2 Chainsaws, 1 Blower - Would not fire with Gas or Starting Fluid

[etbrown4]

I know this sounds unlikely so I'll cover the items checked so far on all 3 pieces of equipment:

Good Compression
Good fresh gas, oil mixed properly
Spark appears to be ok and blue
Spark plugs new
Plug when removed after pulling starter, is slightly moist
All 3 carbs thoroughly gone through and clean
L and H screws set at 1 3/4 out

Until running into these three units, I'd never seen a 2 cycle motor with good compression and a spark that would not fire on starting fluid, or a mist of gas/oil mixture. For me, it's sort of like....how is this even possible?

One of the three I finally got going with much adjusting to the L&H screws.

I'm stumped on the other two.

Suggestions welcome!

 

[Adirondackstihl]

Flooded.

Start with H & L @ 1 turn out. Go from there.

Dont use starting fluid BTW

 

[Guido Salvage]

Flooded.

Start with H & L @ 1 turn out. Go from there.

Dont use starting fluid BTW

Yup, remove the plug and dry it and pull it over a few times to clear the excess fuel. Reinstall plug (checking for propper gap), adjust carb to 1 turn out from lightly seated, set the choke and start. Never use starting fluid, it will wash the oil off the cylinder wall.

 

[Fish]

I blew up a Ryobi on starting fluid once......

True.

 

[etbrown4]

OP here.

Yup, we all know that starting fluid is not recommended. A mist of oil and fuel mix will perform similarly, and more safely.

My bigger question is why these puppies won't start, at least on the starting fluid or a mist of fuel, because with it, you temporarily bypass the carb, fuel filter, and fuel lines.

With good compression and a seemingly good blue spark, it would seem that the engine just has to fire when pulled over.

It's not flooded, with a light mist of fuel.

I've seen plenty of motors with the intake and carb completely removed, where you could spray a little gas or starting fluid into the intake, and away they go, for a few secs.

Other than starting with H&L at 1 turn out, does anyone have an idea why these 2 strokes as described, won;t seem to fire and run for at least a few seconds.

I wonder what could be preventing the firing, and what else to try.

Tips appreciated.

 

[Fish]

OP here.

Yup, we all know that starting fluid is not recommended. A mist of oil and fuel mix will perform similarly, and more safely.

My bigger question is why these puppies won't start, at least on the starting fluid or a mist of fuel, because with it, you temporarily bypass the carb, fuel filter, and fuel lines.

With good compression and a seemingly good blue spark, it would seem that the engine just has to fire when pulled over.

It's not flooded, with a light mist of fuel.

I've seen plenty of motors with the intake and carb completely removed, where you could spray a little gas or starting fluid into the intake, and away they go, for a few secs.

Other than starting with H&L at 1 turn out, does anyone have an idea why these 2 strokes as described, won;t seem to fire and run for at least a few seconds.

I wonder what could be preventing the firing, and what else to try.

Tips appreciated.

What make/models are they?

 

[DEG305]

Oh no, dont tell me that you used "starting fluid"! Dont you know it will blow up every thing in sight! shouldn't even have it in the garage. One squirt of the bad stuff will suck the piston clean out the muffler and leave you wondering "what the h*** went wrong. After all it says on the can that it's safe to use on 2stroke engines. GIVE ME A BREAK!!!!:msp_scared:

 

[Nardoo]

Flooded......broken flywheel key......plugged muffler? Sure the coil can produce spark under compression? How good is the compression?

 

[D&B Mack]

I have had this problem twice before.

The end cause was the same in both cases, tank lining sucked into the carb.

The first time was saws left sitting with ethanol fuel in the tanks, lining broke down and went into carb.

The second time, someone used the high concentration star brite in the mix fuel cans and this ate the lining off, sucked it into the fuel tank.

The second time was 7 saws, the first time was three saws.

If all three went bad at the same time, it is high probability the fuel is the culprit.

My rule has been, if you need starting fluid for 2 cycle, there is a mechanical problem. Fix the problem rather than using a band-aid.

 

[etbrown4]

The compression ranges from 120 to 140 on the 2 remaining, non starting units.

The saws are Craftsman 40cc, not sure of the model #. As mentioned earlier, I finally got one saw going by working with the L&H screws. The blower is an Echo PB403T.

Fuel has been changed out and works fine in other equipment currently, carbs cleaned down to the needle and seat and all orifices.

Regarding the tank lining. I've thoroughly cleaned the tanks, and replaced all lines and fuel filters, and been through the carbs completely.

Other than the tank lining situation, curious if other have seen any 2 cycle that would not fire on a mist of gas or (starting fluid not recommended) straight into the intake where there was good spark and compression. I know I never have, until now.

I always figure, good spark, good compression, enough fuel, and you have fire!

 

[northmanlogging]

could be the ignition timing is messed up, broken key on the fly wheel or loose bolts holding the ignition module on. you would still get spark just not at the right time, be it to early to late, whatever, Also a fouled plug will sometimes show good spark outside the cylinder, but under compression it takes a dump.

 

[dboyd351]

could be the ignition timing is messed up.

That would be my guess.

 

[zogger]

I blew up a Ryobi on starting fluid once......

True.

ya, but it was Pearl Harbor day and you are just a patriotic guy and stuff

 

[zogger]

The compression ranges from 120 to 140 on the 2 remaining, non starting units.

The saws are Craftsman 40cc, not sure of the model #. As mentioned earlier, I finally got one saw going by working with the L&H screws. The blower is an Echo PB403T.

Fuel has been changed out and works fine in other equipment currently, carbs cleaned down to the needle and seat and all orifices.

Regarding the tank lining. I've thoroughly cleaned the tanks, and replaced all lines and fuel filters, and been through the carbs completely.

Other than the tank lining situation, curious if other have seen any 2 cycle that would not fire on a mist of gas or (starting fluid not recommended) straight into the intake where there was good spark and compression. I know I never have, until now.

I always figure, good spark, good compression, enough fuel, and you have fire!

happened to me once with a normally great running trimmer, I was stumped until I pulled the muffler and found the mud dauber nest

 

[stihlrookie]

Clean the muffler screens if they are present and slap a couple new spark plugs in. May just be that simple.

 

[Stihlofadeal64]

happened to me once with a normally great running trimmer, I was stumped until I pulled the muffler and found the mud dauber nest

No no no Zogger it is a mud dobber nest -- stick to the southern slang here! I did laff out loud when I realized I've probably seen a ga-zillion of those nest in my short span of life!

 

[McCulloch1-52]

this happen to me before with two saws they would not fire change spark plug did not help waited the next day started right up.

 

[zogger]

No no no Zogger it is a mud dobber nest -- stick to the southern slang here! I did laff out loud when I realized I've probably seen a ga-zillion of those nest in my short span of life!

if you insist, this is how I hear it being said

muddaahburh

kinda sorta, all one long word..

dang things can be dangerous, I had a big one plug up my propane furnace in my first RV, caused the exhaust to..not exhaust....

small guys can be fun, one day I am pouring gas into the snapper from the five gallon jug, look at the handle, about 1 mm from my hand this black widow is sorta hanging around there.

Finished the pour real gently like, flicked it off...

Get them things under the trucks all the time, slide under to work on something oh, hai!

I try to not annoy the arachnid overlords...

 

[fearofpavement]

Yeah, black widows, scorpions and yellow jackets are the scourge here in middle Georgia. I picked up a pile of junk at an auction a few months ago and while loading it I think I found every black widow in the county hiding amongst it. Never been bitten by one but....

I did get into a huge nest of yellow jackets one time and they stung me numerous times. >20.

One of our Amazon pilots was just bitten by a jararaca viper (snake) a couple days ago. He was able to get anti-venom and is pulling through. yikes!

On a brighter note, I sold the first cord of wood in the last two years yesterday. It's hard to market firewood when tornadoes keep coming through and saturating the market.

 

[dboyd351]

this happen to me before with two saws they would not fire change spark plug did not help waited the next day started right up.

I think this indicates the saws were flooded and the gas dissipated while they sat overnight. The suggestion to pull the plug, dry the plug off and pull the recoil several times while the plug is out to get rid of the excess gas should take care of flooding, unless it it really bad. I know OSHA wouldn't recommend it, but I've even held a butane lighter to the spark plug hole to burn off the extra fuel. Usually generates a nice POOOF!