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Yes looks like a ship wheel with a metal tube inside, goo color black.
Homelite Chainsaws
- Thread starter briantutt
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The duckbill valve goes under the tube. Carefully pull the tube out using pliers, clean all the goo out making sure the vent hole in the cap is clear. New duckbill in, flange against the cap and tap the metal tube back in so it seats against the valve.
I believe either a Homelite or Poulan valve works in those. Nice simple design.
When you look at the Stihl and Husky designs compared to that you have to wonder what they were thinking.
I believe either a Homelite or Poulan valve works in those. Nice simple design.
When you look at the Stihl and Husky designs compared to that you have to wonder what they were thinking.
Is this super XL-12 boiling gas or is there a leak?
I was running it hard and its got a new duckbill in the cap.
That sound in the video is my shop fan running, the saw was off and resting on a board.
This was the blue XL-12 yesterday
I'm going to go check my XL12's. I don't remember any of them having stack mufflers?
Are the tanks venting in the right direction? The duckbill end of the valve needs to be pointing toward the fuel tank to allow air in, not the other way around. But I have heard of them boiling fuel, too. I've never seen it myself.
Well the blue one is just venting, but I correctly installed a homelite duckbill in the red super XL-12 .
It is like 90° degrees here but for both saws to do this doesn't make sense.
I only use ethanol free gas with a stabilizer, and Stihl ultra.
All of mine do, one I installed.
One could be slop , but the others are marked/stamped .63.
They will boil fuel. One thing that causes that is a build up of saw cake between the fuel tank and the crankcase
It's easiest to clean out by removing the flywheel and digging / blowing it out. Go from the clutch side as well. Some had a piece of nitrile cord on the clucth side to block that area off.
Saying that, a lot of the older saws boiled fuel and some had carb vapour lock issues due to heat transfer from the cylinder. That's why the carb adapters were changed to plastic and eventually changed to a rubber boot.
I've heard, but don't know for sure, that MACs and Homelites were the ones that are commonly mentioned.
Keeping them free of crud helps a lot.
Poge is correct in pointing to the tank vent as you want some pressure in there to help raise the boiling point of the fuel.
Gasoline can boil boil at around 100 deg F and up to high temps depending upon what's in the blend.
Yamaha 660 Grizzly's were known for that. They moved the tank away from the engine to fix it.
It's easiest to clean out by removing the flywheel and digging / blowing it out. Go from the clutch side as well. Some had a piece of nitrile cord on the clucth side to block that area off.
Saying that, a lot of the older saws boiled fuel and some had carb vapour lock issues due to heat transfer from the cylinder. That's why the carb adapters were changed to plastic and eventually changed to a rubber boot.
I've heard, but don't know for sure, that MACs and Homelites were the ones that are commonly mentioned.
Keeping them free of crud helps a lot.
Poge is correct in pointing to the tank vent as you want some pressure in there to help raise the boiling point of the fuel.
Gasoline can boil boil at around 100 deg F and up to high temps depending upon what's in the blend.
Yamaha 660 Grizzly's were known for that. They moved the tank away from the engine to fix it.
It being almost 100° probably didn't help, but both saws have been cleaned, 1 very throughly.
My concern was that crank case pressure could or was escaping into the gas tank. I suppose if that was happening I would have a flooded saw or see fuel out the muffler.
They will boil when the vapor pressure is reduced quickly, such as when cracking the fuel cap. If you quickly remove the cap and see a sudden increase in bubbling, your duckbill and cap gasket are likely working properly. To add, winter blend fuels are notorious for boiling at lower pressures and can cause problems if you get an abnormally warm day in the middle of winter and on the shoulder season when stations are changing to summer blend. Vapor lock and flooding are problematic on some of my saws when I am cutting on warmer spring days and running winter fuel. If it is a hot summer day and I am making long cuts, I get boiling in my 9xx and 1xx saws. As mentioned, clean cylinder fins really help. Keeping your fuel jug in the shade or even in a cooler with ice, can alleviate symptoms if you can use up the fuel quickly in the saw when refuelling - before heat gets a chance to raise the temp significantly (funny as it sounds). I've kept some 2 L pop bottles of mix on "the rocks" for the scorchers.
If you see bubbles streaming up from the filter, there can be an issue with heat transfer to the carb. That can make it difficult to restart and present other symptoms.
If you see bubbles streaming up from the filter, there can be an issue with heat transfer to the carb. That can make it difficult to restart and present other symptoms.
No worries on an XL-12 as the tank is completely separate from the crankcase.
My redneck valve stem puller...
1. 10-32 tap into stem
2. Fender washer over the stem
3. Claw end of hammer between washer (to protect the cap) and vice
4. Lever the cap off of the assembly.
1. 10-32 tap into stem
2. Fender washer over the stem
3. Claw end of hammer between washer (to protect the cap) and vice
4. Lever the cap off of the assembly.
I tried to delete part of the quote above and it added my reply to the quote. You have to click on expand to see what I said, sorry.
One thing I did do recently was the current fuel mix doesn't have octane boost in it just regular unleaded 87. That might be contributing to the problem considering that the saws were developed when low octane was in the 90s.
ML12
ArboristSite Guru
So far I've only boiled the fuel in 2 saws, a Mac 795 that I was milling with and my pioneer p50. Both times it happened it was 30C+ outside. Other than that I've never had an issue. The pioneer kept running no issues, it was just weird to see the rolling boil in the tank when refilling. The mac would vapour lock, so just set it down for a bit, then restart and keep going.
Well, pulled my Blue and White XL12 off the shelf and it has a stack muffler on it. Then went out to the shed and looked at my Red Super XL Automatic and it has the 3 bolt can muffler. All I remember is the 3 bolt can mufflers, but as a late teens and early 20's guy, what kind of muffler my XL12 had on it didn't rate high on my care meter. I do remember pulling any baffles and spark arrestors out of them to squeek every last bit of power out of them, and you couldn't do that with a stack.
