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Discussion Starter · #1 · (Edited)
The stock plug for the 08 C109r is listed as a NGK CR7EK.
When I go to my local Autozone they list a alternate Bosch Platinum +2 plug part #4303.

Has anyone tried these yet? If so what are your thoughts? ???

NGK


Bosch


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Probably doesn't mean a damned thing, but my experience with Bosch plugs (automotive,not motorcycles) was they were not very resistant to fuel fouling and once they got "wet" although they would fire they didn't hold up to high rpm loads thereafter. Personally I have never had any plug issues with NGK in automotive or motorcycle applications......and that's been for over 40 years.
 

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The stock plug for the 08 C109r is listed as a NGK CR7EK.
When I go to my local Autozone they list a alternate Bosch Platinum +2 plug part #4303.

Has anyone tried these yet? If so what are your thoughts? ???

NGK


Bosch


One issue is the gap. The NGK has a fairly narrow gap (.024-.028 according to the manual), the Bosch has a really wide gap since it's a flush center electrode style. I suspect that the gap is probably double that of the NGK.

The coils on the 109 probably weren't designed to bridge such a large gap and intermittent firing might be the result.
 

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Discussion Starter · #6 ·
thanks everyone.

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if you got an O'reillys nearby, price them (NGK's) there, they had the best price when I changed my plugs. They had to order them but had em a day later from the warehouse
 
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