[QUOTE=1potter1;6257483]The pistons are'nt scorched, they are showing a carbon build up!

My builder was disgusted when he pulled these pistons. He did not say one way or the other. He had recently taken the top end apart on his H-Q 120 inch and you could still see the H-Q stamp on top of the pistons with 37k miles. He put it back together with out any new parts, convinced that it would last many more miles. I'd have to say that this was caused by a rich condition. I wish that I could have a look at the spark plugs. That would tell the story.

Come to think about it , the bike did seem to get poor gas milage. I just attributed that to it being new.

 

Interesting considering that conventional internet wisdom is that the new bikes run too lean.

 

RT. You have me thinking about it too. I rode the 07 out of the same dealer brand new. The valves pinged and it even backfired once in the first five miles. On the other hand the 2010 felt as it should brand new.

I was hoping that someone would chime in that might actually know. I'm thinking that because of the cat they can richen things up a bit and still meet epa standards but that is just a guess.

I do know one thing. I was way concerned when I saw the tops of those pistons that came out of my brand new ultra!

 

You cant make me believe those are stock pistons with a factory tune.It must have had a tune a lil (or a lot)richer than stock with out upgraded pipes and air filter!My spark plugs are whiter now than they were when HD put them in there and I have 3000 miles on it.If that engine was running that rich then the check engine light should have been on all the time.And guzzled gas!
Big Block

 

What are we saying here? Was the carbon build up caused by the engine being stock or was there a tuner installed that was not calibrated properly?

 

To help the internet speculations, I believe one of the DYNO guys on this site did mention HD was able to richen up the AFR's on the 2010 models because of the new CATS.

 

You know, now that I think about it, you may be on to something. My 2010 Limited gets around 38mpg. Doesn't ping at all, and actually runs pretty good. The built 103 in my Night Train gets around 42mpg, but it's in a 2-300 pound lighter bike. I'm thinking that the cat bikes are running a richer AFR thanks to the cats. There's no need to lean them out in order to meet the air quality standards.

That would also explain why D&D says you can change pipes and A/C on a 2010 bike without a tune.


Veeeeeeeeery interesting.

 

Big Block. These pistons came out of my brand new STOCK 2010 Ultra. Guy Dalton is the builder. Another person on the H-Q forum reported the exact same thing with his 2010 with just under 1000 miles. He is also installing a H-Q kit.

 

So why did you take apart a brand new engine?I'm guessing you want more cubic inches.
Big Block

 

I'm 58 years old. I thought this chit would have gone away by now but it has not. Gotta question the sanity of a person that spends 22k on a bike and then has has it torn down to have the motor built. The numbers that I'm hearing are 110 hp and 120 tq. Longevity, reliabilty, rideabilty, and fuel milage are also factors.

Oh well, to me I'd rather spend the $ this way than on a CVO 110". This year I will be riding the HD that I only dreamed of before.