[ChuckB]

1986 FLTC. I totally rebuilt my engine after hearing what turned out to be a worn crank pin. The bottom end had over 100K on it. At first I was going to depend on outside help, but after a situation, I decided to do it all myself. I bought most the necessary tools and working on it when I could, I had it back together. I did send the cylinders out and since the heads were recently done I only lapped the valves. Took it for a ride and was disappointed to hear a tapping noise. It would be most noticeable under a load. Believe it or not, I only put a few miles on the bike, turned around for home and tore it
completely apart again!

I did determine that it wasn't the lifters before doing so.

Well, I replaced and re-lapped/honed all the bushings again. I did reuse the left side Timken's, with the same spacer keeping the same end play. All new pins shafts roller bearings. Insanity! After a couple more years, it was done. Took it for a ride. Guess what? Same noise!

This time I just kept riding it. It bugs the heck out of me! I now have about 5000 miles on the engine since the rebuild.

I made a you tube video in hopes of figuring the noise out. Not much results.

I though I would post it here so you can take a listen. What do you think?

https://www.youtube.com/watch?v=9UZmsV5goYE

 

[ChuckB]

Sounds like lifters/pushrods to me. What lifters/pushrods are you using?

Hmmm.. ? I checked them pretty thoroughly. I even tried another set of lifters.

I am using Crane Time Saver adjustable pushrods, the same that were in there before I started working on the engine.

Question: Is this the wrong place to post this?

After all this bike is a Tour Glide.

 

[ChuckB]

Nope, fixed fairing , your at home here. The noise is hard to tell from the video. Is everything tight in the rocker box.

Yes. I have even removed the front rocker box cover and ran the engine to see if I could pinpoint the noise to there. No dice. Everything is tight. Holding my hand there with it off tells me it's not coming from there. A stethoscope is useless to me. I don't see how people swear by them.. Too much engine noise. You can't hear the forest from the trees. I installed new shafts during the "second" rebuild. I have put my hand on the front head and could not "feel" any of the tapping. Same for the push rod tubes. It seems to be coming from the front cylinder. I lapped the right side case race to within specs, and the big end bushing the same way. The only thing I didn't change on the second rebuild was the spacer between the two tapered bearings. I always wondered if excessive run out would cause this. My end play is right .003.

I also balanced the flywheels during the second build. I bumped the compression from 8.0 to 8.5 to one and am running an EV27 cam same parts from the first build with the exception of replacing the new rings just to be safe . The wrist pins were also within specs, .0008. One thing that bothered me was that the wrist pins slid in the pistons very loose. I am using keith black hypereutectic pistons and I called KB and they said this was normal, which surprised me, since I usually have to heat pistons to get the pin to go in or use a tool to do so. These were so loose that they almost can fall out.

Yes, I realize that watching a video won't tell much.. kind of like holding the phone up and asking if you can hear that. I made that video in desperation.

The bike now runs like a raped ape. It has no problem taking my friends new '14 Street Glide off the line (maybe because I go through the gears better than him) and can match him at wide open speed.

It's getting so I don't enjoy riding her due to concentrating on that noise instead of the ride. Reluctant to tear the engine apart again. I would probably jump off a bridge if the noise appeared for the third time.

My suspicions are:

Crankshaft end play (been told by others : No way!")
The before mentioned piston pin situation (was told : "This is normal.")

I will say this: The noise becomes more evident under a load.

New to the forum so I don't know if there are some real hands on motorheads here who can set me straight.

 

[ChuckB]

What lifters?
What pre-load on them?
What is the piston to cylinder wall clearence? (Those KaBoom pistons want to be very close.)
Scott

When the engine started making noise from a worn crank pin, I wasn't sure where it was coming from. In hopes of a simple fix, I replaced my S&S lifters (installed a couple years earlier) with a set of OEM ones from the dealer. The ones I took out still looked good.



Not sure what you mean by preload, but they were adjusted the "wet" method as I always have done, which was four turns down.

The piston clearance was right at .0008

 

[ChuckB]

Sounds like those bases are covered.
Wrist pin bushings/fitment in good shape?
Scott

After wasting a few sets of wrist pin bushings I got them right. That was one of the hardest parts of the build. Finally located and purchased a Ramm Jet Jig. They passed the cigarette paper test using the Jims tool. Reamed and honed them to .0008. As mentioned above, I wasn't too happy about how loose the pin fit in the piston itself. Called KB and they said it was normal. Very loose.

 

[ChuckB]

We all have to start somewhere.

who did the machine work? saving a couple bucks by disassembly & reassembly is fine,but sizing bushings,oversizing & fitting new bearing,boring & honing and any headwork should be done by someone with the experience & tooling to do a proper job

I know you mean well, and don't take this wrong, but you don't know me from Adam.

Maybe I do have the tools, and maybe I do have experience. :grin:

I built and maintain all the vintage bikes in my signature.

Certainly nothing wrong with building your own engine, at least in my world. :wink:

 

[ChuckB]

true,as long as the right tooling is used,there shouldn't be a problem,i do mean well,no put down ment.just seen a lot of guys over the years trying to save a buck and screwing everything up.(had a guy come by once,couldnt figure out where the oil consumption & noise was coming from,on his shovel heads,he put in guides and sized them with a 3/8 drill bit)

No one totally rebuilds their bottom end on their own to save money. They do it for other reasons.

I could have easily purchased a crate engine or even a good used bike for the money I spent on tooling and machinery.

 

[ChuckB]

Sounds like primary chain slap to me or an external "somethings loose" type of rattle. Sounds like a hollow tinny rattle to me. Is it possible that something external is loose & rattling? Heat shield, floor board, etc?
As you know, the taps, ticks, rattles, etc travel throughout these motors.
Lil Chief

I investigated the possibility of something being loose pretty thoroughly, and eliminated that. I am using a Hayden M6 tensioner on a newish chain. I even bought another compensator and replaced that. I haven't totally eliminated the primary though, but I kind of doubt it. The same components, other than the compensator, that I had in the bike before. The noise seems to be coming from the upper front cylinder area.

It is very hard to get it to make the noise enough to investigate while the bike is standing still, unless I really rev it. On the highway under a load is where I really hear it.

 

[ChuckB]

don't want to over think this or say you over looked something but :

valve springs and or guides

piston to valve clearance

timing

just thinking

I know that's dangerous

JtB

At first I thought it was just pinging. I tried retarding the timing just a little. I eliminated that.

The EV27 cam is suppose to bolt in, but I did bump the compression by 1/2. I just got one of those inspection scopes and plan to look down the cylinders.

I really appreciate all of y'alls input. Thanks.