RedMax G300T ignition problem

[calamari]

This is a small, old saw that ran great right up until it didn't. It's old and the plug wire has hardened with time. I shut the saw off the last time and when I tried to start it again a day or so later it acted like I'd flooded it. I pulled the plug and found that the ceramic center of the plug had detached from the metal collar. I cleared any flooding and there's no apparent spark The spark plug wire is now detached from the boot and the wire spring clip is destroyed. I was given a bad coil of some make that had a good sparkplug wire I could unscrew from that coil to use on the RedMax but the RedMax looks like it's epoxyed in place. I've taken the coil off and tried reinstalling it with the business card gap but didn't do anything more than get the coil pickups over the magnets when I did.
My questions are:
Anybody ever take a plug wire out of a RedMax coil? Is it epoxied onto a metal screw that goes into the wire or is it something else that will be destroyed if I dig the wire and epoxy out?
Is it important to set the coil both for gap but also for the slight side to side movement that is at right angles to the air gap?
How does the air gap affect the coils firing? Does it being just a little too tight make it not fire or be weak and the same with too large a gap.
There suddenly doesn't seem to be any spark both before when I thought I flooded it and now after I've Joe McGee'd up a trial fix. It seems odd that the coil just went bad after running fine with a failing plug and being under no stress when it was shut off.

 

[Old2stroke]

For best energy transfer to the coil, you want the coil to be as close as possible without rubbing, the thickness of a business card is understood to be the right gap. Moving the coil around the FW through the small amount of slop in the mounting holes will just change the timing and with an electronic ignition module it won't affect the quality of the spark. If no spark, all you can do for testing is disconnect the ignition sw wire and verify that the coil is securely grounded through the mounting screws, push the spring plug clip back onto the HT lead with the sharp point piercing the center lead and verify that you can get continuity (at least 5Kohms) from the clip to the cylinder. Just hold the plug clip close to the cylinder and pull it over. If you have to replace the HT lead there are ways to do it even if it won't unscrew from the coil. Electronic coils often fail and due to the semiconductor package that controls the current in the primary, there is no valid test you can do with an ohm meter to verify if it's good or bad.

 

[calamari]

Thanks for the complete answer with helpful information.
Prior to posting this question I'd gone to two saw shops and was told they don't have any of those spring clips with one shop suggesting I buy a new saw because parts were no longer available. Now if you can't get a coil or a cylinder I can understand the rationale of a new saw but because those little clips weren't carried seems a stretch.
So since you can't buy plug wire in the correct type and diameter by the foot any longer or apparently those spring clips, what is a good substitute for the clip and what's the best method for replacing the Ht lead w/o removing it from the coil and potentially destroying the coil??
What's left of the RedMax wire is good quality and the HT lead on the bad coil I was given is slightly smaller diameter wire but good quality and it worked for that engine. I have crimp sleeves for making up big game fishing stranded wire leaders that are copper and would result in a secure, small splice with a gap that could be filled with silicone and a couple shrink fit tubes shrunk on top of one another for insulation.
Any suggestions?

 

[Old2stroke]

Thanks for the complete answer with helpful information.
Prior to posting this question I'd gone to two saw shops and was told they don't have any of those spring clips with one shop suggesting I buy a new saw because parts were no longer available. Now if you can't get a coil or a cylinder I can understand the rationale of a new saw but because those little clips weren't carried seems a stretch.
So since you can't buy plug wire in the correct type and diameter by the foot any longer or apparently those spring clips, what is a good substitute for the clip and what's the best method for replacing the Ht lead w/o removing it from the coil and potentially destroying the coil??
What's left of the RedMax wire is good quality and the HT lead on the bad coil I was given is slightly smaller diameter wire but good quality and it worked for that engine. I have crimp sleeves for making up big game fishing stranded wire leaders that are copper and would result in a secure, small splice with a gap that could be filled with silicone and a couple shrink fit tubes shrunk on top of one another for insulation.
Any suggestions?

You can't buy the spring clip that fits onto the top of the plug because it is part of the HT lead cap and not sold separately. Just steal one from a parts saw but make sure when installing it on the end of the HT lead that the sharp end actually pierces the copper wire inside the lead. Soaking the plug cap in boiling water makes it softer and easier to push the lead with the installed clip back into the cap. Grease helps to. You have the right idea about splicing another HT lead to the one on the coil. I would prefer soldering the two wire ends together but the critical thing is to get enough silicone seal around the joint to provide the same insulation as the rest of the wire.

 

[calamari]

Funny story about that boot and clip. The saw shop shows the clip to be ordered from a catalog but they didn't have any in their store so I gave up on them. Yesterday I had reason to be in two auto parts stores and asked about the clip and boot. One store didn't have any but they did have a short lead of the right diameter wire with molded on boots. It cost a dollar so I bought it thinking I might be able to take the boot off and salvage the clip because since it's for a car it probably has a graphite core and not wire.
At the second store I also asked about the boot and clip and the guy went through the mental exercise of trying to figure out where to look. I offhandedly mentioned it was for a chainsaw and he jumped and said he knew just what I was looking for and came back with three boots and three clips, all they had. That was the good news. The bad news was that when he rang the three up it came to $26. I bought all three for reasons you can guess.
You said the coil must be grounded with at least 5K ohms of continuity. The coil on this saw has two screws holding it with two plastic spacers under the coil to raise it to the proper height. That leaves just the screw heads to make contact with the case through the threads. I'll check for continuity though.
Is it possible to get the saw out of time enough due to the slop in the screw holes such that the coil won't fire?

 

[Old2stroke]

Funny story about that boot and clip. The saw shop shows the clip to be ordered from a catalog but they didn't have any in their store so I gave up on them. Yesterday I had reason to be in two auto parts stores and asked about the clip and boot. One store didn't have any but they did have a short lead of the right diameter wire with molded on boots. It cost a dollar so I bought it thinking I might be able to take the boot off and salvage the clip because since it's for a car it probably has a graphite core and not wire.
At the second store I also asked about the boot and clip and the guy went through the mental exercise of trying to figure out where to look. I offhandedly mentioned it was for a chainsaw and he jumped and said he knew just what I was looking for and came back with three boots and three clips, all they had. That was the good news. The bad news was that when he rang the three up it came to $26. I bought all three for reasons you can guess.
You said the coil must be grounded with at least 5K ohms of continuity. The coil on this saw has two screws holding it with two plastic spacers under the coil to raise it to the proper height. That leaves just the screw heads to make contact with the case through the threads. I'll check for continuity though.
Is it possible to get the saw out of time enough due to the slop in the screw holes such that the coil won't fire?

That is a real horror story with the plug clip. Rotating the coil through the slop in the mount holes will NOT prevent the coil from firing (as long as it's an electronic coil). It just changes the timing. Do some simple geometry, most coils will only allow about 5 degrees change by how it's mounted and that shouldn't prevent starting, however if you have a coil with a lot of retard to make starting easier, it might be enough to give too much retard so mount the coil with it rotated as far counterclockwise as possible for most advance.

 

[calamari]

Again, good info. Thanks
Now for another horror story. I need the saw to do trimming on a big oak my friend and I are cutting down next week. I resigned myself to having to buy a new top handle saw just so I'll at least have spare parts available in the future. I was going to buy the small Echo but they won't allow it to be shipped to Calif. for emission reasons I assume. Buying a Calif. saw locally was another $75 but when your screwed sometimes your proper screwed so I bought the Stihl MS 194T that was on sale for only $409. See comment about proper screwed.
The local hardware guy was very helpful and willing to discount the Stihl gas and oil and had the saw filled with fuel and oil for me. He started it eventually (not as easy as my Dolmar) and winged it up a few times to clear it out. Then when it returned to idle there was the most horrific bare metal screeching sound. Wing it up and no screech so I assumed it was one of three things. The chain brake not being right, the clutch basket dragging on the clutch shoes or the needle bearing in the clutch destroying itself. He said that they'd just taken the Stihl brand on and didn't have another to exchange for that one. He said that it may just have to be run to"Break it in" but that screech wasn't the sound of something seating in. I'm taking the clutch off today and looking at the needle bearing and making sure it's lubed. Other than that I'll just run it till it blows up because he said they'd fix it since they saw it was happening as soon as it started. Another reason I don't like Stihl saws.

 

[calamari]

Update on the Stihl.
Took the clutch apart and saw no scoring on the wear surface of the sprocket basket. Looked at the needle bearing and it was dry and the nose of the crankshaft was black in a cross between some sort of coating /heat treatment and high heat bluing. Since the needle bearing seemed OK I assume it's a wear treatment. I lubed the bearing and shaft with grease and reassembled...no more noise. If that truly solves it you'd think Stihl would spend the 1/4 penny's worth of grease to lube it during assembly.
Next update will be if I ever get the RedMax fixed or I put it on the mantle piece.

 

[calamari]

Well, I give up. I added a new length of primary ignition wire to the shortened wire and tried to get a pop...nothing. It goes on the mantle I guess.
The MS194T Stihl is completely broken in and still makes that screeching sound at low throttle. It's no better than the Redmax as far as power with the exception that it runs and the Redmax doesn't.
Stihl only has a 3 month warranty for top handle saws unless you buy some Stihl gas or oil when you purchase the saw. Nobody told me at the store so I've got 2 months left. First and last Stihl I'll buy.

 

[Twinfield]

Did you ever find out what was causing the screeching sound from your 194T? I had one and I lubed the needle bearing real good and the noise went away for a while but is back again. I can't find anything from Stihl about the issue.