To All:

This past week, I installed the following on my 2007 Roadstar Silverado:

2.2 Ohm Dyna Coils with Magnecor KV85 Wires (Using Instructions from this site)

Dyna 3000 Ignition Module, set to 5K Rev RPM and 34A Peformance Setting,(Using Instructions from this site)

Barons Big Air Kit

Hard Krome 3" Res Tech Pipes

Combo of Barons and Dynojet Jet Kits>> Main Jet now = 172.5, Dynojet Needle at #4 Spacer, and new Dynojet Pilot Jet.(Using many articles and suggestions from this site)

After being able to ride her this weekend and evaluate her performance, it seems she has a rough idle, can't really put my finger on it, she doesn't sound right. Upper RPM's and gears she runs awesome. Also when starting her up cold, I get a slight "POP" or backfire before she starts up. When I start her, I pull the choke all the way out and hit the start button. I do not touch the throttle during start up. The PMS is at three turns, do i need to adjust this further? Up or Down? Any ideas? Maybe choke half way? Other than this, she is running and sounding awesome.

Thanks,

Are you sure the 172.5 is the right main?

If the main is OK and the "POP" is in the exhaust then try turning the PMS in 1/8 turn at a time.

Doc

In most cases the pilot jet does not need to be changed. As far as the DJ pilot, I have no idea if it is leaner or richer than stock. Your needle setting is a bit richer than most, and it would be equal to 4.5 with a Barons needle. The Dj needle is a half step richer compared to the Barons since it is shorter by the thickness of 1 washer. I wouldn't rely on sound since you just did all this work, it is going to sound a bit difference compared to how it was set-up. Without having done an AFR, mpg's to some extent will tell you if you are too rich or too lean. A good solid hwy ride(100 miles) between 60 to 70 (MIkuni uses 65mph for mileage runs), should yield around 50mpg, I find going over 70mph starts to eat the gas, city should be low 40's. Also you need to judge performance when the engine is fully warmed, you might just need to adjust the idle adjustment, again, only adjust when engine is warm. Don't keep the choke on for too long, it can and will foul plugs. This time of year, I keep mine on for about a mile, then feather the throttle if and when necessary to keep the bike idled.

Should I drop my main jet to a 167.5 or 170? I have gone through two tanks of gas and realized that my mileage is lower per gallon (Approximztely 125 miles to low gas light.) If Iam going to readjust the PMS, I should change the main jet at the same time. According to the Jetting article I should start with 167.5 and keep the 170 handy. Is this the way I should go??

Thanks

You can either re-jet according to our suggested starting setting or change out

one

thing at a time. Don't go widely changing out a bunch of stuff at once as you'll have no reference point.

When you change out the main, you need to verify that it the correct size. This is done through the WOT test.

Then you move onto the needle and PMS.

Doc

Yes One thing at a time. I will change my main jet to a 167.5 first and see how she goes. I will WOT, but I need to adjust the needle to 5th slot to WOT correct?

Yes ... that will dial out the effects of the needle.

Doc

Thanks Doc, I will do it tomorrow and let you know how it turns out. BTW after reading some old posts about oil levels, I realize that putting in the recommended amount of 4.33 qts is no longer valid. It is now 3 quarts and 12 ounces. Have you heard of this? What kind of problems will I see with too much oil??? I will fix this also.

Thanks for all your advice...

OK Here is an Update and a note of Thanks to DOC and others who made the correct suggestions. I rejetted the bike with a Mikuni (Barons) 170 Main Jet and did the WOT Test (Needle on spacer 5)and she passed the WOT Test with flying colors. I also let out the PMS by a 1/4 of a turn. The backfire on start up is gone and she idles nice and smooth. I put the needle back to the 4th slot and now all is well, she Idles good, awesome power in the lower gears and I can feel her accelerate at 80 going to 90 mph. She is sweet. If I meet any of you in person, beers are on me. This site is awesome. Another satisfied customer....and now a do it your selfer.

Thanks one and All.....