Service & Maintenance Question
What the specs for the coil on a 445 Husqvarna. I need to...
Service & Maintenance Question posted September 15, 2014 by Bob Russell
1283 Views, 7 Comments
Question:
What the specs for the coil on a 445 Husqvarna. I need to test it to make sure it is good.
Answer
hello mr. Russell, if using a gaugeable spark tester, start with the contact run out to 6mm, if unable to witness the jump, then run it back in 1mm at a time. ie. 5mm-4mm etc, til witnessing the jump. the simple and fast way to verify if the igniter is up to the challenge, is to simply remove the plug from jug, plug it back into the boot, ground the base of plug to jug and sharply pull the recoil starter in a darkened area of your shop. you should clearly witness rocket fire within the plug gap. if no spark, then re-do the same test with a known quality plug. that will tell the tale... good luck...
a test result jump below 4mm indicates the coil igniter is weakening and smart money buys new...
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if having trouble getting it started, b-4 addressing potential carburetor problems, manually close the compression relief valve. its tougher to pullstart, but you should eliminate the CRV as a possible source of the no-start right away. those valves can stick in the open position when brand new, and Husqvarna saws will not start with the CRV stuck open. I learned this the hard way after addressing all other possible reasons and then finally arriving at this issue.
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I checked all the items you talked about. I pulled the plug out and checked for spark and got none. I pulled off the kill switch and tried again, same thing no spark. This is why I think it must be the coil. I want to check the coil and that is why I need the specks for the coil. What should it read when checking with a volt meter. Thanks Bob
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bob, I never use a multi-meter on the coil igniters, so I can't intelligently answer that part of your question. I know for certain that if you pulled the spark plug and re-connected the boot onto it, then made grounded contact on the cylinder while rotating the magneto/flywheel and got absolutely nothing with the switch in the on position, and tried once again with a known good plug same result, then the igniter is not doing it's job. it is uncommon for the coil to fail, but it does happen. the on/off switch must make a good ground but I doubt that as an issue. it is also very very unusual for that switch to fail, so I think that is a red herring as well.
replacing the coil is relatively inexpensive. in the $20 neighborhood. sorry I can't give you a # on the multi-meter, but I just never found the need to use one where this matter is concerned. try the new coil and if still no start, then let me know and I will be happy to lead you thru my routine troubleshooting which always gets results...
make certain the test is in a dark area to be sure...
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Bob,
I have Not checked the resistance on a Model 445, but most High Voltage Coils are somewhere between 2000 - 4000 (2K - 4K) ohms between the HV lead and the coil ground (Armature). Some larger engines like coils on Lawnmowers maybe 5K plus, and smaller engines less than 2K.
I would suggest disconnecting the grounding wire at the coil, and try seeing if you get a spark as Robert suggested, If the engine starts you can always pull out on the choke to shut it down, but that will eliminate any fault in the wiring or switch. Obviously If you do get a spark then you have a wire or switch problem.
One last possibility is sometimes the HV boot & connector come loose of the HV Lead, and are not making contact, as a last resort before throwing the coil away you can check that connection & the HV wire to the coil.
I hope this helps.
PS. I am Not a Husqvarna Representative or an Authorized Repair, Just an experimental chainsaw person
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I have pulled off the kill switch wire and checked the boot and connector and the leads. I installed a new spark plug and grounded it to cylinder head. Still no spark. I cannot see anything else that it could be. I am thinking it must be the coil. So the next step is to test it to see if I am getting the required ohms. Thanks for the help I will let you know what I find. .
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I am pretty sure if you just put a new coil/igniter on the saw that you will get results. no matter what resistance reading you get, it will not resurrect the dead.
good luck dude, now lets get to cutting...
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