I have a 1992 FLSTC 1340 Evo that I am currently rebuilding, again. It was my fathers and about 5 years ago the base gasket on one cylinder leaked so bad he decided to have a friend "fix" it with a new top end gasket job. It never happened. The bike sat with the heads off and no oil in the motor for that entire time until about year and a half ago I decided I'm rebuilding it myself. Needless to say, got the manual, put new base gaskets, rings, all top end gaskets, pushrods, fired it up and away I went. The initial ride was good, the second ride about 5 minutes later, I could hear a scuffing sound coming from the front of the motor, more on the right hand side I think, seemingly below the cylinder. I did the old screwdriver to ear trick and couldn't hear any problems in the cylinders. Anyways, I took the primary off and replaced the clutch, every possible seal, gasket, the compensator sprocket spring was flat so I prayed that was it, replaced it, but it wasn't. Alternator looked fine. So I took the top end apart again, ran through it, checked it, no shavings in motor, no cylinder wall damage, pistons looked good, the hole 9. Put it together, first ride, great I fixed it, second ride, same thing again. Once the bike is warmed up it seems to happen. It sounds like when you apply your front brakes and you can hear the brakes on the spinning rotor. Just a scuffing sound, no ticks, knocking, banging, a scuff is the best way I can describe it. Right now, I decided to have a mechanic change the camshaft up to an Andrews EV27, take that plastic breather out and put in a stainless steel one, put in a torrington bearing, and then replace the tappet roller wheels and axles with some crane ones. If this does not solve the problem, what do you guys suggest? The only thing I can think of is some bearing or seal, is dried out from sitting so long and I can't find it. Internally, crankshaft area, what could be in there that would cause a sound like this? How about the oil pump, I'm not sure where it is located on evo's, but sitting dry for so long could that be making this sound? I'm at a loss here and although it doesn't seem to affect the bike, I want to fix the sound before it turns into a $1000 problem. Remember I hear it in front, down low. Please give me some advice.

 

From the sound of what you are replacing, it's ALREADY a $1000 problem.

 

The way I look at it is in the end it will basically be a brand new motor. Yes I have probably invested about $1000 already. Little parts here and there though, and wrenching myself. Getting paid biweekly is whats really killing me or I would put it in a shop.

 

Are ya sure it's not just an exhaust leak?

 

um yep, pretty sure...

 

They can make a scuffing sound through the breathers.....but maybe the bike is so quiet that you can hear the pistons moving....it can happen you know!

 

You have a number of choices, I suggest. Ride it until it begins to show more serious signs of distress, when any problem will be more obvious; strip and rebuild it from the ground up; change the engine for another (reman or aftermarket). Of those, the second and third are guaranteed to be expensive, while the first may give you many years of happy riding!

In other words you may be chasing something that is either not there or very minor. Yours isn't the first post of a similar nature in recent weeks, from someone riding a bike that is fairly new to them, hearing noises they can't identify. My money is on the first option. If you can't find what needs fixing, it may not be there!

 

I have a 94 and I know what you are talking about. I have 69,000 on it and when it blows then I'll worry about it. Until then. Let the sound continue.

My personal belief. Its just the motor and that's how she works.

I actually like all the sounds I have. My 94 has more rattles than my grandkids can make with all their toys. ROFLOL!!!!

 

Please don't think im wasting your time here but.... Are you using a tallish windshield? The reason I ask is because when I fit mine, after the bike is up to running temperature the motor sounds are all amplified and reverberate off of the shield, and one of the sounds that I get is a sort of rotational/cyclical scuffing noise similar to what you describe. Overall it sounds like an industrial sowing machine.When the shield is removed the bike sounds great with only the exhaust note.
Just a thought..

 

Welcome Homie ., sounds like you now have a completely rebuilt motor with a scuffing noise coming from the front , down low .???
I can appreciate the fact that this bike was originally your Dads ride and you are trying to track down the culprit etc.
You have certinally done your best here but i suspect that the offending " scuffing " noise is more related to your front brake assy. and not the motor as
motors dont make this type of " scuffling " noise.
Check the front brake for wear or sheet metal touching the assy.?
Let us know how it goes.