Puzzler....Enjoy

[rd35]

So...a distant family relative (and good friend of my son's) brings me this chainsaw. It's a little Homie XL Automatic top handle single trigger unit....cute little bugger. It was all dirty and dusty. He say's he bought it at a garage sale and wanted to know if I would look at it for him. He hadn't pulled the rope yet. So, over the weekend I get around to giving it a look. Caps off....no oil or gas (good). Pull rope....decent compression but a little rough to turn. Pour in some gas and chain oil....no leaks (good again). Couple drips of mix in the top of the carb, pull and its running. High idle speed. So, thinking I may have a leak at the crank seals I rotate the saw sideways and upside down to see if it changes.....and suddenly it belches out a big puff of blue smoke and dies.
What happened?

 

[rupedoggy]

Look for one of those big containers that says Wast Management on the side and put it in there.

 

[Czed]

get a new duckbill valve
And fuel line's
It will pull bar oil in if the duckbill is missing.

 

[jrs_diesel]

Based on that, it sounds like it was running rich. Fuel mix pooled in the crankcase which went down the transfers when you moved the saw around, which then flooded and died.

 

[rd35]

Czed wins the prize (er, well, Czed is the winner....no prize involved here) . Turns out these saws have an impulse line running from the crank case to the oil tank. There is a duckbill check valve on the end of the impulse hose inside the tank. This pressurizes the tank forcing oil to flow out the oiler line to the bar. So, this is why you don't want to run one of these saws, shut it off, and immediately place it on a surface that you don't want oily (like the floorboard of your pick-up truck) Oil will continue to flow out of that oil tank until the pressure is relieved. They're especially messy if you stop them with the oil tank nearly empty as the air volume is large and it will just keep on dribbling oil for a while. To avoid this problem all you need to do is loosen the oil cap when you stop cutting.
So....what happened with this saw...well the duckbill valve was missing. When I turned the saw upside down the oil in the tank engulfed the impulse hose at the top of the tank and the engine sucked a big gulp of chain oil into the crankcase!
I will try to fix it since it belongs to a family member, but I am not impressed with the design for sure!

 

[alexcagle]

Czed wins the prize (er, well, Czed is the winner....no prize involved here) . Turns out these saws have an impulse line running from the crank case to the oil tank. There is a duckbill check valve on the end of the impulse hose inside the tank. This pressurizes the tank forcing oil to flow out the oiler line to the bar. So, this is why you don't want to run one of these saws, shut it off, and immediately place it on a surface that you don't want oily (like the floorboard of your pick-up truck) Oil will continue to flow out of that oil tank until the pressure is relieved. They're especially messy if you stop them with the oil tank nearly empty as the air volume is large and it will just keep on dribbling oil for a while. To avoid this problem all you need to do is loosen the oil cap when you stop cutting.
So....what happened with this saw...well the duckbill valve was missing. When I turned the saw upside down the oil in the tank engulfed the impulse hose at the top of the tank and the engine sucked a big gulp of chain oil into the crankcase!
I will try to fix it since it belongs to a family member, but I am not impressed with the design for sure!

They work though......All you need is a two dollar part.
Can't complain about that......

 

[Brent Nowell]

Based on that, it sounds like it was running rich. Fuel mix pooled in the crankcase which went down the transfers when you moved the saw around, which then flooded and died.

I agree to this as a good possibility.
Usually this happens to me when the low net is set too rich, like jrs said the fuel/oil mixture pools in the crankcase when it’s idling . Puffs of smoke during idle is a good indication that the low is set too rich, find the sweet spot and you’ll notice after, minimal if not no smoke puffs out the muffler while idling and the engine is at operating temp.

If that doesn’t help run it without oil in the bad oil chamber, if it’s a model in which the oil pump is operated by crankcase pressure then yes it could be bleeding into the crankcase. Without oil in there you can see if this is the problem

 

[rd35]

They work though......All you need is a two dollar part.
Can't complain about that......

Yep, I agree.....but I can't seem to locate a $2 large duckbill valve....or at any price for that matter. All the ones I can find are teeny teeny tiny little buggers that cost $6-8!

 

[Jasonrkba]

Which model is it?