Anyone have the same issue. Bike runs great. Rear plug slightly more gray. Can the rear cylinder run richer?

 

What model, any mods, did you have it tuned...?

 

You are running too lean. What mods have you done to your bike.

 

16 RGU. VH power duals / OS slipons / high volume HD intake / FP3. No stage one download. VH customer service said not necessary.

 

"plug reading" went out with carbs and points ignitions- there is nothing a plug would indicate to a rider which would not be obvious in another way.
modern ignition, fuel delivery and additive packages make that practice obsolete.
so don;t get hung up on the plugs.

2.) the fuel pak settings are to compensate for your parts changes- a 'download' would be counter-productive- it would be like a car with 2 steering wheels...the devices would fight each other.

the rear cylinder can run richer- and that depends on the setting of the FP3 and or the ECM- more likely the rear cylinder ignition timing is usually a couple or a few degrees less advanced than the front- that is because the rear does not get cooled as well as the front cylinder.

as for discolouring- what are you seeing?

a common mistake is to not clean the pipes enough after installing...any greasy hand prints, oils or other marrs will burn onto the chrome.

the V&H power duals connect, so your left pipe is not the rear cyl, the right is not the front- combined gasses flow thru both sides

mike

 

Am I understanding? You have an FP3 and customer service told you not to use it to tune your bike?

 

fp3 is one thing

download is another.

mike

 

I haven't used the fp3 but it flashes your ecm with a canned map that Vance and Hines provides based on your mods. They have many maps for all kinds of combo's that they generate on a dyno. Soo most of the time, no further adjustments are needed. Fp3 also has an autotune option in the rare case it's needed to fine tune your bike. Hope this helps. You are much further down the road to worry about Harley downloads and dyno tuning. If V&H did the install on your exhaust with the fp3, talk to them about the discoloration.

 

Thanks for the reply guys. Just to be clear, the discoloration is in the exhaust tip end....the left side is like 5 times darker than the right which stays clean.
I didn't do a stage one download from HD when I added the air intake and exhaust. I was told by VH that the FP3 will correct the ECM for this setup.
I'm not sure with fooling with the mixture control on the FP3...when I call VH customer service maybe they can direct me.

 

If I am understanding you correctly, the left exhaust tip end has more carbon build-up than the right, the muffler body is not discolored.


If that's the case then the left side may be running rich. You should be able to compensate for it with the FP3 by leaning out the mixture on the rear cylinder.