CR500AF lots of engine noise?

I have a 91 CR500 engine in a 06 CR250R chassis. It was put together by someone else and I bought it like it is now, so Idk whats all inside, but it seems to do alright. Im use to 2 strokes and am use to the feel and sound of them, but ever sense I bought this CR500AF it has made a heavy engine noise. Im talkin I can barely hear the powercore silencer because the engine noise is so loud. Is this normal? Do 500s just have a ton of engine noise, or is it time for a rebuild on that motor? If u guys need a better understanding, Ill try to upload a video with good sound quality so you can understand a little better.

video please. definitely  not good though

Is this your first CR500? they don't sound like tiddlers....

Pull the carb,intake and reed cage off.

1st, look at the piston, is it cracked/broken?

2nd, if not cracked, just grab it with your fingers and try to

rock it front to back. If it moves a bunch and has brown stains

below rings, it is time for a top end.

But it could be just your pipe bouncing around on exhaust flange.

 

 This is a link to a video, sorry if its super crappy quality. I tried several ways to upload it and this is the only way that worked.

This is the first 500 2t Iv ever had, so I cant tell if this is just normal noise they make or if its actually something wore out and/or broken inside there. Reeds are getting replaced as soon as my Boyesen rad valve comes in, and Ill check it while everythings off for the reed replacement.

 

  

 

 

Pull the carb,intake and reed cage off.

1st, look at the piston, is it cracked/broken?

2nd, if not cracked, just grab it with your fingers and try to

rock it front to back. If it moves a bunch and has brown stains

below rings, it is time for a top end.

But it could be just your pipe bouncing around on exhaust flange.

 

After a TON of research, I found that it could be that the timing could be slightly off and the piston has a little too much slack. Im gonna try and get that thing rebuilt with new bearings, cylinder plating, and a new coated top end thats fitted to the closest size. Ill try tuning the timing and carburetor, then add a flywheel weight to smooth the agressive power.

 

Ill try it and see how it works.

 

 This is a link to a video, sorry if its super crappy quality. I tried several ways to upload it and this is the only way that worked.

 

I have a 91 500 in my 02 cr250, sounds fine to me, how much did you pay for the bike?

Doesn't sound unnormal to me, but check the piston for cracks on the intake side, and also take off the ignition cover and pull the flywheel up and down and feel if there is any play. if it is, then rebuild it.

wood stove door gasket material wrapped on the ex manifold to seal that pipe and check the mounts and make sure the pipe isn't touching the frame rev it a few times when your checking it as that pipe will dance.

if its a stock 500 carb toss it in the trash and get a pwk- probably a 38mm air stryker if your scared of the power (because your thinking fly wheel weight ?) or a 39.5 pwk wakes it up considerably in the top end

Yeah, I'm going to get the cylinder replated put a new Wiseco coated piston and get a Keihin PWK air Stryker from JD jetting and see how it runs when I get it tuned. Possibly might put a thicker gasket on it and mild out the power a little so it's a little more rideable. It wears me out after about 2 laps just from numb hands and trying to hand on.

Better deals can be had on the PWK than JD Jetting.  IMO, his jet kits aren't worth the money.  I have one in my 06 YZ and I'm not convinced it did any more good than any proper jetting would have done.

CR500 jug doesn't need plating, just a decent rebore if it's worn.

Doesn't sound unnormal to me, but check the piston for cracks on the intake side, and also take off the ignition cover and pull the flywheel up and down and feel if there is any play. if it is, then rebuild it.

 Ok, good. I recently replaced the reeds and checked the piston and it suprisingly looked pretty new. Checked the flywheel, no play. Im glad its normal and nothing out of the ordanary for a 500. Running into new problems but that will be asked in a new topiced post.

I haven't had my 99 cr250 to long but does the 500 bolt into the frame or is there a lot of modification's that need to be made in order for the swap to work correctly?

1999 CR250R thank god for 2 strokes

I haven't had my 99 cr250 to long but does the 500 bolt into the frame or is there a lot of modification's that need to be made in order for the swap to work correctly?

1999 CR250R thank god for 2 strokes

 

cutting and welding required

The engine in the video sounds pretty normal to me.  Sounds just like my '87 did back when.  As long as you have checked the piston for cracks and excess slop and the flywheel for play and you find everything good.  You should be good to go.

 

I have a '99 AF project.  There is much less welding and cutting of the frame required on the '97-to-'99 frame.  You don't even have to cut the frame apart, just remove the front engine mounts and weld in new front mounts to match the 500 engine.  Oh, and cut the lower half of the x-brace out of the front of the frame so the pipe will fit.  The AF projects became more difficult when Honda went to the semi-double cradle from a full double cradle frame.  The later frames may have some handling advantages, but those can be addressed on the older frames when you pick suspension components if you care about it.

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