I heard the comment about replacing the spark plug at the engine won't start or checking the compression if it won't start but my first step is much more simple. I get a small medicine squeegee dropper and put a couple milliliters directly into the carburetor with the throttle open. Then you just need to hold the trigger all the way down and pull the cord 5 to 10 times and you'll know right then if everything is good except the carburetor. Of course your compression may be lower than what is ideal but almost guaranteed it's going to run
I got an SRM 225 I just worked on for no spark. And it is at 40 psi!!! It starts on 2nd pull, idles fine and cuts fine too. I imagine it must have had a lot of power when it was new. This one doesn't even look old. But the muffler is wet with blow-by.
Helping my neighbor fix his stihl gas leaf blower. It’s getting a new carb and I decided to do a compression test. I got 90 psi at 5000ft elevation which translates to about 102 psi sea level. Is the more junk? Fires right up but carb issues prevented it from pulling clean at wot
Is the 120 PSI a general rule for small 2 stroke engines? What about 4 stroke like lawnmowers? I just did a compression test on my Echo PB 251 25CC blower and it came out to 116 PSI so I'm glad to know the engine is still in great shape.
Bear's Workshop- Great channel and great videos. Thanks! Comment and Question for you: I'm doing a compression test on my Husqvarna L65 chainsaw (I know it is old...from 1974) I have done a leak down/pressure test and found the crankshaft seals leaking and I have replaced them. After I completed the replacement of the crankshaft seals, I performed another leak down/pressure test and everything held for over 10 minutes. I'm now wanting to put this saw back together but before I do so I wanted to check the engine compression one more time. The compression gauge stopped climbing at 150-160 lbs. But immediately the compression as read on the compression gauge starts leaking out and is back to zero within 45 seconds or so. I'm a novice at this...this is my third 2 cycle engine I've brought back from the dead so to speak. What am I doing wrong, if anything? I've watched yours and other videos and when a compression test is performed, the compression holds. If this is a problem with the rings and cylinder, why didn't this decompression happen when I performed the leak down/pressure test? Comments/advice? Thanks ahead of time.
I would suggest replacing the rings. Should be cheap and easy since you have already disassembled it. It is possible the ring was damaged during disassembly. Also maybe a seal is leaking from when you put it back together? Just some ideas.
I figured out what was wrong...the schrader valve on the end of my compression tester had come loose...I tightened it up and good compression test at 150 plus and it held.
Hey Bear! Good video! I have a barely used 2005 Poulan Pro 3516 35cc chainsaw which looks brand new, but sat for over 10 years and the fuel lines deteriorated. I replaced all of the fuel lines, fuel filter, new carburetor, new spark plug and air filter. Also, I set the gap between the ignition coil and fly wheel properly (one business card thickness). Checked sparkplug with tester and have strong spark. Put fresh 2 cycle oil in chainsaw and good flow to carburetor. Then followed directions for starting (primed and choke out) and nothing, not even a burp! I bought an $18 compression tester like the ones at Harbor Freight. I used the rubber hose that came with it and could not get any compression. I changed to the straight metal pipe and rubber tip and got no more that 65 psi. Any suggestions? Also, are the rubber hoses any good for this test? This is my first tester. Thanks!
@@dusty1498 No, I couldn’t do anymore with it due to shoulder issues. It is on the shelf for now and may work on it in the spring. Thanks for checking on this.
Hey I have a unit that runs really well and I went to check my compression on it because the tester was reading zero on another unit and it read zero as well it’s a weed eater te475y I checked the tester with my compressor and it works fine. Any clue what it could be?
I would guess the adapter you have has something wrong with it. I would assume you have a different adapter for your air compressor. That would be the only thing different.
I heard the comment about replacing the spark plug at the engine won't start or checking the compression if it won't start but my first step is much more simple. I get a small medicine squeegee dropper and put a couple milliliters directly into the carburetor with the throttle open. Then you just need to hold the trigger all the way down and pull the cord 5 to 10 times and you'll know right then if everything is good except the carburetor. Of course your compression may be lower than what is ideal but almost guaranteed it's going to run
You have an awesome channel bro, keep it up!
Appreciate it!
You should check compression with throttle wide open 😊
Thank you. I have a trimmer that wont run with the muffler even though I made sure it was clean. I think compression is my problem.
Have you been able to check the compression?
Great video
Why would you "replace everything" in an attempt to get it running first? Compression test takes 2 minutes. Do that first always.
Thnks good leson
I got an SRM 225 I just worked on for no spark. And it is at 40 psi!!! It starts on 2nd pull, idles fine and cuts fine too. I imagine it must have had a lot of power when it was new. This one doesn't even look old. But the muffler is wet with blow-by.
40 PSI and it still runs! That is incredible.
Helping my neighbor fix his stihl gas leaf blower. It’s getting a new carb and I decided to do a compression test. I got 90 psi at 5000ft elevation which translates to about 102 psi sea level. Is the more junk? Fires right up but carb issues prevented it from pulling clean at wot
Is the 120 PSI a general rule for small 2 stroke engines? What about 4 stroke like lawnmowers? I just did a compression test on my Echo PB 251 25CC blower and it came out to 116 PSI so I'm glad to know the engine is still in great shape.
Yes, 120 is a general rule for small 2 stroke engines. 100 on a 4 stroke small engine is good.
Oil mixer plays a big part 16 :1 and 32:1 ratio , will keep the right compression.
Bear's Workshop- Great channel and great videos. Thanks!
Comment and Question for you: I'm doing a compression test on my Husqvarna L65 chainsaw (I know it is old...from 1974) I have done a leak down/pressure test and found the crankshaft seals leaking and I have replaced them. After I completed the replacement of the crankshaft seals, I performed another leak down/pressure test and everything held for over 10 minutes.
I'm now wanting to put this saw back together but before I do so I wanted to check the engine compression one more time. The compression gauge stopped climbing at 150-160 lbs. But immediately the compression as read on the compression gauge starts leaking out and is back to zero within 45 seconds or so.
I'm a novice at this...this is my third 2 cycle engine I've brought back from the dead so to speak.
What am I doing wrong, if anything? I've watched yours and other videos and when a compression test is performed, the compression holds. If this is a problem with the rings and cylinder, why didn't this decompression happen when I performed the leak down/pressure test?
Comments/advice? Thanks ahead of time.
I would suggest replacing the rings. Should be cheap and easy since you have already disassembled it. It is possible the ring was damaged during disassembly. Also maybe a seal is leaking from when you put it back together? Just some ideas.
I figured out what was wrong...the schrader valve on the end of my compression tester had come loose...I tightened it up and good compression test at 150 plus and it held.
@@kimden85 damn good catch on that tool problem bro!!
do you think at 75 psi the small engine won`t start ?
Hey Bear! Good video! I have a barely used 2005 Poulan Pro 3516 35cc chainsaw which looks brand new, but sat for over 10 years and the fuel lines deteriorated. I replaced all of the fuel lines, fuel filter, new carburetor, new spark plug and air filter. Also, I set the gap between the ignition coil and fly wheel properly (one business card thickness). Checked sparkplug with tester and have strong spark. Put fresh 2 cycle oil in chainsaw and good flow to carburetor. Then followed directions for starting (primed and choke out) and nothing, not even a burp! I bought an $18 compression tester like the ones at Harbor Freight. I used the rubber hose that came with it and could not get any compression. I changed to the straight metal pipe and rubber tip and got no more that 65 psi. Any suggestions? Also, are the rubber hoses any good for this test? This is my first tester. Thanks!
Did you Ever Figure it out? Was it the saw or tester?
@@dusty1498 No, I couldn’t do anymore with it due to shoulder issues. It is on the shelf for now and may work on it in the spring. Thanks for checking on this.
do you at 75 psi the engine won t start?
How to adjust the carb
Good idea. I will do a video on this in the next few days. Hit the subscribe button so you will get notfiied.
Posted a carb adjustment video on the channel.
Hey I have a unit that runs really well and I went to check my compression on it because the tester was reading zero on another unit and it read zero as well it’s a weed eater te475y I checked the tester with my compressor and it works fine. Any clue what it could be?
I would guess the adapter you have has something wrong with it. I would assume you have a different adapter for your air compressor. That would be the only thing different.
$100 on craigslist for parts? “GOOD LUCK”