Bosch or NGK Resistor Plug

[ray benson]

I was told by a Makita service center tech in 2006 that the makita cutoff saws use a resistor plug. Using a non- resistor plug burns up the electronic ignition. He showed me 7 saws from a large contractor that all had bad ignitions. All caused by the well intentioned contractors mechanic putting in non-resistor plugs. He said if it calls for a resistor plug then use only a resistor plug.

 

[Ozhoo]

Clipped from the mother ships tech training

 

[stckciv]

Dolmar and Husqvarna have stated in the past that some cutoff saw models had coil failures due to non resistor plugs being used.

 

[blsnelling]

Why not just run what the manufacturer calls for?

IIRC, Bosch is Asian made now. I switched to NGK.

 

[Preston624]

Why not just run what the manufacturer calls for?

IIRC, Bosch is Asian made now. I switched to NGK.

Now that's the main question that I'm asking. My Stihl manual says that I can use either. Maybe I'm missing something here but, I just don't understand why I would want to use a resistor plug if I don't have. But, again maybe I'm missing something.

 

[Preston624]

With all of the help you all have given me I think that as long as the Stihl manual states that I can use either a resistor or non-resistor plug I may as well stay with a non-resistor plug in my chainsaw.

Thank you everyone for the help and suggestions. Best, Preston

 

[aokpops]

I had a lot of trouble with non resistor plugs . Went threw more coils on different engines including 4 stroke small engines . Got a little generator 4 cycle that would burn the coil out in less than a half hour . Had some would spark blue but would not run the non resistor would knock the timing in the coil off . I now check every plug with a ohm meter for small engines . I did a little cold start test on 3 defferent brands bosch champion ngk . The champion did the best .

 

[burnses]

when I fix up a saw or get a "from the dump" saw I try to run it on the plug it came with ....if it runs good and im gonna keep it or after a rebuild I run bpmr7a ngk....

 

[Little Al]

In a chainsaw or any O P E, no benefit to using a resistor plug.

Unless of course, you may have some kind of a high-end stereo mounted to it.

Got to agree with that + a resistance in the set up, lead,cap,or plug ,will load the coil more thats one of the reasons copper wire cored HT lead is specced rather than carbon core. Re post 27 never had trouble tha way around tons of problems the other way around with resister kit.

 

[super3]

Now that's the main question that I'm asking. My Stihl manual says that I can use either. Maybe I'm missing something here but, I just don't understand why I would want to use a resistor plug if I don't have. But, again maybe I'm missing something.

Both the Bosch and NGK plugs you listed in your OP are resister plugs.

 

[Preston624]

Thanks again everyone for all of the detailed information in helping me to make an informed decision. Best, Preston

 

[Robin Wood]

I was told by a Makita service center tech in 2006 that the makita cutoff saws use a resistor plug. Using a non- resistor plug burns up the electronic ignition. He showed me 7 saws from a large contractor that all had bad ignitions. All caused by the well intentioned contractors mechanic putting in non-resistor plugs. He said if it calls for a resistor plug then use only a resistor plug.

my dealer had come across couple cutter saws with bad ignitions due to using the non r spark plugs
i think cutter saws of all make are sensitive when it comes to spark plug, they've got some weird limiting ignitions
always use the resistor spark plug when the manufacturer calls for it to avoid ignitions going bust

 

[Preston624]

Sounds like good advise. Thanks.

 

[1Alpha1]

Denso is also a very good plug. It looks a lot like an NGK. Not sure if they are somehow related?