Hello, I have an 06 Ninja 250f6f, i'm new to riding, and hoping I can get some help diagnosing a problem.
A couple weeks ago, I noticed a slight clicking at idle and when the engine and wind noise isnt too high. I thought for sure it was the valves, so I took her apart, checked everything and every valve was equally in spec.
When I put everything back together, I remembered I was running lean, because I didn't have a gasket between my stock pipe and exhaust system. I put that shim-type gasket in there, and started driving around.
Now i'm worried because about a day later, I heard a slight whirr/tickie-grind at 5k, then a day later, a sound as if cast-aluminum was being grinded (the noise that your cyclinder head makes when you slide it across the concrete) at 6.5k I torqued everything to the right setting, but I'm thinking it could be my clutch, cam, tranny, or clutch basket. if anyone needs more info, lemme know

noises are coming from mid-engine (no idea what side)

 

Use a big screwdriver as a stethescope to try and pin down where the noise is coming from. Anything posted here atm is only going to be a guess.

I'm a bit worried that you can describe the sound of a cylinder head sliding across concrete. That's a sound I've never heard.

Rob

 

lol, when i took my cylynder head cover off of my bike, and i set it on the ground, i slid it about 6 inches to sit back down.

 

Welcome and....I'm confused..

 

wow, as mentioned try and see exactly the noise is coming from. You have had the top end apart, verified valves, double check the cam chain tension now. Good luck

 

found out it was the cam chain tensioner. on my ride home from the shop... cam chain broke. should i be looking to buy a new engine or a new cam chain?

 

the engine may still be salavagable, check the valves and pistons for signs of impact, and if the valves and all other bits are still true it should fire right up with a new chain...if your lucky. If your not so lucky it can be very difficult to find what parts are damaged and what is salvagable, thankfully I'm not speaking from experience. Let us know how it goes

 

As above. Take the head off and see if there's any damage. If there isn't, and you're omfortable stripping the engine to fit a new cam chain, so that. If there's damage, or you need a shop to do the strip and rebuild, it might be cheaper to look for a used but running engine. Is it a Morse chain in this engine?

Rob

 

Back in the day (somewhere around 1979) I had a Honda CB 450 that had a cam chain tensioner back off and grind right through the motor. A little marine tex and it was good to go.

 

turns out, i found my valves and a few chunks of piston in my oil well and jammed in my clutch basket. Who knew this could happen on a 250 at 11800! I ordered a new engine and its on its way haha!