Alrighty, thought I would put this sound clip out there for others to compare their engines to. My 99 sportsman 500 is pretty loud. What do you think?
And thanks to opt in advance for any thoughts.

 

I guess this is the engine you changed the cam out on..Other than the loud exhaust, sounds like a worn/grooved front clutch spider hammering against the guides.Had em come in sounding like a diesel engine because the drive clutch was worn out,buttons worn down to nothing or even missing.You can tell by checking for deep grooves in the guide channel area where the 6 clutch buttons ride.If really grooved even with new buttons a worn out clutch can still make noise. Plus a worn cam chain can be noisy also.. Couple things to look at.

 

I hope that's the clutch making that noise or he would have very loose valves.

 

The clutch was rebuilt less than a year ago and this thing has been apart a lot in that time too. The groves were noticeably warn so that's probably some of the noise. I have her torn down now because of the oiling issue on the rebuild, and the valves were still fine. 50 hours on this build. As in another one of my threads when the new rebuild was fired up, the oil valve was stick in a way that oil would not get to the crank despite priming the line two times. So maybe a minute or so of no oil. Then 50 hours run time with oil flow and burning a lot. This is my once upon a time pretty piston.
I know that these oil pumps are known to be noisy, and when I put a screwdriver to the engine the loudest part is from the oil pump. When I got the crankcase with the new bearings closed up, I would turn the crank and get a click/tap at one spot every rotation. Any thoughts? The top end is apart so might as well make sure the bottom end isn't goin to mess up my next investment.
Thanks for the help.

 

Oil pump is a simple g rotor type that has pump rotors for oil intake and scavenge that share a basic design with a lot of other different makes and models of machines.Rotors can wear,but best to check them out.Chapter 5 (lower engine) in your manual gives you step by step on what to check in case you've over looked anything.If any click clacking that was noticed before engine was cranked would have been the best time to stop and check it out, but your down to it now. #2,3,11,12.
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I'll try and get the crank out tomorrow to further investigate.
Had a buddy come over and take some measurements today, he suspects the shop I had the boring done at set me up to tight. In addition, there is no taper I'm the cylinder. Happen to have any insight on this OPT?
Right now I don't trust the shop and am considering a new stock piston and sending the jug to get a new sleeve pressed it.

 

Here's what I came up with.

 

Misread, these are what I got. My dad won't go for the whole pump. Will try for the outer rotors at least.

 

Organized

 

If you replace rotors,replace as a complete set,not just an individual outer or an inner as they have been mated to each other after all these years. Mismatch new and old rotors and you could still end up with noise.