New plugs, synched TBs = less mpg???

Michael-NC

Registered
Changed spark plugs to iridium ones (gapped properly) and synched TBs. Checked TPS position and it is OK ("-" in the middle). Engine runs smooth, great idle, pulls strong, no complaints there. However, before plug change and TB synch I was getting 41-44mpg not pushing it, now it is 33-36mpg, same riding style, same PC3 map. It's an '03 with HMF slip-ons. Tried other maps and still ca. 8-10mpg less than before. WTF? Thanks for any advise.
 
Dang, I used to know some things you could try. Check the TB synch again, maybe? Usually, when I do all of the other things, I do the TB synch last. Also, make sure the engine is completely warmed up before synching. It can't be cold.

Also, when I synch the TB's, I check them at 2500 rpm, then again at 3500 rpm, then at 2500 rpm again. Seems to give me better results.

Let me know if that helps.

--Wag--
 
Did all that, warm engine, took my time with TB synch and did it after installing the iridiums, bike runs better than before, lower mpg is the only minus.
 
I've hear rumors of iridiums causing lower mileage. Try stockers (NGK CR9E's) and see what happens.

--Wag--
 
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