Pay head to this ^
Many a man has misdiagnosed an ignition by doing what you're doing. Especially on ignitions with cut-in rpms.
Ignition won't spark unless flywheel moving really fast?
- Thread starter B.C.
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Pay head to this ^
Many a man has misdiagnosed an ignition by doing what you're doing. Especially on ignitions with cut-in rpms.
Well, I guess I'm going more by how fast I know the engine should be running by listening & watching the piston, at idle / 1/2 throttle / full throttle. I have done this on five different saws so far.
Husqvarna 136 - spark good at what I would expect a decently low idle speed
Echo 302S - same as Husq
Homelite 150 - older points style, functioned fine once I figured out how to gap the points correctly. (Having trouble sealing the oil casing on this one, so many bolt holes through it)
Homelite Timberman 45cc - must spin very fast, higher than a normal idle.
Stihl MS 192 TC - Same as Homelite, must spin very fast for any spark at all.
Husqvarna 136 - spark good at what I would expect a decently low idle speed
Echo 302S - same as Husq
Homelite 150 - older points style, functioned fine once I figured out how to gap the points correctly. (Having trouble sealing the oil casing on this one, so many bolt holes through it)
Homelite Timberman 45cc - must spin very fast, higher than a normal idle.
Stihl MS 192 TC - Same as Homelite, must spin very fast for any spark at all.
Rx7man
Cattle Rubbing Post
a business card is pretty thick.. try 1 or 2 sheets of plain paper
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After cleaning a sparkplug via soft copper wire brush, I always use some carb cleaner on it. Removes any debris and/or residue.
Can I ask a question and not sound like a complete (insert explicative here)?
Feeler gauges are cheap... why not get a set? I use them on every saw I get. Especially on older points saws...
Really not trying to be a smart ***, and I understand that on a Sat night, it's not like many stores are open, but you get the idea...
I do have a set of feeler gauges actually. Forgot I had them. My smallest 3 in the set are .008, .01 & .12. Although they are flat, and the flywheel round, so I'm not sure I'd be able to use them quite perfectly in this situation. How do you use yours? I guess I could measure different cards against the gauges to emulate each gap and form around the bend. I liked using the card because I could just put it between both pickups and let it magnetize & hold itself in place there & tighten, then pull the card out. Is the difference in gap at those distances significant? I was using a business card and letting the magnets push hard against it, or on one I did it by hand even tighter, like more a sheet of paper but it didn't seem to make a difference either way. One of them with the no spark unless high speed had a pretty big gap at first, I took it wayyy down to almost nothing, but again didn't seem to make a difference.
On the points though that would indeed be a perfect place to use them if the specific gap is known already. The only one I have with points though is the homelite 150, and I just had to keep pulling the flywheel and guessing till I figured it out. Believe it ultimately was about size of business card gap actually. Those points were very touchy though and knowing the exact distance needed and using a feeler gauge would indeed be helpful on those. I'll have to find a manual for it if I ever have to do it again.
On the points though that would indeed be a perfect place to use them if the specific gap is known already. The only one I have with points though is the homelite 150, and I just had to keep pulling the flywheel and guessing till I figured it out. Believe it ultimately was about size of business card gap actually. Those points were very touchy though and knowing the exact distance needed and using a feeler gauge would indeed be helpful on those. I'll have to find a manual for it if I ever have to do it again.
Side note, I have now a Stihl 192 brand new ignition coil on the way as well that I won on ebay. First few days of July I should have both new coils, fingers crossed I might have them both up by the 4th (Or be terribly disappointed if neither works and be out about $35 dollars). I'll shoot off a few fireworks in celebration if I get them both running! haha. Had to buy a new pull start for the Stihl as well so hope that comes in time as well, was missing spring, pawls and retaining clip so I just bought a whole new assembly.
I lay the feeler across the magnet and let it bend with the curve of the flywheel.
For points, if I don't have a service manual, Dad always said, "10, 20, 30." .010 coil, .020 points, .030 plug.
For points, if I don't have a service manual, Dad always said, "10, 20, 30." .010 coil, .020 points, .030 plug.
I lay the feeler across the magnet and let it bend with the curve of the flywheel.
For points, if I don't have a service manual, Dad always said, "10, 20, 30." .010 coil, .020 points, .030 plug.
Cool, I'll have to write that down and remember it. Sounds like a good rule of thumb.
Rx7man
Cattle Rubbing Post
I think that rule of thumb is especially suited to domestic stuff.. all the old magnetos, points distributors, briggs and strattons, etc all used .020" point gaps.. on the imports it might not be quite so standard, though it's probably close enough
A good thing to use for a feeler gauge on a flywheel is brass, nice and flexible and the magnet won't give you grief. If you have a hobby shop nearby they should stock K&S sheets. http://www.ksmetals.com/30.html
Another option is Mylar if you can find some in the right thickness.
Another option is Mylar if you can find some in the right thickness.
LegDeLimber
Addicted to ArboristSite
For low use ,anti-magnetic, flywheel shims?
Grab set of calipers and check some of the various plastic packaging that we're covered up with.
A layer or three of some of those damned clamshell (bulky, "anti-theft") packages that small electronics or mower blades come packed in,
can yield some sheet stock.
Check any plastic bottles too.
Oh and of course, look around at your paper goods also!
Grab set of calipers and check some of the various plastic packaging that we're covered up with.
A layer or three of some of those damned clamshell (bulky, "anti-theft") packages that small electronics or mower blades come packed in,
can yield some sheet stock.
Check any plastic bottles too.
Oh and of course, look around at your paper goods also!
So, a bit of a quick update here, long story short, it seems that the new ignition coils did not make any difference overall. The brand new ones both behave exactly like the old ones on both the homelite timberman 45, and the Stihl MS 192. They both only spark at high speed, the Stihl at VERY high speed. I don't get this. It still doesn't make sense to me why some coils only fire at really high speed. How are you supposed to start it? (Again, gap on coil/magneto is very small, one standard thickness business card. Different gap slightly doesn't seem to matter.)
I also tried various plugs including a brand new direct replacement for the original dj6j champion on the homelite. All behaved exactly the same. I did finally get the homelite started, and it seems to run fine now (will check to see it it takes me 100 pulls again next time it is cold to really know if I've fixed it.) The Stihl however is still a little arsehole and refuses to start. About to tear the carburetor apart...
I also tried various plugs including a brand new direct replacement for the original dj6j champion on the homelite. All behaved exactly the same. I did finally get the homelite started, and it seems to run fine now (will check to see it it takes me 100 pulls again next time it is cold to really know if I've fixed it.) The Stihl however is still a little arsehole and refuses to start. About to tear the carburetor apart...
What is the UT number on your Homelite?
Good question. Whats the best/easiest way to find out?
It's on the tag with the serial number.
Some of those saws had issues, if you have one of these UT numbers
I'll have to save that, thanks! Well, I gave the homelite another try today just a few minutes ago, pressed the prime bulb about 4 times and it started right up after only like 3 pulls. Not going to bother switching the old ignition back on to double check, just going to leave the new one on. I'm really not thinking that was it though, maybe it was the carburetor got a bit loose is my best and really only theory. Seems like its running great now though. There is however one concern on it, it kinda sounds funny like the piston isn't 100% and something is damaged. Everything looked fine in there when I rebuilt it, but this is the only saw I have that sounds that way, but I have no idea what different problems sound like, or if it is fine. I imagine maybe it sounds like a piston slap or a rod knock? No squealing, just maybe like there is play where there shouldn't be? I don't know. Maybe I should take a video and try to capture the exact sound. No idea how to post it here or a link.
Ok, so back to the Stihl 192, it's got serious problems. Last night I did a pressure test on the crankcase, it couldn't hold anything at all. I assumed it was probably the intake boot, so I sealed the intake boot right to the cylinder, as I expected that was to problem, and there was some burn damage from apparent overheating. After letting it sit and coming back to it today and re-performing the pressure test, well, it was kind of a nightmare. There is a hole in the side of the cylinder on the flywheel/stator side, and I have no idea what is supposed to go there, the part is missing as is whatever hose may have been attached to it. I looked around for some diagrams but couldn't really figure out what was supposed to be there an what parts I would need to fix it? ON top of that, the whole cylinder gasket seal is also bad, so beyond these parts I would need to totally disassemble, clean, and regasket the cylinder. It does have good compression though at 125psi, so I'm thinking it might actually be worth doing. That part (gasketing the cylinder) I can probably handle, but I have no idea what these other parts I need are?
I suppose I should probably start a new thread as this doesn't really seem like an ignition problem anymore at all on this saw, its got a whole host of other issues first, then we'll see about ignition.
These sure are a massive pain in the ass to take apart though, I'm kind of curious at this point of some far simpler top handle designs on a fairly light saw even if it doesn't have but half the power. I know some old homelites do, and I might try to get one of those I think I have running. I far less enjoy working on complicated ass hard to assemble/disassemble stuff like this 192.
I suppose I should probably start a new thread as this doesn't really seem like an ignition problem anymore at all on this saw, its got a whole host of other issues first, then we'll see about ignition.
These sure are a massive pain in the ass to take apart though, I'm kind of curious at this point of some far simpler top handle designs on a fairly light saw even if it doesn't have but half the power. I know some old homelites do, and I might try to get one of those I think I have running. I far less enjoy working on complicated ass hard to assemble/disassemble stuff like this 192.
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dougand3
Addicted to ArboristSite
Never worked on a 192T but that hole must be impulse. Usually = brass barb - hose - intake assy - carb.
