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[Slopokes72]

I am in the process of having some motor work done to my '13 CVO Ultra and was able to get a couple pics of my pistons while the jugs and heads are off.  My question is what is "normal" carbon build up on top of pistons.  My motor has 15K miles and a mild cam installed and SERT tune.  I was just curiuos and looking for feedback from someone other than the HD dealer mechanics.  Please look at the pics and give your opinion.  Thanks

[Slopokes72]

here is a closer pic

[HILLSIDECYCLE.COM]

Probably oil coming in thru the emmission-breathers if at all oily, if dry/soot then a rich/overfueled condition.
Scott

[CVO2FIXUP]

 More interested in the blow by on the side of the piston and around the rings.  In the firs pick looks like the skirt is gouged badly.  If there is lots blow by, its a condition that needs to be rectified. 

[HD Street Performance]

Yes there is blow by. The piston shows signs

[HILLSIDECYCLE.COM]

A leakdown test prior to teardown would have given a heads-up.
Scott

[North Star]

[North Star]

[North Star]

Those were my pistons at 30,000 miles- it's a wonder the bike even ran as good as it did.

My builder blames full synthetic oil being used from day 1- it will get into the combustion chambers with the high heat and out of round cylinders. He only recommends dino or semi-synthetic, which is what I'm now running.

Not anecdotal or internet info here- he has built over 30 110's, and all had some excessive carbon build up, but apparently I won the prize for the worst he's seen.

 

[Slopokes72]

Ok how is that fixed and should I be looking at cylinder walls as well. My cylinders are getting diamond cut out of state. Heads are getting port and polish work. New high compression pistons are going back in when reassembled.

[lilcoot]

My pistons at 11000 miles.  '12 CVO SG.  Burned a lot of oil.  North Star, another member here (Vanamal) had pistons that looked worse, IMHO.  Harley should be ashamed of their poor quality.

[touareg]

I had the same problem, happend after the recal for the 2007 cvo's. In few hondred km it burned all the oil in the carter. The Moco refused to fix it even though it was still on waranty. They blamed it on the Thundermax I had on it, had to pay 1400 €.

[HD Street Performance]

Not taking any sides but the 110 is a pressure cooker, by design. The pistons and cylinders are very high quality. Lean mixtures, heat, retarded spark, high cylinder pressure, and high ambient temperatures all add up to an imminent failure.
I have used the Mahle pistons both in 110 and 113 .060 os twin cams with success but those were properly broken in and tuned. Overly rich is just as bad as lean whatever the tuning device is.
I have attached a 113 for reference, conservative compression optimized for touring 10.4:1 tman 577 cams.

[HILLSIDECYCLE.COM]

My pistons at 11000 miles.  '12 CVO SG.  Burned a lot of oil.  North Star, another member here (Vanamal) had pistons that looked worse, IMHO.  Harley should be ashamed of their poor quality.

I'd suspect that piston pic showns signs of oil being baked on via mist thru the breathers.
Scott

[touareg]

I must have been very clouded in my motor, cause it baked alot of it on the pistons and heads.