Those listings Curt supplied are for the 1700s. (Plugs DPR7EIX-9)

What plug is needed for the 1600 *?

Rayjay the 1600 take the same plug as the 1700 so use that number and your good to go.

I wondered about these at my last change. I will make the switch with all the kudos mentioned here at next change. Running regular NGKs right now. Get @ 42MPG now. Hope I see your mileage Curt. Thanks!

Gracias Curt.

Well I finished my first tank of in town riding AND I am getting about 2 to 3 mpg better mileage than I did with standard plugs. I figure if the are good for 60000 miles and I drive 30000 in town and 30000 highway I will save $370 with gas at $2.50. If the last 80000 miles then I will save $488. Think I really like these plugs and it is hard to keep from twisting because it runs so much better.

Great to hear. Got mine today FedEx from Florida. Couldn't get them around here because you have to use the stock number not the plug number - NGK Stock Number 7803

I was going to put them into the new heads when I get done doing the hi-velocity porting on them, but now I think I will do it tomorrow.

BTW - Does anyone know where to buy head-related gaskets on the cheap??

Curt, I like the math Never thought of it that way. But, and this is good news, i had my 1st set in for 13000 miles and they came out almost as good as they went in. And that was the set that went through the SVS, intake leak and the rebuild because of all that. They got cleaned with a torch twice.

So I think it's better than we think. On my second set now. 4K on them already.

Well, after the part store(orileys)ordered the wrong plugs ,i finally got mine in. When i took the other ones out, the two front ones looked great. The two back ones were blacker than coal. I just changed them this past fall. Normal? Seems to idle a bit better. gonna change oil today. So i should gat longer life frome these plugs? Hope so for what i had to pay for them. Will these help whatever is turning the back plugs black?

Cruizin said: Will these help whatever is turning the back plugs black?

They may help. Does your exhaust sound good or does it have a variation in sound, like one cylinder is hitting harder?

Check for SVS with the tissue test on the exhaust pipe, check for an intake leak at the rear (although a leak would cause a lean condition), and check for an exhaust leak at the heads.
EDIT: Also trim the choke knob to make sure it seats all the way.

If you are OK with these tests, blow some carb cleaner or Sea Foam through the carb when she's running and warmed up good. You may want to consider tuning your carb set-up if you haven't already.

[I read in the articles concerning carb tuning, etc. in the Tech Section, that checking plugs is not an accurate way to determine how the engine is running or what's wrong with it (although we all do it).]

With the lower compression engines and low octane gasoline (with 10% alcohol mixed in) the result is poor combustion. This leaves deposits of black soot on everything from the cylinder/piston head to the tail pipe.

I have a set of heads off a scoot that had only 2000 miles on her and they were SOOTY & BLACK in the combustion chambers and the right side intake valves were COATED with gunk in both cylinders.

Go figure.

i know this is an old thread, but what was the gap you guy's used on the iridium plugs for the R*? i think the manual says .034, is it diferent with the iridium's? ol girl is a '07 1700

thanks