Sorry for the boredom gents, but figured I'd post this. I've been moving fast and furious w/ vids today. I tried to be as thorough as possible. Enjoy!
My pressure test vid on youtube
- Thread starter Mattyo
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cre73
Always Lurking, never posting
Thanks for the vid very educational.
Welcome! !
Landmark
Chainsaw Enthusiast
Thanks for the vid and others you do Matt. But i think this subject (vid) has already been covered over here. 
I know I know, I'm late to the party.
Landmark
Chainsaw Enthusiast
Just poking at you buddy. Your vid is betterI know I know, I'm late to the party.
LegDeLimber
Addicted to ArboristSite
Considering how we sometimes we loose links or they get broken,
I'm certainly a fan of having some redundancy.
Oh and kudos for not making it a frigin skinny video!
I'm certainly a fan of having some redundancy.
Oh and kudos for not making it a frigin skinny video!
Dare I ask what a skinny vid is?
hardpan
Addicted to ArboristSite
Thanks. Your videos are outstanding.
Before we press/vac test we must have a reason to be suspicious. In your opinion will a saw H tune to 4-stroke at the desired rpm if there is a small air leak, large leak, any leak? If the H screw tunes fine but the idle speed varies a little (not racing) and cannot be cured with tuning the L screw, is a small leak suspect?
Can mods like porting, squish cutting, muffler opening, and timing advance cause little irregularities that mimic an air leak? In other words, at what point is a saw grounded awaiting an air test?
I'm sorry I didn't see these questions....
I think there is such thing as an irrelevant leak, but I'm not positive on that. I've had idle issues that were carb related, not leak related. Usually leaks are found after the fact...after something catastrophic has happened, or incidentally during a teardown for other reasons. Most of the time, if a saw is running irregularly, i'll suspect a carb issue way before air leak. I'm a big fan of simply tearing things down sooner rather than later... a great opportunity to refresh everything.
can mods....etc.... thats quite a question. as soon as a saw starts running irregularly, it needs to be investigated or risk severe damage. rule out the simple stuff first, fuel, spark, compression. I usually start w/ a comp test. rule out fuel line issues, carb issues, air filter, spark screen, can be many things why saws don't run right. loose spark plug will do it too. hit the high points, do the basics, and if it still isn't running right, tear her down.
does that help?
I think there is such thing as an irrelevant leak, but I'm not positive on that. I've had idle issues that were carb related, not leak related. Usually leaks are found after the fact...after something catastrophic has happened, or incidentally during a teardown for other reasons. Most of the time, if a saw is running irregularly, i'll suspect a carb issue way before air leak. I'm a big fan of simply tearing things down sooner rather than later... a great opportunity to refresh everything.
can mods....etc.... thats quite a question. as soon as a saw starts running irregularly, it needs to be investigated or risk severe damage. rule out the simple stuff first, fuel, spark, compression. I usually start w/ a comp test. rule out fuel line issues, carb issues, air filter, spark screen, can be many things why saws don't run right. loose spark plug will do it too. hit the high points, do the basics, and if it still isn't running right, tear her down.
does that help?
@Bedford T has posted some recent comments in the comments section my video. if anyone wants to translate this for me... please go for it. I don't understand what he is saying
"Matt your vacuum test Is off. the vacuum Is not working right if it holds pressure. it should leak down. move, stop, move stop or a steady slow leak then the valve is operating correctly. I thought helping you was the right thing."
"pressure builds up and it causes the fuel flow to stop of not flow and ypur fuel is no moving around. so the test is a solid hold on the pressure. I use 20 seconds. then change the pump to vac put vac on the fuel circuit. this time the needle should move within 20 seconds and consistently drop. it can sputter and drop or drop slowly consistently. that is the way it works. good luck. bedtime."
I just don't know what he's talking about.... anyone?
"Matt your vacuum test Is off. the vacuum Is not working right if it holds pressure. it should leak down. move, stop, move stop or a steady slow leak then the valve is operating correctly. I thought helping you was the right thing."
"pressure builds up and it causes the fuel flow to stop of not flow and ypur fuel is no moving around. so the test is a solid hold on the pressure. I use 20 seconds. then change the pump to vac put vac on the fuel circuit. this time the needle should move within 20 seconds and consistently drop. it can sputter and drop or drop slowly consistently. that is the way it works. good luck. bedtime."
I just don't know what he's talking about.... anyone?
Let me help you further matt. you were telling your followers that a correct vacuum test means it holds pressure steady. i said that was wrong it should leak down slowly. the pressure test should hold, the vacuum should leak.
if you are going to teach your students you should know this stuff somebody might believe you.
so i took time to take snippets out of the service manual for you can see the steps or you can watch my video. its easy to follow. good luck with it its confusing.
[/ATTACH]
Thanks for that Bedford. My vid is pressure testing crankcases. Your link shows fuel tanks...which have a vent ....
Crankcases have no vent and need to hold pressure and vac absolutely
Crankcases have no vent and need to hold pressure and vac absolutely
"I got an idea why not post a thread and tell everybody your doing another video and what you are saying in the video and ask for feedback from someone who knows. "
"Let me help you further matt. you were telling your followers that a correct vacuum test means it holds pressure steady. i said that was wrong it should leak down slowly. the pressure test should hold, the vacuum should leak.
if you are going to teach your students you should know this stuff somebody might believe you.
so i took time to take snippets out of the service manual for you can see the steps or you can watch my video. its easy to follow. good luck with it its confusing."
So let me help you further Bedford. For the benefit of my "followers" and "students" that might believe you, and if you wish to remain able to post comments to my channel, I expect you to post on my youtube channel and here an apology and an explanation of how you were mistaken. I am not testing gas tanks, but crank cases. It says that in the first 10 seconds of my video. This is a great example of what happens when you either aren't paying attention, haven't done your homework, and/or jump to conclusions
ie "Matt your vacuum test Is off. the vacuum Is not working right if it holds pressure. it should leak down. move, stop, move stop or a steady slow leak then the valve is operating correctly. I thought helping you was the right thing."
You jumped to a conclusion and then called yourself out on it. So, now you got it.... lets get some feedback here on AS from "someone who knows"
oh oh oh.... I almost forgot. You commented at 3am on my channel. You had a response in near around 30 seconds. I then stayed up to give you 4 different sources of "someone who knows" and YOU STILL called yourself out here.
"Let me help you further matt. you were telling your followers that a correct vacuum test means it holds pressure steady. i said that was wrong it should leak down slowly. the pressure test should hold, the vacuum should leak.
if you are going to teach your students you should know this stuff somebody might believe you.
so i took time to take snippets out of the service manual for you can see the steps or you can watch my video. its easy to follow. good luck with it its confusing."
So let me help you further Bedford. For the benefit of my "followers" and "students" that might believe you, and if you wish to remain able to post comments to my channel, I expect you to post on my youtube channel and here an apology and an explanation of how you were mistaken. I am not testing gas tanks, but crank cases. It says that in the first 10 seconds of my video. This is a great example of what happens when you either aren't paying attention, haven't done your homework, and/or jump to conclusions
ie "Matt your vacuum test Is off. the vacuum Is not working right if it holds pressure. it should leak down. move, stop, move stop or a steady slow leak then the valve is operating correctly. I thought helping you was the right thing."
You jumped to a conclusion and then called yourself out on it. So, now you got it.... lets get some feedback here on AS from "someone who knows"
oh oh oh.... I almost forgot. You commented at 3am on my channel. You had a response in near around 30 seconds. I then stayed up to give you 4 different sources of "someone who knows" and YOU STILL called yourself out here.
KG441c
Keith
Lol!!!! When u have the carb blanked and impulse line plugged theres no vent in the rest of the system
Bedford T is in NO position to be instructing people on how to build or maintain saws! Talk about the blind leading the blind!
Pretty simple. Somehow YouTube showed me your video. I clicked it and got up and went to next room and when I came back in I heard you say the pressure should hold.
At 3am or so you could have said no man I am testing the engine when you responded but you said you did not understand what I was talking about. On 2 cycle there is only one vent most of the time that should not hold pressure.
A much as the supporting links were helphuI i was ready for sleep. Simply correcting me on the focus of the engine I would have caught what my ears heard. Then I suggested here for further info.
Without splitting hairs a simple I was talking only about the engine would have solved in in seconds.
So, ban me from your channel that way I will not reach out by accident to help you. Because that was my motive with some jabbing humor. No problems. In fact there is a delete button on the tube, remove anything of mine. Again no problems.
At 3am or so you could have said no man I am testing the engine when you responded but you said you did not understand what I was talking about. On 2 cycle there is only one vent most of the time that should not hold pressure.
A much as the supporting links were helphuI i was ready for sleep. Simply correcting me on the focus of the engine I would have caught what my ears heard. Then I suggested here for further info.
Without splitting hairs a simple I was talking only about the engine would have solved in in seconds.
So, ban me from your channel that way I will not reach out by accident to help you. Because that was my motive with some jabbing humor. No problems. In fact there is a delete button on the tube, remove anything of mine. Again no problems.
Bedford....I have no tolerance for those that don't do their homework. You didn't watch the whole video. Even the minimal that you may have seen...it's obvious that I'm testing the crankcase. So...you weren't even observant at that.....
Then..
You got snarky with me AND wanted to take it to the forum. You made your own bed....and now you are back peddling yet have no humility. Amazing. AND. ...based on the fact you don't care about getting banned from the channel means that my efforts mean nothing to you.
Ya can't make this stuff up folks.
Then..
You got snarky with me AND wanted to take it to the forum. You made your own bed....and now you are back peddling yet have no humility. Amazing. AND. ...based on the fact you don't care about getting banned from the channel means that my efforts mean nothing to you.
Ya can't make this stuff up folks.
Oh....and it's not my responsibility to clarify everything for you....especially when you didn't watch the whole vid. The burden of proof is on you to prove me wrong. ...and ya better do your due diligence before ya do....otherwise here we are.
