Originally Posted by 04fxd92

I never noticed a noisy engine and the bike ran really well. The bike has 22k. I’ll definitely be taking the cylinders and pistons into the shop to see what I need. I’m really hoping I can keep the cylinders and bore them to accommodate a 95” unless that’s what’s in it already.

Thanks for the detailed response.

Originally Posted by djl

Straight wound valve springs indicate pre '05 model and pistons do not look OEM; no coating as typical on OEM pistons. So I am thinking motor work has beed done. Looks like heat, too much timing, poor piston to cylinder fitment and/or sloppy break in; over bore and new pistons for sure. Don't think crank issue is in play but won't hurt to check runout as part of the rebuild process.

The tooling in the intake tells me the heads have been ported to some degree. Post a pic of the chambers/valves. Ported heads would also indicated a possible previous over bore so cylinders may not be reusable. LIke Dan89 says, find a competent machinist familiar with Harleys and he can sort you out on piston/cylinder requirements for the rebuild.

Originally Posted by 98hotrodfatboy

OP, When you said that on both piston the rear skirts were scored, are you saying on the exhaust side of the piston?. If so then I would think the wear being on the thrust side would indicate an improper piston fit.. I don't not see any discoloration of the piston to indicate hi temp or not enough clearance and you did not mention if the other side of the skirt had any scoring.. And yes the motor is not stock.. Send to a local machine shop to get measurements to see if cylinders are usable..

Originally Posted by Rounders

When maching shop that bored my orginal saw my second set , he just said thrust side or something. My guess is it is the downside of harley motor, and the angles. But he didn't seem surprised. had it at 34k and again at 90k, same bike. Curious what they say. Different jugs and pistons.

Though this last time I was getting skirt damage, CP pistons. I brought it back to rev perf thinking something was wrong. They offered to replate for $900. But not like you can believe the supplioer.

Originally Posted by Max Headflow

Revperf screwed up the cylinder finish.. It's one reason why CP pistons wore down. The other issue was top ring being molly filled..

Originally Posted by Rounders

I wouldn't go back to them. When I was quoted price for S&S crank to go 103, they included welding and balancing. I contacted S&S they did not agree,

For $100 more I could have got S&S cast iron kit. Instead I bored my old ones, and when the time comes, I'll bore them cheap again.

Stock ones did have that same wear.

For my riding, I can't tell difference between 95 and 98. IMO 95 is tried and true.

Originally Posted by 04fxd92

Thanks for the detailed response.

You are correct the bike is an 04 dyna. I plan to have the flywheel checked, trued, and welded. Hopefully I can reuse the cylinders. Luckily I have a shop locally who can do all the machining.