How do the points look? Have you replaced the condenser? There is a way to test the coils, but I'd have to get my Google fu on to remember how to test them. Really it's a dead easy ignition system so they arnt hard to trouble shoot.
So bought a chinese saw (holz g070)
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sliceoflife
ArboristSite Operative
Points didn't look bad; but I don't really know what specifically to look for. They weren't corroded or pitted. Did not replace the condensor. Not even sure I can find the correct one.
I ran across an outfit called "digi key" when I was searching for a resistor in a control board in the #$&!!.?$$$# washing machine. The very knowledgeable fellow there was able to cross reference to a compatible part at the cost of peanuts and I was able to circumvent a 375.00 control board.
Anyway, no idea if they can do anything for you, but might be worth a try...
That reminds me, I need a "discontinued" thermistor for one of the &$#!!??ing freezers..
Anyway, no idea if they can do anything for you, but might be worth a try...
That reminds me, I need a "discontinued" thermistor for one of the &$#!!??ing freezers..
sliceoflife
ArboristSite Operative
Oh ok... so google tells me a condenser is just a dumb name for a capacitor... those I know... can probably replace it for pennies if it's got any markings on it.
sliceoflife
ArboristSite Operative
Only marking is the part number, same as the one in the ipl... so not much help.
While I wait on carb kit for the 1130g and the coil for the 1661, figured I'd take the homelite 17 apart as a learning experience.
Coil is scary... coated in white powder... I'm assuming some kind of decaying asbestos infused plastic. A couple gaskets have seen their last minutes many years ago. But otherwise just real dirty. Piston scoring doesn't look that bad in the light, but definitely got cooked... a lot of char on top. I'll practice sanding it. See how it goes. Cylinder looks fine inside. Lot of good nuts and bolts I can snag for other saws too.
While I wait on carb kit for the 1130g and the coil for the 1661, figured I'd take the homelite 17 apart as a learning experience.
Coil is scary... coated in white powder... I'm assuming some kind of decaying asbestos infused plastic. A couple gaskets have seen their last minutes many years ago. But otherwise just real dirty. Piston scoring doesn't look that bad in the light, but definitely got cooked... a lot of char on top. I'll practice sanding it. See how it goes. Cylinder looks fine inside. Lot of good nuts and bolts I can snag for other saws too.
Call digi key. Give them the part #, manufacturer, whatever info is on that condensor. dimensions might even help.
Yes, condenser is just a capacitor of the required spec in a robust housing with the right connections. Most of them have a uF value on the side & any condenser you can find thats similar enough to fit & has a capacitance within about 15% should be fine.
Digikey, Element14, RSonline, Mauser... plenty of electronics parts suppliers to choose from.
A thermistor is nothing special... that particular part number from that particular manufacturer may have been discontinued but there will be a myriad of alternatives with equal or better ratings available for less than the cost of shipping
Digikey, Element14, RSonline, Mauser... plenty of electronics parts suppliers to choose from.
A thermistor is nothing special... that particular part number from that particular manufacturer may have been discontinued but there will be a myriad of alternatives with equal or better ratings available for less than the cost of shipping
You guys beat me to it, yeah condensers are fairly interchangeable. Good chance if it fits it will work. When bad or going out there can be a number of stupid symptoms from no spark, to erratic spark, misfiring, no spark when hot, under heavy load etc. I've been milking the same set of points on my old kohler k-series in my cub cadet forever. Usually it's the cheap condenser that gives the running issues. Easy enough to find though.
sliceoflife
ArboristSite Operative
So gonna look for 22mm length x 15mm diameter condenser... and just hoping the capacitance is close enough.
Digikey said they couldn't match it based on the details I had.
There's a guy selling a bunch of nos homelite xl condensers for a reasonable price. Noone lists dimensions though so I messaging a bunch of sellers with different ones listed asking... hopefully someone with the right size ones gets back to me.
Digikey said they couldn't match it based on the details I had.
There's a guy selling a bunch of nos homelite xl condensers for a reasonable price. Noone lists dimensions though so I messaging a bunch of sellers with different ones listed asking... hopefully someone with the right size ones gets back to me.
sliceoflife
ArboristSite Operative
So the condenser is good.
Ohmmeter across it ramps up to open circuit when saw set to on and is a short when saw killswitch turned to off.
But... only with the coil disconnected... with coil connected there's a short across the condenser at all times.
So IS coil supposed to be a short across the condenser with the saw off? I'd assume not... ie coil is bad, but I don't have a wiring schematic to check... and frankly I have no idea what the internals of this coil look like but I'd ASSUME its crossed coils inside so there is flow via an inductor when the saw is running and it should be an open circuit when saw is off... but that's an assumption.
Ohmmeter across it ramps up to open circuit when saw set to on and is a short when saw killswitch turned to off.
But... only with the coil disconnected... with coil connected there's a short across the condenser at all times.
So IS coil supposed to be a short across the condenser with the saw off? I'd assume not... ie coil is bad, but I don't have a wiring schematic to check... and frankly I have no idea what the internals of this coil look like but I'd ASSUME its crossed coils inside so there is flow via an inductor when the saw is running and it should be an open circuit when saw is off... but that's an assumption.
sliceoflife
ArboristSite Operative
Ok, Now I'm at a loss.
The Coil has ~6k ohm resistance from either lead to the spark plug... which according to some googling is in range.
There is no resistance from lead to lead. Google says this is also correct.
One of the leads is bolted to the stator assembly; with a screw which the manual calls the "coil grounding screw" so I assume that going to ground is correct.
The condenser housing is obviously grounded.
So this means with the starter put together; there will be a short across the condenser; as the lead is tied to one pole of the coil; and the other pole of the coil is tied to ground. Evidently this is by design?
edit: Found a generic magneto diagram...
So the wiring is correct... but there SHOULD be some resistance between the leads of the coil... maybe not much... but some. Might not have set the ohmmetter low enough to read it... off to check again... if there is some resistance, then I'm at a loss... as that means every component; and the system as a whole tests as having the appropriate behavior electrically... but still no spark.
The Coil has ~6k ohm resistance from either lead to the spark plug... which according to some googling is in range.
There is no resistance from lead to lead. Google says this is also correct.
One of the leads is bolted to the stator assembly; with a screw which the manual calls the "coil grounding screw" so I assume that going to ground is correct.
The condenser housing is obviously grounded.
So this means with the starter put together; there will be a short across the condenser; as the lead is tied to one pole of the coil; and the other pole of the coil is tied to ground. Evidently this is by design?
edit: Found a generic magneto diagram...
So the wiring is correct... but there SHOULD be some resistance between the leads of the coil... maybe not much... but some. Might not have set the ohmmetter low enough to read it... off to check again... if there is some resistance, then I'm at a loss... as that means every component; and the system as a whole tests as having the appropriate behavior electrically... but still no spark.
The primary on the coil will be very low impedance, so will be hard to tell from a dead short. Straight resistance won't tell you if the coil is good, only if its not good (if its open circuit). The "real world" conditions the coil works in involve much more electrical stress than a multi-meter can impose on it.
https://www.themagnetoguys.co.uk/condensers-practicalThis site has a bit of information you may find useful.
A faulty condenser won't stop the coil working unless it is shorted or passing current at it's working voltage. They usually just loose capacitance which causes the points to degrade much faster.
Have you used your multi-meter to confirm the points are actually opening & closing electrically?
You should be able to make the coil fire by very briefly connecting ~5V across the primary. Make sure there is a good spark plug (of the correct type) connected to the secondary & grounded to the coils common ground or you risk damaging the coil
https://www.themagnetoguys.co.uk/condensers-practicalThis site has a bit of information you may find useful.
A faulty condenser won't stop the coil working unless it is shorted or passing current at it's working voltage. They usually just loose capacitance which causes the points to degrade much faster.
Have you used your multi-meter to confirm the points are actually opening & closing electrically?
You should be able to make the coil fire by very briefly connecting ~5V across the primary. Make sure there is a good spark plug (of the correct type) connected to the secondary & grounded to the coils common ground or you risk damaging the coil
sliceoflife
ArboristSite Operative
Good news bad news time.
So I decided lets throw a spark plug in their and check the entire system from stator to spark plug electrode for resistance... and it was an open circuit... then a flicker of the resistance I wanted, then open, then gibberish, then open.
So I took the spark plug out, tried another one, same thing, Tried it to the terminal spring and at first I got the resistance I expected; then my grip slipped a little... not enough it SHOULD cause an open; but it did. Put a spark plug back and pinched the terminal cover... and it read correct.
Pulled the wire again... pulled the terminal cover off; pulled the spring out of the wire... and the wire was frayed badly... BARELY contacting the pushpin leg of the spring.
So right back where I started... looks like the only problem was the plug cable... it just wasn't the end of the plug cable I thought it was. Snipped a couple mm off the wire, reassembled and I'm getting the correct resistance at the spark plug terminal.
Now I haven't reassembled for testing yet... but I'm suspecting it'll work once I do.
So Good news... I think I can fix it easy... and almost free.
Bad news... already dropped $40 on the coil I don't need and it's not returnable.
So I decided lets throw a spark plug in their and check the entire system from stator to spark plug electrode for resistance... and it was an open circuit... then a flicker of the resistance I wanted, then open, then gibberish, then open.
So I took the spark plug out, tried another one, same thing, Tried it to the terminal spring and at first I got the resistance I expected; then my grip slipped a little... not enough it SHOULD cause an open; but it did. Put a spark plug back and pinched the terminal cover... and it read correct.
Pulled the wire again... pulled the terminal cover off; pulled the spring out of the wire... and the wire was frayed badly... BARELY contacting the pushpin leg of the spring.
So right back where I started... looks like the only problem was the plug cable... it just wasn't the end of the plug cable I thought it was. Snipped a couple mm off the wire, reassembled and I'm getting the correct resistance at the spark plug terminal.
Now I haven't reassembled for testing yet... but I'm suspecting it'll work once I do.
So Good news... I think I can fix it easy... and almost free.
Bad news... already dropped $40 on the coil I don't need and it's not returnable.
sliceoflife
ArboristSite Operative
Was sure that would have fixed it but nope... back together and still no spark.
sliceoflife
ArboristSite Operative
Got spark.
Pulled the points completely out of the saw... ~60-80 ohm resistance when closed. Filed them better and got that near zero. Reinstalled and It's got spark... not sure that it's consistent/reliable, but I got spark.
Put the saw back together and pulled it over a few times. Got it to fire twice.
POP! then instantly died.
POP! then instantly died.
Other than that a lot of pulling to no avail.
But that's all I've got in me for this morning.
Pulled the points completely out of the saw... ~60-80 ohm resistance when closed. Filed them better and got that near zero. Reinstalled and It's got spark... not sure that it's consistent/reliable, but I got spark.
Put the saw back together and pulled it over a few times. Got it to fire twice.
POP! then instantly died.
POP! then instantly died.
Other than that a lot of pulling to no avail.
But that's all I've got in me for this morning.
sliceoflife
ArboristSite Operative
So spark plug is wrong reach (.307" instead of .375")... not sure if that could cause a severe enough misfire to instantly kill the saw... but maybe?
sliceoflife
ArboristSite Operative
Got the correct plug. Same behavior.
Fired once and immediately died. Then nothing.
Figured I'd check the carb and make sure I didn't do something wrong when I rebuilt it... but I'd check spark one more time before I took the carb off... No spark. Checked point gap. Checked resistances again at every point. Still all the same. Checked all the connections and continuity. Still all good. Just no spark anymore. Back to square one.
Fired once and immediately died. Then nothing.
Figured I'd check the carb and make sure I didn't do something wrong when I rebuilt it... but I'd check spark one more time before I took the carb off... No spark. Checked point gap. Checked resistances again at every point. Still all the same. Checked all the connections and continuity. Still all good. Just no spark anymore. Back to square one.
Damn!
sliceoflife
ArboristSite Operative
Im tired of having to knock the flywheel off/ remount/ repeat between testing. I'm going to just replace the points, condensor and coil all at once and hopefully that'll get it running.
If not; I guess the stator assembly must be defective somehow; or maybe the flywheel magnet isn't strong enough anymore? Neither of those are things I can really replace I don't believe. Have not seen any examples of parts for this saw or parts saws sold in quite a bit of looking.
If not; I guess the stator assembly must be defective somehow; or maybe the flywheel magnet isn't strong enough anymore? Neither of those are things I can really replace I don't believe. Have not seen any examples of parts for this saw or parts saws sold in quite a bit of looking.
sliceoflife
ArboristSite Operative
Found a way to and adjusted the coil/flywheel gap. Polished the magnets on the flywheel and the poles on the stator/coil assembly. Put it back together... Strong spark again out of the saw. Pulled it several times to be sure. It was there every pull.
stick the plug in and try to start it.
Single fire on first or second pull. Pop, dies... won't start again.... pull the plug out and check... No spark again.
Feels like a grounding issue, but multimeter says it isn't. Capacitor (condenser) not discharging possibly? Which causes points to arc; the field to never collapse and thus no spark?
Basically; the saw acts like points gap is too low (no spark), but only after it has sparked a few times.... is this what would happen if the condenser/capacitor wasn't discharging for whatever reason? Google says "no, bad/missing condenser just makes the points wear out faster because of arcing"... but in theory... with a low point gap and no condenser (which is how a capacitor that won't discharge would be modeled after it was charged)... would it possibly just stop sparking?
That brings us back to grounding issue... but it's a potted or at least canned capacitor... so maybe the leg that is soldered to the housing broke and it's not able to consistently reach ground? Would be hard to test/confirm that reliably I suppose. Could miss that type of failure.
stick the plug in and try to start it.
Single fire on first or second pull. Pop, dies... won't start again.... pull the plug out and check... No spark again.
Feels like a grounding issue, but multimeter says it isn't. Capacitor (condenser) not discharging possibly? Which causes points to arc; the field to never collapse and thus no spark?
Basically; the saw acts like points gap is too low (no spark), but only after it has sparked a few times.... is this what would happen if the condenser/capacitor wasn't discharging for whatever reason? Google says "no, bad/missing condenser just makes the points wear out faster because of arcing"... but in theory... with a low point gap and no condenser (which is how a capacitor that won't discharge would be modeled after it was charged)... would it possibly just stop sparking?
That brings us back to grounding issue... but it's a potted or at least canned capacitor... so maybe the leg that is soldered to the housing broke and it's not able to consistently reach ground? Would be hard to test/confirm that reliably I suppose. Could miss that type of failure.
