Spark Plug Heat Range

[smiliecoyote]

Has any one tried using the NGK DR9EA spark plug. I have to pretty much flog my bike on a large portion of my commute with plenty of near WOT operation I'm concerned the WOT may be in effect leaning me out. The DR8EA looks pretty good but shows where it may have been too hot. Will the colder plug help reduce the engine heat soak.

[JWR]

The DR8EA is better for cold weather riding.

Since you are in Texas, I would go with the 9.

Very small difference in either plug.


EPA has a lot to do with the set-up of our bikes.

[Road_Clam]

Has any one tried using the NGK DR9EA spark plug. I have to pretty much flog my bike on a large portion of my commute with plenty of near WOT operation I'm concerned the WOT may be in effect leaning me out. The DR8EA looks pretty good but shows where it may have been too hot. Will the colder plug help reduce the engine heat soak.

Swapping sparkplug heat ranges to alter "richness" or "leanness" is really not the correct way to go about correcting the problem. You really should get to the root of the problem which sounds like simply lean jetting..

[smiliecoyote]

I considered that; but then I figured for the rest of my commute, which is in the 35-45 MPH or creep and beep range, I'd be too rich. Besides that, I'm getting 81.8 MPG, I don't want to sacrafice that but running richer if I don't have to.