I was trying to wait until it turned 100k miles but I've been hearing too much piston slap before the engine get to full temp and decided it was time. 96200 miles. Last weekend I installed an Andrews EV13 cam with new lifters and pushrods. Lifters were in pretty good shape yet but the stock cam had bad pitting on one lobe. Pulled top end off tonight. Cylinder bores are tapered .003" on the front and almost .004" on the rear. Visual blow by in the bores. A little scuffing on the EX side cylinder wall. Front piston to cylinder clearance was .004" on the front at the worst spot and .0055" on the rear. All 4 front studs are installed with shoulder up. I've always been taught on any other brand motorcycle that the shoulder goes against the cases. The manual also shows them down. When I had the rear cylinder off almost 2 years ago, 3 were also shoulder up. I installed them shoulder down. Should I just leave the fronts alone? They have made it this far.

 

the lifter rollers are shot as well its all high carbon steel and its also pitted - install new lifters or you will be back in an a short while again

leave the studs alone just clean the threads real well with a brass brush keeping the block covered

you can not check EVO cylinders with out torque plates installed as they bend all over the place when off the bike or torque plates - they have a memory its called and grow with the engine heat and return to the torqued spot when cold

the breather valve if its plastic throw it away - i never re use them as i have taken flatheads apart 60 years old and the block was perfect - put a metal one in if the bore is nice and smooth if not have it bored .030 and get the oversize valve OR use the S&S reed breather valve i like that one all my stuff has that in it -- johnjzjz

 

Tonight it will run again. Jugs were bored .010" over. Replaced both EX valves. All the seats needed some attention. Decided to install new studs. Once I pulled the front studs I found that 2 had been repaired before. Cometic gaskets. Got both heads torqued down last night. Just need to button everything up.

 

That's good to hear, almost getting 100,000 out of your 1994 ultra. I have the same year ultra with 24,000 on it, but it has the scream eagle heads cam ignition and so on. Bought it that way about 6 years ago. Blow a head gasket on it last year. but I got it fixed. On the cylinder studs I heard HD started to do shoulder down in about 1994 to stop with the base cylinder gasket leaking problem they had. It's suppose to help them for leaking. Take a look at this article below.

 

The studs were just installed upside down, period. Also I think they should be thicker and stronger. They are pretty wimpy. After doing this rebuild I can see why there are so many cases of blown gaskets and pulled studs. The parts HD used are marginal at best.

 

Yes I think they should be thicker. If you over torque them you can stretch the stud. I use new one every time.

 

Not the case! Having rebuilt various brands of engines, long 'thin' studs are a deliberate and engineered feature. Evos are fine when stock or close to stock, it is tuning and messing with them that causes problems!

 

as you stated the thin studs are deliberate and they in fact stretch when the proper torque is applied

Reason - the evo engine grows around .060 of an inch from cold to total warm up - so does the inner and outer primarys making the primary chain tighten actually as they with the motor trans and primarys heat to operating temps

 

I have heard that many times before thus keeping it pretty much stockish, except for the drop in cam. I have thicker studs on my ZRX Kaw engine. It is water cooled though so maybe there isn't as much material expansion. Weird thing I noticed is that all the studs that pulled on this engine were on the right side next to the push rods. It fired right up tonight. Exhaust has a noticeable more crisp sound. Let it idle until warm and called it a night. Twisted off one of the banjo bolts so will have to see if I can find one tomorrow.