I would really like to see some kind of range of acceptance for the Homelite 7-29. I have a feeling that 130 psi is too low for this saw, I cloud be totally wrong...
Compression In Different Engines?
- Thread starter Vintage Engine Repairs
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FYI, my snap on compression gauge reads small engines without any issues. It's where the check valve is located that makes the difference. Which is in the end of the hose in all 3 of the snap-on compression gauge sets I have. Don't make broad statements about things you can't prove to be accurate.
Unless the Schrader Valve is malfunctioning, I had it happen once or twice.
Correct, I find it prudent to keep a few spares on hand for this very reason.
Are they color coded for different applications and will; this affect the reading?
The extras I have, have a clear band around them. They don't have much tension on the spring like a normal tire schrader does. I'm not certain if the color of the band indicates anything for certain, it's the same valve that my gas and diesel gauge sets use, supplied from snap-on. However many of my diesel adaptors were bought from various places amd have different colored valves. They all seem to have very weak springs in common though.
I did not read all 4 pages of your post.
Before I go to work on a chainsaw for most anything, especially one that is new to me or for customer repairs I prefer to pull the muffler and look at the condition of the piston.
If I see bad piston scoring I do not whip on a horse that is dying. (I do not make other repairs when I see the engine is bad internally, even if it has fair/good compression.
Before I go to work on a chainsaw for most anything, especially one that is new to me or for customer repairs I prefer to pull the muffler and look at the condition of the piston.
If I see bad piston scoring I do not whip on a horse that is dying. (I do not make other repairs when I see the engine is bad internally, even if it has fair/good compression.
I agree, I rarely take compression readings in a saw or other O.P.E. for that matter. Like you say, it's easy enough to pull the muffler and have a look. However, it's still a valid test for assessing cylinder/ring condition, I'd argue a leak down test would be better but few have/ now about leak down tests and a compression test will get you in the ballpark of cylinder and ring condition all things being even.
sean donato, when I was a kid and probably even before I could drive a car, I wanted to learn all about auto mechanics. Sadly, I would have needed 2 extra years in High School to sign up for auto shop. The guys who took auto shop had to commit to 11th and 12th grade for 3 hours out of the school day. So, I did the next best thing and hit the library for as many books on mechanics as possible. This is where I learned about compression tests, leak down tests and other important knowledge about diagnostics, tune ups ( PRE COMPUTER controlled cars) We are talking 1970's and earlier. All manner of repairs, hop ups, like cams, timing sets, exhausts, head work, oil pressure, greasing, the whole 9 yards.
Now that I became a saw owner and user as of my first saw in 1994, I have learned so much but with the exponentially abundant resources available on the web. Much of my automotive knowledge transfers to small engines, saws, trimmers etc, and the tests available to determine the health of small engines is equitable to the same tests on larger ones like cars and trucks too.
I sold firewood when I was a kid using a Homelite 7-19C.. New absolutely nothing about it other than use burnt Oil in the oiler and 30 weight mixed with the gas in some proportion. Finally got to where it would not run from misuse no doubt.
I started a career and never owned another saw for probably 20 years. Bought a farm, all that good stuff. I bought a Husky 257XP which I think I used one time and decided I needed a weedeater. Money was tight..
So, I took it to the Service Center in Reidsville and Tommy Perkins the since deceased owner pulled it one thump.
Not one pull of the rope. One thump.
Traded me a new weed eater for it.
After I retired an evil person gave me a truckload of Stihl left at the dealership and I got stuck in this crap for the past 20 years.
My opinion, compression gauges are good for taking pictures of when you are trying to sell something,
And, stuff you can't pull by hand.
I started a career and never owned another saw for probably 20 years. Bought a farm, all that good stuff. I bought a Husky 257XP which I think I used one time and decided I needed a weedeater. Money was tight..
So, I took it to the Service Center in Reidsville and Tommy Perkins the since deceased owner pulled it one thump.
Not one pull of the rope. One thump.
Traded me a new weed eater for it.
After I retired an evil person gave me a truckload of Stihl left at the dealership and I got stuck in this crap for the past 20 years.
My opinion, compression gauges are good for taking pictures of when you are trying to sell something,
And, stuff you can't pull by hand.
Zerojunk, I laughed at your message above because YOU and I started life using junk and fixing our junk and now your screen name is 0 JUNK LOL
I also can add a few personal reasons to use comp tester. I can use when buying a saw, I can get a reference point on how my saws start out with me, test in points of time over the years to see how they are holding up over time, etc.
I'm just odd I suppose. I never use a vacuum pressure tester either, other than on a fuel line.
One day last week , I forget which, we got 30 pieces of Stihl equipment in a single day for repair.
Repair is a very loose term. Back to work more accurate since absolutely nothing other than operator error with most.
The only repair that took any time was a hole in the manifold on a MS461 and the impulse line not hooked up at all.
And, through some magic I discovered that without doing any testing other than cranking the dumb thing.
It ain't the space shuttle.
Oh I get this.
Experience and feel can often fix a lot of the obvious and even fix a little " stupid"
I remember when I was a Service Writer at a car dealer back around 1987/88. I got the call from a lady who said she bought a new car maybe the night before. In a heated voice, she said, she wanted us to send someone down to where she was to get her car started. Otherwise, she said she was going to stop payment on her her check.
When our guy got there, he got into her new Audi and as he told me upon returning, he said, " lady, you forgot to put it in Park"
Zerojunk,
I have likely forgotten a great deal of the real hoots, but I can still recall maybe 6 of the best ones.
For reference, we were a Porsche Audi shop. One customer I would call, had his secretary taking my calls. I would explain the diagnoses and costs, then she would tell me she would get back to me after talking to her boss. I told her that his Audi had a coolant leak or other cooling system issue that I needed to explain what was going on to him. When she called back, she told me her boss said that " his car doesn't have a cooling system."
I have likely forgotten a great deal of the real hoots, but I can still recall maybe 6 of the best ones.
For reference, we were a Porsche Audi shop. One customer I would call, had his secretary taking my calls. I would explain the diagnoses and costs, then she would tell me she would get back to me after talking to her boss. I told her that his Audi had a coolant leak or other cooling system issue that I needed to explain what was going on to him. When she called back, she told me her boss said that " his car doesn't have a cooling system."
I suppose as amusing but in a different way the vast majority of repairs I do I think come out to $16.01, which is $15 plus tax. Dirt dauber in muffler, muffler screen stopped up, or flooded.
But, I can do 15 in a decent morning if no train wrecks. So, it is not a cost burden.
Sean is just fine for the future lol. No need to add my last name.
I had several benefits as a kid for figuring mechanics out, grew up dirt poor on the farm. We had to fix everything. Helped that I both my uncles are auto mechanics. Knew from early on I wanted to be a mechanic, just not cars. Went heavy equipment in high-school. Engines are pretty much engines when you get down to it. May be something fancy about how the fuel or air is delivered, but it all crosses over. I've always found working on little stuff quite relaxing, still hate working on vehicles though.
First saw was a Mac 10-10 then pop bought a pm605 at some point. I inherited both when he passed. Sold the 10-10. Never liked it. kept the pm605 for sentimental reasons. Now I got so many saws it's pathetic. Only really ever use 3 of them regularly. Just relaxing to get one going again. Definatly not rocket science working on one.
I encountered the dirt dauber scenario once when a buddy's Uncle was showing me how to rebuild 2 of my Echo String Trimmer carbs. The one didn't sound right once we went to fire it up. He instinctively heard the sound of a restricted exhaust flow. Yup MUD Dauber clogs. This trimmer is my one I use most now.
