New plugs, synched TBs = less mpg???

[Michael-NC]

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.

 

[Wag]

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--

 

[Michael-NC]

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.

 

[Big Red]

All hoses hooked up?

 

[Michael-NC]

yes, all hoses and sensors connected 100%

 

[Wag]

I've hear rumors of iridiums causing lower mileage. Try stockers (NGK CR9E's) and see what happens.

--Wag--