I did an oil change last week. I didn't change the tappet screen (did that last July). Since then a loud bottom end ticking develops and the sound from the exhaust changes after doing 70 for about five minutes. Loses a little power too. It goes away if I pull over and let the bike idol for a minute. My oil pressure gauge reads 0 heated up and about 5 psi cold at idle. Before the oil change it was 5 heated and 10 cold. Its a 94 FLHTCU. Any suggestions on where to begin? Thanks in advance.

 

Which oil did you use?

 

and..which oil filter did you use?

 

Hopefully you didn't use syntheshit oil !!!
My bike did exactly the same thing last fall... already had plans on rebuild over the winter, hear is ONLY thing I came across...
A damaged valve seat probably from a chunk of carbon from piston top, that lobe on the cam was chipping away and the roller on that lifter was also scored up.

 

I'm no expert by far but I think I would first check if the bypass plunger has something under it holding it up letting the oil go to the main case instead of building pressure for the lifters. That's the taller plug on the oil pump top. The outside plug. There is a course spring and a metal plunger under it. Use a small magnet if needed to get the plunger out then inspect for maybe a small piece of metal or something stuck under the plunger holding it open. Its designed to allow flow to the main case after sufficient oil pressure is maintained for the lifters. If its stuck open then most of the oil will bypass to the main case by what I've read.

My next step I believe is to make certain the oil pump was primed. That is easy to do by having the check ball and the fine spring out of the oil pump, the shorter inboard plug on top of the pump beside of the bypass plunger plug I mentioned above. To do this I jack up the bike, take out the spark plugs, put the trans in 5th gear, remove the little check ball and spring from the oil pump (I used a small clean metal rod then stick a good magnet on top of it to make a longer magnet to reach the little ball), then roll the rear wheel in the direction of travel (forward) by hand while watching for oil to raise up the check ball port hole. If primed right the oil should about instantly come up the hole with just a small rotation of the rear wheel by hand. If not then I use a small syringe filled with oil to fill the port letting air bubbles out then roll the wheel again until I get flow up the port hole. Install the ball and spring then move to the plunger port and do the same thing. Then to the lifter screen port rolling the wheel looking for oil to rise up the port. Once then unhook the coil from everything so it won't get burned out then use the starter to roll the engine watching the oil pressure gauge. Mine makes about 22 lbs cold off the starter alone but I've rebuilt my oil pump and found a bad seal in it. So Idk.

The lifter screen just keeps metal out of the lifter blocks that might of come through the pump.

 

Running the Harley Davidson 20W-50 and the HD chrome oil filter. Its what I've been running in the bike since I bought it.

 

I would be worried about a lifter going out...

If you are hearing a new noise, and power changes when you hear it, you need to pull the cam cover and get your eyeballs on the lifters, the inner cam bearing and the oil pump.

You need to resolve this before you ride any more...

 

Crap. It only does it when it runs at 3000+ for a couple of minutes then returns to normal at idle. Is it safe to say its a lifter?

 

It's only losing oil pressure at or above 3k while driving ( under load) yea sounds like a lifter issue.. They're cheap enough to do any ways... What is the mileage on the motor. If over 25k. Do it. As Scott once said, "at one point in the nineties HD was recommending a service replacement of the lifters at 25k".

Could very well be collapsing at higher rpm's.

 

22k on the bike. I don't have the time or patience to deal with it right now so I dropped it off at Penngrove Motorcycle Company. Just going to let them handle it. Thanks for all the input guys. For future reference will update with a damage report.