Rod knock or KIPS?

[ballsymcgee]

Just bought a 2004 KDX 200. I genuinely cant tell if this is rod knock or KIPS is loud as hell.

[bufftester]

That doesn't sound like KIPS to me.

[John_S]

That’s how my 220 sounded when I bought it. Yours seemed to go away completely when you gassed it. Mine was still there from idle to about 2000-2500 rpms. I put one of those mechanics stethoscopes on it and it wasn’t coming from the KIPS. A new piston and rings and it went away. It was piston slap. Sounded just like yours and I’m so glad it was an easy fix.

I would look at doing the top end right away even if it didn’t make that noise. There’s no telling how many hours are on that piston. If the cylinder isn’t scored you’re looking at about 150 in parts from RMATV. That $17 Tusk top end gasket set is a winner.

[ballsymcgee]

That’s how my 220 sounded when I bought it. Yours seemed to go away completely when you gassed it. Mine was still there from idle to about 2000-2500 rpms. I put one of those mechanics stethoscopes on it and it wasn’t coming from the KIPS. A new piston and rings and it went away. It was piston slap. Sounded just like yours and I’m so glad it was an easy fix.

I would look at doing the top end right away even if it didn’t make that noise. There’s no telling how many hours are on that piston. If the cylinder isn’t scored you’re looking at about 150 in parts from RMATV. That $17 Tusk top end gasket set is a winner.

Way ahead of you, been taking apart the bike day by day because its getting way too hot by the time I get home from work here. Anyone have access to a PDF of the service manual for the 04? I can only find one from 94 on google.

[KDXGarage]

Welcome to kdxrider.net.

Good luck on the rebuild. That's a mighty loud rattle.

Please do not post links or request links to be posted for manuals that are copyrighted. The site does not want to be involved in any possible issues. Check out cyclepedia. They make a great manual.

Thank you.

[ballsymcgee]

Noted

[SS109]

Wow, that is loud! I would agree it doesn't sound like the KIPS and would probably be something mechanical like piston slap. Get it apart and we'll try to help you figure it out.

[kdxsully]

At first I was gonna say bottom end but when you revved it it seemed to go away. I’m in inclined to agree with the others. Take note of whether the cylinder is sleeved, that could be part of the issue if it’s worn. I doubt it’s sleeved though

[ballsymcgee]

Took it apart, done a lot a photos and videos for y'all

[ballsymcgee]

And here's photos of the cylinder

https://imgur.com/a/Nd27p2j

[ballsymcgee]

And another video

[kdxdazz]

Only sure way is to use feeler gauges and check the cylinder to piston clearance. Moving the piston in the cylinder is not accurate as the noise would be the skirt against the cylinder not the top of the piston against the cylinder. If all checks out then most likely kips. Mine had an awful knock and I fixed it, don't let anybody tell you the kips rattle is normal

[ballsymcgee]

Only sure way is to use feeler gauges and check the cylinder to piston clearance. Moving the piston in the cylinder is not accurate as the noise would be the skirt against the cylinder not the top of the piston against the cylinder. If all checks out then most likely kips. Mine had an awful knock and I fixed it, don't let anybody tell you the kips rattle is normal

How did you fix it? A new top end?

[doakley]

Based solely on your video, my vote goes to piston slap. It's a new-to-you bike so first rule is to pull the top end anyway to be sure of what you bought.

[kdxsully]

The cylinder looks good, the rod looked good. If you have a feeler gauge check the ring end gap of the piston rings in the cylinder (at bottom, middle and top). Might as well replace the rings since you have it apart. Or the whole piston kit. Was the compression really good?

Kdxzazz could be right too.

[kdxdazz]

Only sure way is to use feeler gauges and check the cylinder to piston clearance. Moving the piston in the cylinder is not accurate as the noise would be the skirt against the cylinder not the top of the piston against the cylinder. If all checks out then most likely kips. Mine had an awful knock and I fixed it, don't let anybody tell you the kips rattle is normal

How did you fix it? A new top end?

Nope. Machined up some parts and pins that were worn. Oversized ball bearing on the spring a, a peice of copper behind the main power valve to take up the slack caused by wear, few other things. I wish I would have documented the whole thing and taken photos and done a write up

[ballsymcgee]

Also forgot to add when I was taking off the shaft lever nut with the left hand threads, the nut was on so tight that I jumped teeth on the main shaft and rotated the shaft lever. So basically I rotated the shaft lever without loosening the nut. Is that catastrophic?

[SS109]

From that first vid, it is most definitely piston slap. I know a piston being able to rock that much at the top is waaaaay out of spec. Also, that piston looks hammered. There are very clear signs of a lot of wear on the one skirt that I could see in your video. Cylinder plating looks to be pretty worn as well IMO. The crosshatching that is visible is only in the areas that the rings don't touch. You can also clearly see where the rings would stop their travel down the cylinder indicating a lot of wear. IMO, it's due for a replate but that's just me. To be sure, clean it up with a Scotchbrite pad and then post up the pics of what it looks like after.

On your last post, yeah, you probably bent or broke the pin that engages the KIPS governor. You'll need to pull the engine side cover to make sure.

[bufftester]

If you rotated the pawl towards the back of the bike then you were turning the wrong way (left hand loosens clockwise). Do you have a manual? It clearly shows how to support that pawl to prevent just that occurence. Regardless, you will need to pull the right side cover and check the governor. Looks like a replate and fresh top end is in order.

[ballsymcgee]

If you rotated the pawl towards the back of the bike then you were turning the wrong way (left hand loosens clockwise). Do you have a manual? It clearly shows how to support that pawl to prevent just that occurence. Regardless, you will need to pull the right side cover and check the governor. Looks like a replate and fresh top end is in order.

Manual I have didn't say anything about supporting the pawl. But that's my lesson learned either way. Definitely getting it replated, have a top end ordered.