are very happy!

 

[Wonkydonkey]

I'd say you may have put the carb back together wrongly ? And it’s flooded

But I can’t understand that you have an ultrasonic cleaner and just Pulled the carb apart etc and we’re here now . Also Talk about making a bad/wrong fuel mix previously to add to the mess..

I think you dug yourself a hole to China And … think it’s an easy fix
I will add up a correct way of Gaskets and diaphragm replacement for you to double check you put it back together correctly?
( it’s probably not the same carb but the placements/ orders of diaphragm and gaskets is the same.
This is a bling 48 carb diagram


Btw I see that hacskaroly has replied.

 

[Coupe]

Sounds like you could have a flooding problem. Preasure test your carb
and make sure it is holding preasure. And if that is the case putting fuel down
the plug hole is only going to make it worse.Pull the filter and hose out of your
tank take the filter off and plug your preasuse tester straight into the hose.

 

[Woodwackr]

Metering Diaphragm and gasket swapped flip-flopped?

 

[PaulMon]

So I noticed that I had a short to earth when the switch is in choke position or warm start.
Can’t see why or how it’s shorting. Cables look good earth goes from the spring to the bolt on top cover. Black cable goes from pin on switch to side of coil. . So anyway, I removed the earth bolt and followed hacskaroly advice of pulling it on warm start a few times and yes, it give a great few positive blurbs. So I used a cable tie to hold in throttle on warm start and it started. It revs up when the arm is in position. . I didn’t give it too much rev in case I’d do harm at this point. Problem now is it won’t tick over. Once I let go of the throttle it’ll die out.

 

[PaulMon]

Metering Diaphragm and gasket swapped flip-flopped?

I’ll double check that out. ta