02 night train, 25-30k miles started knocking one day then quickly advanced to an awful banging noise, sounds like its coming from the front cylinder so i first assumed a bent valve, but I can't be sure. I took the engine down to the cylinders and noticed a lot of carbon, I assumed the noise was detonation, cleaned everything up, nothing looked bent or torn up, reassembled, started it again and the noise is still there. Now my best guess is maybe a lifter collapsed and it's just slamming against the pushrod, also I can smell a faint burning smell coming from the intake. Before I take the engine apart again, does anyone have any suggestions on where or what to look at?

Ps...about 25-30k miles

 

Service manual

 

been here a long while and am still waiting to see a helpful comment from purpledouche. I looked all through the manual, and for the life of me, I cant find the section that tells you how to fix a "banging" noise in your engine. Since the OP tore down the top end, perhaps he has a manual and cant find that section either. Just sayin

 

DG, you're gonna wait a long time. You should soak your vagina in warm water, seems to be hurt.

 

If you get some trash in a lifter and it bleeds down it will make a terrible banging in the head. That is what I would check. However unless it just sounded like it was going to blow up I would have let it idle and put a stethoscope on it to determine as well as possible were the noise was coming from. If it is a lifter it will be a clatter up in the head. When you pull the lifters pull the oil pump and check to see where trash came from.

 

I tried listening with a screwdriver but that noise is making my butthole pucker so I don't want to let it idle, If a lifter just all out goes bad is it possible to be more than a ticking? I've never actually heard a bad lifter before, but just have been told its a ticking...this is more of a gremlin with a hammer inside there.

 

A while back I went into my primary looking again why it was so noisy. I was way past oil change time and I also drained the oil. I cranked the engine manually a lot trying using a dial indicator checking run out in the primary indexing sprockets and did not think about no oil in it and collapsed the lifters. When I got it all together and started it I heard two gremlins with hammers smashing each others toes. I just knew it was going to break something before it got pumped up. It took probably 30 seconds. Never going to do that again. The rockers are up in the aluminum heads and they are like loudspeaker. If it happened all at once either something broke or it's a lifter. If you have to use a screw driver, put an ear plug in your other ear. Really a sorry substitute for a stethoscope

 

Cam chain tensioners?

 

Cam chain tensioners is where I would look first also. Do you still have oil pressure? Sometimes trash from the bad tensioners goes to the oil pump, and shears the key. Or maybe just plugged up the screen to the lifters. Might check the screen to the lifters first to see if there is any blockage there.

 

Aftermarket gear driven cams, and fueling cam plate, and fueling oil pump, this is my cousins bike and apparently he had a catastrophic bearing failure, he paid a shop to put a bunch of aftermarket components in it, this was 5-6 years ago though. So probably a good idea here would be to first remove the lifters and see if any gunky nasty bits got into them?