Ok cool I'll just stick with the spring off the kacr then. The noise is super loud though, did the video I posted above work? Why would it go from no noise before the mod to super loud after? Also are you talking about loosening a manual tensioner? cause loosening the bolt on the auto wouldn't do anything, right?

And ya lol, when I realized what I had done wrong I was just like theres no way this bike is gonna start again once I fix it. Still not positive I didn't do any damage(it'd be a miracle if there wasn't any piston valve contact), but the fact that it's running is a really good sign. I just want to figure out this noise and get back to riding. From everything I know, have heard, etc it sounds like the cam chain tensioner, but due to my knowledge of everything done to the bike today I have my doubts lol.

Plan for tomorrow: full disassembly(cams out, release all pressure off the cam chain just cause, etc), put the cams back in according to the mcm, put the chain tensioner in normally, reassemble the rest, and test it. If the noise is still there then I might put the bike back to stock and try it once to make sure its nothing related to the mod and if it still makes the sound then order a manual one.

 

It sounds like the problem has been solved, but I see no response to the question regarding TDC, compression or exhaust, which are the only two possibilities in a correctly timed 4 stroke engine. If it is on compression TDC neither exhaust nor intake valves will be open, all should be closed. This can be seen if the cam cover is off the engine by looking at the cam lobes. If they are not pushing the buckets down the valve is closed. Also, if they are indeed open there should be a gap between the cam and bucket such that a feeler gage will slide in. If you are on TDC exhaust the exhaust valves will be open, the exhaust cam lobes clearly pointed down towards the crank pressing on the buckets, and no feeler gage should fit between the lobes and the buckets. Spark? I suppose that a slowly turned engine may spark but who turns by hand an engine with the ignition key turned on? I always find TDC with the plug out and a plastic straw dropped in to the piston crown so I can see the point of TDC then check on the mark.
Plan for tomorrow: full disassembly(cams out, release all pressure off the cam chain just cause, etc), put the cams back in according to the mcm, put the chain tensioner in normally, reassemble the rest, and test it. If the noise is still there then I might put the bike back to stock and try it once to make sure its nothing related to the mod and if it still makes the sound then order a manual one.
Perhaps there is someone from this forum that has experience with cam timing who could assist? Where about are you located?

 

This is true on a new engine, but.... he rotated the cams, twice! Where the cams are now is not going to tell you anything about when TDC of the compression stroke is.

The good thing is the engine ran, so maybe he is close with the cams and the noise is just the auto/manual cam tensioner. I think the auto, if you reset it is going to make quite a bit of noise until it takes up the slack, I have no info on the manual one. Not being there, my suggestion is to run it up based on snap's description, verify TDC of the compression stroke and make sure the cams are where they are suppose to be.

One has to be extremely careful when it comes to rotating the cams with the crank.

 

Ok Clay.. I did the MCM very very very carefully and slowly. And I did it correctly. However, the noise and racket upon the first startup had me thinking and doing exactly as you are now.. It sounds like the engine is going to destroy itself..

If your engine starts instantly with a push of the button, and idles correctly and in a stable fashion, you most certainly have the mod correct and without damage to the engine. Try to focus only on the cam chain tensioner. Barring some weird issue - chain guide shoes misaligned etc etc - the chain tensioner is the cure..

 

Where does the noise come from? It will be louder when closer to the source. Listen carefully and you will be able to tell.

• If the noise is from the head area on the left it is the KACR, but KLXter is right, it should not be that noisy unless the idle is really low or the shoes are stuck for some reason. That sounds like min 650 did when the idle would drop too low and the KACR was hitting the valve. It would go away with a few hundred more rpm, since the KACR works below around 600-800 rpm. The clearance is huge when it does flop around so the noise is huge.
• If the noise is more from the center cam area look for a really lose valve or possibly bent if one touched off. The clatter would be the excessive clearance.
• If the noise is from the right side it is the cam chain tensioner. My 650 would clack that loud, but not so much on the 250 although I never ran it with the tank off of it.

Is there a chance you forgot to put the spring back in the auto tensioner or could it just be that bad?

 

I'm pretty sure I did remove the cams at the exhaust stroke originally, the lobes faced in towards each other. There must have been pressure on the exhaust valves but I just didn't notice. And when I reinstalled them my timing was so far off it wasn't touching either valve. I also think that's why I might not have bent a valve. Since I installed it in such a way that when the piston was highest the cam lobes were basically pointing directly away from the valves.

The noise is absolutely louder on the right side. Is there anything I can try with the auto chain tensioner? The grooves look solid, maybe I just need to help it push out further?
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Also just did some research and the bike runs on a wasted spark system. So once the cams are out. All that matters is the crank is at TDC and you put the cams in as if it's a compression stroke(with lobes facing outward, correct?)

 

Correct. The crank and piston do not determine if they are at TDC of the compression or exhaust stroke. The cams do. The ignition is triggered by the flywheel on every revolution.

Ride on
Brewster

 

I have a DJ, stage 2 installed and the snorkle removed. Other than that the bike is stock. If I were to do the Marcello mod, would I have to undo what's been done to the carb?

 

Alright guys, here's the update. I went the ought my plan, unfortunately the WHOLE plan. Meaning I went all the way back to stock. The bike is running just like before now perfectly smooth and quietly. Really not sure what has been going on. When I can afford to have the bike down again maybe I'll take another look. I am 100% positive the mcm was performed properly the second time so not sure why the noise went away between then and going back to stock.

 

Clay, I'd guess you properly reset, installed, and adjusted the tensioner just now with the reset-to-stock..

Oldsgypsy: There is never a requirement to change ANYTHING on the KLX in preparation for, or after, the MCM. If you bike runs perfectly now, It will run perfectly after - just with a boost of power below 6.5K rpms..

But, you can add more fuel to the low/mid range to let the MCM really "shine"..