LawnBoy Duraforce Electrical Problems

[calvin1]

I'm having what I'm thinking is a no-spark issue with my new to me duraforce powered lawnboy. It will either start on the first pull or not at all. Usually when it doesn't start I just put it back and try the next day but if I grouse and bang it will sometimes fire eventually and blow blue smoke which makes me pretty sure it's not a fuel issue.

I took the cowl off today and realised that whoever had the coil off last didn't gap it at all. I gapped it to spec but that didn't change anything. The spark plug is brand new and correctly gapped. I probed from the spark lead to the base of the plug (plug lead off the plug so the circuit is through the plug wire, coil, coil grounds, block and back to the plug base) and got 1200 Ohms. I also made sure the shorting wire is opening with the bail and it is.

Does that 1200 ohm reading sound okay?
Is there any other diagnostics I can do without throwing parts at it?

 

[dave123]

They are known to eat coil's same symptoms I had a year ago went from hard start to no start. New coil cleared that up tech said they have done pleanty over the years. I replaced my own but I remember the coil not to be cheap.

 

[calvin1]

Originally Posted By: dave123
They are known to eat coil's same symptoms I had a year ago went from hard start to no start. New coil cleared that up tech said they have done pleanty over the years. I replaced my own but I remember the coil not to be cheap.
yeah, I guess it's just wishful thinking that I won't have to replace it. The coil on my 4hp LB that I just retired only has maybe 100 hours on it but I don't think they'll interchange.

 

[Best F100]

Before you go out and buy a new coil, many guys have had sucess baking their coils (no joke). Google "Baking Lawn Boy coils."

I think the recipe is 200F for 20 minutes. It is not a permanent fix, but it works in many cases short term.

 

[calvin1]

Originally Posted By: Best F100
Before you go out and buy a new coil, many guys have had sucess baking their coils (no joke). Google "Baking Lawn Boy coils."

I think the recipe is 200F for 20 minutes. It is not a permanent fix, but it works in many cases short term.
Thanks for the tip. I tried it and the mower fired up afterwards. The coil case had a few cracks in it which I covered with liquid tape. Hopefully this will get me through the season but even if not at least I've confirmed the diagnosis. BTW, the coil has 10-99 printed on the bottom next to the part number. I'm guessing that means October, 1999 since the mower was sold in 2000. If the coil is 11 years old I guess I shouldn't feel too bad about needing a new one.

Thanks to both of you for your suggestions.

 

[mrsilv04]

I always keep a known good used coil for my 2 cycle Lawn Boys.

One benefit is the same coil fits both mowers.

 

[super20dan]

this is very common on duraforce- toro cganged vendors but the quality did not improve

 

[Panzerman]

You can buy aftermarket ones on Ebay, for about half the price of a factory one. Since the factory ones are garbage, I thought I would try a aftermarket one and its been working perfect for the last six months.

 

[andyd]

Good thought P man. Electricals are pretty much a c*r*a*pshoot now-a-daze.

 

[chewy781]

I baked the coil on my duraforce lawn mower for one hour at 200- 225F and it works flawlessly do far.

 

[super20dan]

but for how long? they usually fail soon afyer the baking. its not worth the trouble to replace it -just buy a new one.

 

[calvin1]

finally broke down and bought a new coil - $45 from a local ope dealer