By pressure I mean vacuum and pressure test. I note you only did the vacuum test.
Manual says 7.25 psi pressure and 4.25 psi on the vacuum.
Manual says 7.25 psi pressure and 4.25 psi on the vacuum.
it's always something
- Thread starter mtngun
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DaltonPaull
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I was having problems with my 066 seizing but it tested OK when I vacum/pressure tested it (invested in a mighty vac for that.) Finally I realized that the crank bearings had some play and when you pushed the shaft to the side it would start to leak. I think this might have been causing an air leak during cutting. Someone with more experience than me would have noticed this right off.
Just thought I'd put that out there for one more thing to double check.....
Just thought I'd put that out there for one more thing to double check.....
mtngun
Addicted to ArboristSite
I'm new to vacuum testing, so I don't claim to have all the answers, but it is my understanding that air leaking into the saw (a vacuum leak) can cause a lean condition and damage the saw, but fuel/air mix leaking out of the saw should not harm anything.
According to the suggestions in Four Paw's thread, if the saws passes the vacuum test, it's good to go. But if it fails the vacuum test, then a positive pressure test can be used to pinpoint the leak, by the sound of hissing air, or by squirting soapy water on the seals and looking for bubbles.
Some people like to do both the vacuum test and pressure test. But, the vacuum test makes more sense to me.
I forgot to mention it, but I did spin the crank during the vacuum test.
Other than the idle problem -- which seems to have been fixed by the carb kit -- I had no reason to believe that the saw had an air leak. Until ingesting the sawdust, the saw had always run slightly rich at full throttle with the H screw roughly 3/4 turns out. If it had an air leak, you would expect to see symptoms at full throttle, too, not just at idle.
There was a thread on the chainsaw forum a couple of weeks ago, where Brad Snelling fixed an identical 066 idle problem with a carb kit. brad fixes idle
Well, let's hope I can get the oil pump working satisfactorily, and then I can break in the BB kit and see if the compression gets to where I want it. I'm not real optimistic about the compression ratio on the BB kit.
The primary test is the positive pressure test because that forces the parts apart and checks for leaks in crankcases and joints. Vacuum testing pulls pieces together so is less likely to detect cracks and certain types of gasket problems. In the manual the vacuum test is described as an additional test for oil seals which are more likely to fail under vacuum than pressure testing.
BIG JAKE
Let’s go Brandon!
Nice work Mtn gun. On the oil pump, I'd remove that. Hold the pump in your hand and check for sideplay on the inner shaft. Mine was very sloppy(worn out). It would also leak oil when not in use. I replaced the pump with 1122 640 3201 (for 066-australian HO oil pump) at Lakesides recommendation. Been happy since then and it pumps out a lot of oil-I don't use an auxillary oiler. Doesn't leak oil anymore either. Just make sure you don't lose the seal grommets behind the pump or just replace.
On the compression I've read alot of threads where guys were using OEM rings on these kits. The compression will go up as the rings seat-don't worry. Nice work
Lakeside's oil pump thread:
Part 1: http://www.arboristsite.com/showthread.php?t=31559&highlight=australian
Part 2: http://www.arboristsite.com/showthread.php?p=409998#post409998
Part 3: http://www.arboristsite.com/showthread.php?t=31562
On the compression I've read alot of threads where guys were using OEM rings on these kits. The compression will go up as the rings seat-don't worry. Nice work
Lakeside's oil pump thread:
Part 1: http://www.arboristsite.com/showthread.php?t=31559&highlight=australian
Part 2: http://www.arboristsite.com/showthread.php?p=409998#post409998
Part 3: http://www.arboristsite.com/showthread.php?t=31562
Last edited:
mtngun
Addicted to ArboristSite
Double checking the oiler to figure out why more oil was drooling from the clutch than from the oil slot. This time, I remembered to wear my bifocals, so I could actually see stuff. 
By the way, you can remove the oiler without disturbing the brake band. One less thing to do.
Seals seem to be all there.
Funny how I failed to notice this the first time I inspected the oiler -- when I didn't have my glasses on.
Well, the oiler may be toast, but there's nothing to lose by trying a JB repair.
Let's give the JB a day or two to harden.
By the way, you can remove the oiler without disturbing the brake band. One less thing to do.
Seals seem to be all there.
Funny how I failed to notice this the first time I inspected the oiler -- when I didn't have my glasses on.
Well, the oiler may be toast, but there's nothing to lose by trying a JB repair.
Let's give the JB a day or two to harden.
BIG JAKE
Let’s go Brandon!
opcorn:Good thread Mtngun and you saved some money too with the repair! Will you be able to get some more permits to mill this year?
mtngun
Addicted to ArboristSite
Yep, we received 3.25" of rain in August, so the fire hazard is low now and they should sell me another permit. Only bad thing is that it's nearly a two hour drive to the state land office, and the permits expire after one month, so I keep having to make the drive, over and over. The drive costs far more than the permit.
I don't pretend to understand the logic behind the permitting process, but I try to play along.
I don't pretend to understand the logic behind the permitting process, but I try to play along.
BIG JAKE
Let’s go Brandon!
I wonder if they'd let you work it by mail? Be easy to send them a S.A.S.E. or see if they could extend the permit time to 2 months or more. Worst they could do is say no
mtngun
Addicted to ArboristSite
They used to sell permits by mail or fax or email, but we have a new forester now and he is Mr. Rules and Regulations. It was his idea to make the permits expire after one month. Plus, we have to sign the permit, and our signature has to be witnessed by a state employee. No kidding ! ! ! I don't know what the heck the forester is worried about. There are only 3 families who buy permits for this mountain (and perhaps a dozen more who cut wood without buying a permit). It's not like public lands located next to a big city that get over utilized.
But, state land is the only game in town up here, so I gotta play along.
The JB'd oiler seems to be working. I ran it without the bar for a few minutes, and oil was spurting out the oil slot, but no where else. It was getting dark, so I didn't have time to put it in wood. Maybe this evening.
But, state land is the only game in town up here, so I gotta play along.
The JB'd oiler seems to be working. I ran it without the bar for a few minutes, and oil was spurting out the oil slot, but no where else.
It was getting dark, so I didn't have time to put it in wood. Maybe this evening.
mtngun
Addicted to ArboristSite
An update on the 066 BB project.....
After several tanks of gas bucking firewood, I tuned the carb by ear and proceeded to mill ten boards.
While I was milling, I paid close attention to how the cut "felt" -- was it cutting easily, or was it struggling to maintain rpm's ? Was the saw making more power than the OEM jug, or about the same ? Bottom line -- if the saw made more power, would it cut faster/easier ?
According to my seat of the pants dyno, my BB cut about the same as OEM, or maybe not quite as strong. Sometimes it seemed to lose revs easily if I pushed the feed a little too hard. I did have to baby the feed at times, even on 16" boards.
If the saw had more power, then yes, it would cut faster, because I could feed it faster without bogging. Plus, it would be easier to operate because I wouldn't have to "baby" the feed.
As reported earlier, compression when brand spanking new was 120 psi cold.
Now, with perhaps 10 tanks of gas through it, 125 psi cold at my 4600' altitude. (translates to 148 psi at sea level). That explains the lackluster power.
Is the low compression because the rings are not sealing well, or because the combustion chamber is too large ?
To answer that question, I squirted a generous amount of Fluid Film lubricant into the cylinder, pulled the starter cord a dozen times to distribute the oil, and retested compression. The lubricant should have temporarily sealed any leakage past the rings, yet it only blew 140 psi cold (roughly 166 psi at sea level). So it's losing maybe 15 psi due to leakage past the ring -- that doesn't seem too terrible. It makes me suspect that the low compression is due to an overly large compression chamber.
I had set the squish to 0.020", as tight as I dared, in a deliberate effort to maximize compression. At my altitude, you need extra compression to compensate for the thin air. I'm very disappointed in the low compression.
Long term, I'll be looking for a more powerful milling saw , but for now, this is the only milling saw I've got, so I'll keep running it.
The good news is the JB'd oiler seems to be working fine.
Other good news is the modified air filter setup seems to be sealing perfectly. Here is the filter after the 10 or so tanks of gas. Filthy on the outside........
but not a spec of dust on the inside :yourock:
After several tanks of gas bucking firewood, I tuned the carb by ear and proceeded to mill ten boards.
While I was milling, I paid close attention to how the cut "felt" -- was it cutting easily, or was it struggling to maintain rpm's ? Was the saw making more power than the OEM jug, or about the same ? Bottom line -- if the saw made more power, would it cut faster/easier ?
According to my seat of the pants dyno, my BB cut about the same as OEM, or maybe not quite as strong. Sometimes it seemed to lose revs easily if I pushed the feed a little too hard. I did have to baby the feed at times, even on 16" boards.
If the saw had more power, then yes, it would cut faster, because I could feed it faster without bogging. Plus, it would be easier to operate because I wouldn't have to "baby" the feed.
As reported earlier, compression when brand spanking new was 120 psi cold.
Now, with perhaps 10 tanks of gas through it, 125 psi cold at my 4600' altitude. (translates to 148 psi at sea level). That explains the lackluster power.
Is the low compression because the rings are not sealing well, or because the combustion chamber is too large ?
To answer that question, I squirted a generous amount of Fluid Film lubricant into the cylinder, pulled the starter cord a dozen times to distribute the oil, and retested compression. The lubricant should have temporarily sealed any leakage past the rings, yet it only blew 140 psi cold (roughly 166 psi at sea level). So it's losing maybe 15 psi due to leakage past the ring -- that doesn't seem too terrible. It makes me suspect that the low compression is due to an overly large compression chamber.
I had set the squish to 0.020", as tight as I dared, in a deliberate effort to maximize compression. At my altitude, you need extra compression to compensate for the thin air. I'm very disappointed in the low compression.
Long term, I'll be looking for a more powerful milling saw , but for now, this is the only milling saw I've got, so I'll keep running it.
The good news is the JB'd oiler seems to be working fine.
Other good news is the modified air filter setup seems to be sealing perfectly. Here is the filter after the 10 or so tanks of gas. Filthy on the outside........
but not a spec of dust on the inside :yourock:
That does not sound right. On 16" boards you shouldn't need to baby it. Can you post some pics of your chain?
A bigger or more powerful saw does not automatically generate a significant increase in cutting speed. On narrow cuts, the cutting speed is often chain limited. Unless you UP the chain speed (change sprocket or increase RPM) or drop the rakers the chain is already often cutting as much as it can, pushing won't help, the chain is biting as much as it can and all pushing does is bog the saw.
That you had to baby it is I reckon something else.
That is very unlikely. Assuming everything else is good if the saw is bogging down easily sounds like you've lost torque. what's your WOT RPM and nominal cutting RPM? Sorry to harp on this but did you check the crankcase for positive pressure?
Excellent
That's one positive.
mtngun
Addicted to ArboristSite
Bailey's ripping chain, same as many here use. I doubt if my camera is capable of an adequate chain close-up, but I may try tomorrow. Sharpened with grinder, seems to cut as well after sharpening as it did new. Chain swapped when cutting speed slows noticeably, usually 6 - 8 passes. Same type of chain I have been using for the past year except a couple of months ago I switched to a FOP for the rakers and 15 degrees on the cutters, neither of which made a noticeable difference though it should result in a more aggressive cut.
In fact, the chain specs may be too aggressive relative to the saw's power. Maybe if I went back to 10 degrees and 0.030" rakers, the mill would be a easier to operate without bogging ? I may try that.
If your point is that a sharper chain would cut better, well sure.
But if it had more power, it could maintain RPM in the cut, even when pushed a little too hard.
If it had more power, it could run an 8 pin sprocket instead of a 7 pin.
If power didn't matter, we'd all be milling with 33cc Homelites. Of course power matters.
Exactly. Torque has a lot to do with compression.
I'm afraid Santa hasn't left a tach in my stocking yet.
No reason to, as discussed before. Vac test was good, tune is slightly rich if you believe my ear, plug was very dark, carbon build up on piston top/exhaust port is significant, sides of piston/cylinder are wet and oily, idle is steady. All indications are that it is running slightly rich. What reason do you have to suspect an air leak ? I can't think of any.
Thanks for you comments and questions, BobL. I wish we had the opportunity to mill together sometime. Not much chance I'll ever make it to Oz, though.
BIG JAKE
Let’s go Brandon!
Thanks for the update Mtngun. I may slap on a new OEM top end on my 066 when the time comes. Last I checked it was blowing 155psi (I'm at 5k elevation) and well used saw. I had a chance to pull the trigger on a like new 088 for 800 bones, but with the softwood I cut the saw I have is more than enough power for the job and happy(shoulda bought it anyway! ).Good to see you're back in bidness. You could try slapping in some OEM rings I hear guys doing that. You also might still get a slight increase in compression with continued use if it hasn't run much(wouldn't bet on it tho'). With the saw cold, spray some soapy water on the decomp valve and make sure you aren't losing some comp there. Overall, seems like the inexpensive BB kits are mediocre at best from what posts I've read, although making pistons/cylinders is not rocket science. Anyway, thanks for the update-you're approach to problem solving is very good. Andy(lakeside) always did a vac & pressure test though. But I don't see that would affect your comp reading. Plug good too. Nice save on the oiler! Good thread-tried to rep ya 
).Good to see you're back in bidness. You could try slapping in some OEM rings I hear guys doing that. You also might still get a slight increase in compression with continued use if it hasn't run much(wouldn't bet on it tho'). With the saw cold, spray some soapy water on the decomp valve and make sure you aren't losing some comp there. Overall, seems like the inexpensive BB kits are mediocre at best from what posts I've read, although making pistons/cylinders is not rocket science. Anyway, thanks for the update-you're approach to problem solving is very good. Andy(lakeside) always did a vac & pressure test though. But I don't see that would affect your comp reading. Plug good too. Nice save on the oiler! Good thread-tried to rep ya 
