Welderman85
ArboristSite Operative
Hello all im trying to learn how to tune saws better but having issues with it stalling. It will cut and idle fine,but as soon as I pick it back up and hit the gas it stalls.
Dumb Tuning questions
- Thread starter Welderman85
- Start date
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Try turning the low speed adjuster out (counter clockwise) 1/4 or 1/2 turn and see if it helps.
This is also assuming your high speed adjustment is close to where it should be (a slight "garble" / 4-stroke sound at wide open throttle and not cutting) but cleans up and runs smooth when cutting.
This is also assuming your high speed adjustment is close to where it should be (a slight "garble" / 4-stroke sound at wide open throttle and not cutting) but cleans up and runs smooth when cutting.
The Shooters Apprentice
Addicted to ArboristSite
First off are you sure you are not having other issues?
SteveSr
Addicted to ArboristSite
What make and model saw are we talking about? Does it stall if you pick it up and drop the bar? What about if you keep the bar tip up?
I to thought low speed might be lean id open it up till it revs quick but doesnt hang rpm's when throttle is realesed.
then reset high.
But not spend to much time because I tune in the wood its kinda pointless flinging bar oil aroundcthe garage
If im unable to get it to run id hand it back to saying it FUBAR
Theres gota be a few hundred vids of steps to tune saws in and out of the wood on youtube
then reset high.
But not spend to much time because I tune in the wood its kinda pointless flinging bar oil aroundcthe garage
If im unable to get it to run id hand it back to saying it FUBAR
Theres gota be a few hundred vids of steps to tune saws in and out of the wood on youtube
Backstage
ArboristSite Operative
That could be an air leak. So here's the thing: with a chainsaw, there's no such thing as "hit the gas". You have a throttle that allows more or less air to enter the carb. That air passing through the carb draws fuel from nozzle jets and enters the engine.
You say that's working normally for the first cuts but once it's warmed up, opening the throttle kills it. That means when it's warm, it's getting one of two things:
1 - way too much fuel and it's drowning/"flooding (usually not the problem, as there's only one source for that)
2 - It's getting way too much air. This is called a "lean" condition. Not enough fuel to provide combustion and keep the crank in rotation. It can also be dangerous because the fuel/oil is the lubricant, and you can cook a saw that way pretty fast. Scored piston/cylinder etc.
It's fairly common for a saw to develop an air leak that exhibits when the temperature changes. Common places are that rubber boot between the carburetor and engine, the crankcase bearings/seals, the decompression valve, and others. Spraying carburetor cleaner around those places can help locate the leak. The saw will suck the cleaner fluid in and it will prevent combustion, immediately shutting the saw down when it finds an ingress point. That'll be where the saw's stealing extra air on the side.
Is carb cleaner the generally accepted "safe" thing to use to look for an air leak?
I have an almost new Poulan 4218 that I rebuilt the carb, it runs strong but I can not get the idle right on that strato piece of junk. No obvious places for a leak but the idle is erratic.
I have an almost new Poulan 4218 that I rebuilt the carb, it runs strong but I can not get the idle right on that strato piece of junk. No obvious places for a leak but the idle is erratic.
Backstage
ArboristSite Operative
Yes. It’s cleaner designed for use on a carburetor. Commonly used for carbon cleaning on all engine parts. If the engine happens to be running while it’s introduced, it just so happens that it’s not flammable, so the saw shuts off. You may end up removing a tiny bit of half burned oil and carbon from your muffler insides at a worst case.
Welderman85
ArboristSite Operative
Sorry it's a cheap strato husky. It was given to me as some thing to tinker with.
Yep I go through many cans of carb cleaner, love the stuff haha. Thanks for the tip, I'll see if I can rule out an air leak with it.
SteveSr
Addicted to ArboristSite
There have been some issues (threads) with erratic ignitions in Huskys. Can you post a video of the issue?
I believe it’s quite flammable. But introducing it into the engine floods it instantly
What model. You realize most saws are strato saws now right.
Backstage
ArboristSite Operative
Worth testing! Or at least fun. Outdoors. Pointing away from yourself. Pointing at the cat is ok.
Works great for taking out wasp nests.
I thought that carb cleaner would dry the oil of bearings and surfaces and was not to be used in running 2 strokes. I could be wrong.
If they stall they won't be running lol.
Tobytronicstereophonic
New Member
May I add this bit of knowledge that took my brain 40 years to finally click:
Faulty Spark Plug or Ignition System.
At idle, there is a much lower pressure in the cylinder when the ignition coil sends its energy to the plug electrodes, so it only requires a relatively low voltage to jump the gap. As soon as the engine rpm increases, the cylinder pressure at ignition rises in step with engine speed...
As the pressure in the cylinder increases, you need more energy to create the spark. This is why a duff plug almost exactly imitates fuel starvation. Starts/runs ok and as soon as you press the trigger, the engine bogs.
The plug needs more energy as cylinder pressure rises and therefore imitates a defective carb or air leak.
I bought a car, a Citroen BX if you're into weird cars, for $50 and drove it 300 miles home. The plug leads had melted on the exhaust manifold. I could still just about drive it if I pressed the accelerator about 1/16th of an inch. As soon I opened the throttle any more, the engine had a huge flat spot. Just like a blocked carburettor (UK spelling) jet. 45 years as a motor mechanic to 'get it'
Faulty Spark Plug or Ignition System.
At idle, there is a much lower pressure in the cylinder when the ignition coil sends its energy to the plug electrodes, so it only requires a relatively low voltage to jump the gap. As soon as the engine rpm increases, the cylinder pressure at ignition rises in step with engine speed...
As the pressure in the cylinder increases, you need more energy to create the spark. This is why a duff plug almost exactly imitates fuel starvation. Starts/runs ok and as soon as you press the trigger, the engine bogs.
The plug needs more energy as cylinder pressure rises and therefore imitates a defective carb or air leak.
I bought a car, a Citroen BX if you're into weird cars, for $50 and drove it 300 miles home. The plug leads had melted on the exhaust manifold. I could still just about drive it if I pressed the accelerator about 1/16th of an inch. As soon I opened the throttle any more, the engine had a huge flat spot. Just like a blocked carburettor (UK spelling) jet. 45 years as a motor mechanic to 'get it'
