Author Topic: Autolite Bosch Denso Champion NGK etc  (Read 1702 times)

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Offline Cut4fun .

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Autolite Bosch Denso Champion NGK etc
« on: September 23, 2012, 05:59:20 pm »
Back in June 2012 I had trouble with a like new NGK plug (more on that one below). Well today Sept 23 2012 another newer NGK plug failed in a partner 5000 of mine and showed the same symptoms  I had in my  362xp except 5000 would just pop crackle and shut off.


Start run like normal, fast idle and all. Snap the throttle let it idle and pop like a back fire and shut off. Tried several different carb settings on L side and idle screw and always ended up the same.  Popped like a back fire and off dead.

I checked flywheel, coil gap and tightness of both. I knew it had a brand new hardly used NGK BPMR4A in it after complete rebuild with new crank etc so I left it in.  I then pulled zama carb and went through it, I couldnt see anything wrong. I pulled a walbro off the shelf and put a kit in it. Installed walbro and had same issue. So that ruled out carb in my pea brain.

I'll let you guess where I went next if you want.  Then I'll tell you what it was, I think with no repeat issues so far.


While looking at saw after carb switch and testing. I decided to remove the like new NGK plug and look at the exhaust side bore etc. When putting it back  I put a Bosch WS5E in. Fired up and ran fine with walbro I just put on it too.

Turns out it was the NGK plug had went bad. It would restart and all.  It would run under load and WOT. It just wouldnt idle, it would pop once and dead shut off. 



Checked it again today. Flawless. Amazing a new plug like NGK went sour that quick.  Guess thats why I buy Bosch.  ;D

Am I the only one out there having troubles with NGK plugs?   

I've only been buying Bosch since and will avoid NGK at all cost now.
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Offline 660magnum

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Re: Spark Plug
« Reply #1 on: September 23, 2012, 07:04:13 pm »
The correct NGK Plug for most chainsaws is the BPMR7A

Maybe it fouled?

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Offline Cut4fun .

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Re: Sparkplug
« Reply #2 on: September 23, 2012, 07:31:32 pm »
Saw was just setting since our 3 cube testing. Ran fine then if you remember and has just set till today. 

Same way the plug in 362 did. Set a while and when I got it to use the plug was bad.


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Offline 660magnum

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Spark Plug Gap
« Reply #3 on: September 23, 2012, 08:03:08 pm »
The standard spark plug gap for most chainsaws now days  is .5mm or .020".

I'm around a lot of model airplane gasoline engines and they mostly run a crank triggered, battery powered, CD ignition.

With the model airplane engines pulling a propeller, they are flown around at partial throttle most of the time. There's a tuning problem that occurs whereby if you have the idle, acceleration, and high speed mixture set correctly, they burble and sputter at partial throttle settings as the engine is not pulling hard and it is more or less like running the Chainsaw out of the wood.

Most new model airplane engines use the NGK CM6 spark plug from the Honda Generators. But the older ones use the BPMR6F tapered seat and BPMR7A gasket spark plugs. Everyone uses a shielded cap and wire so the caps have to match the spark plug being used including the tiny 1/4-32 plugs. I have found that you can interchange the corresponding tapered seat and gasket plugs in the same head with no problem.

People have found that to set the plug gap at .6mm or .024", the partial throttle burble problem is diminished somewhat.

Now these engines are running a battery powered ignition - not flywheel magnetos - so they have a hot spark at idle speed.

So this may not work as well on chainsaws and weed whackers? I have not tried it on my Chainsaws yet.


















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Offline Cut4fun

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Re: Spark Plugs
« Reply #4 on: December 02, 2012, 02:49:23 pm »
Basic info on reading spark plugs.   http://www.dansmc.com/Spark_Plugs/Spark_Plugs_catalog.html


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Offline davbell22602

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Spark Plugs
« Reply #5 on: December 15, 2012, 08:08:15 pm »
Is Stens the only distributor for Torch Spark plugs? Who else sells them besides sellers on ebay?

How sells the bosch spark plugs that resasonable priced that one could resell to local local customers. Napa can get the Bosch but not at very price to resell.


Offline 660magnum

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Re: Spark Plugs
« Reply #6 on: December 15, 2012, 08:51:14 pm »
Bosch WSR5F will fit all the big plug applications it is the same as the NGK BPMR6A or Champion RCJ7Y
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Offline davbell22602

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Re: Spark Plugs
« Reply #7 on: December 15, 2012, 08:56:11 pm »
Bosch WSR5F will fit all the big plug applications it is the same as the NGK BPMR6A or Champion RCJ7Y

Thanks didnt know that.  I know HS8E, HS7E, HS5E will fit some of the smaller applications. I had better luck with the Bosch in the 2 cycle chainsaws and trimmers than the other brands. I also noticed a little power gain on the Bosch to compared Champion.

Offline Cut4fun .

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Re: Spark Plugs
« Reply #8 on: December 15, 2012, 09:07:46 pm »
I buy bosch in bulk and 10 packs and it comes out to about $1.79 a piece I think.
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Offline davbell22602

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Re: Spark Plugs
« Reply #9 on: December 15, 2012, 09:17:42 pm »
I buy bosch in bulk and 10 packs and it comes out to about $1.79 a piece I think.

Thats what paid for 24 pack of Autolite 458 from Napa. I think if I remember right I paid $38 for 20 bosch plugs from Napa.

 

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