Engine problem, need ideas

Long story short, It looks like I may heave screwed something up in my kawi 250 by redlining it (briefly) a few times after it was warmed (8 mile ride) - needed to see the readouts on the stupid digital tach I installed that wasn’t reading high rpms correctly. When I started it up afterwords (going back from work) the engine sounded different, there is a lot more noise from the motor, a sort of continuos clatter like really loud valves. It got louder as I increased the rpms as well, to the point that I can hear it while riding and it’s a lot louder than the motor itself - a loud buzz/clatter. No loss of power though, and I didn’t see any oil in the coolant, the oil levels also look normal. Noise seems to be coming from the top end and more to the left side. Anyone have any ideas? I was going to remove the valve cover and see if anything may have gone loose up in there.

Could have starved the lifters of oil some how.

if i remember right the cams in these bikes were soft ,ya might have wasted a lobe or pitted it

Any way to inspect for it without taking the whole motor apart?
I was going to change the oil today to check for any debris in it and look under the valve cover, maybe check the camchain tensioner - I don’t know if it can suddenly go bad like that but the symptoms are similar.

Would that be visible without valve cover or would I need to take them out for a closer look? I just need some ideas on how to go about this.

pull the cover ,ya should be able to see the lobes and the shims .droppin the oil and filtering it would be a good start to see if any metal is in there

Whew, looks like I got really lucky.
Alright, so I get new oil, warm it up and change it. Strained it to be sure, no shavings, bits, nothing. Pulled the valve cover, again, didn’t see anything out of the ordinary. Decided to poke around just in case, and sure enough, one of hard-to-see exhaust tappet bolts look a little longer than it should. On closer look the locknut on it is missing. At this point I’m feeling a bit of premonitory dread. Look around carefully and there it is, laying near the valve well. With a little sweating and some magnet on screwdriver and some wire hook improv I managed to get it back on but I don’t have any tools to adjust it and the rocker is pretty loose, along with a couple others. Put everything back together and start it up and there is definitely less noise. So, it was loose valves (they usually get tighter on these bikes, my butched attempt at adjusting last year might have something to do with this) and it needs a valve adjustment asap. This nut must have been going loose slowly and redlining finally knocked it off the bolt. I think I need a beer.

good for you ,now go get some feeler gauges and adjust yourself

I’ve got the gauges, the problem is it needs a special tool (like a socket through which you can insert the screwdriver to adjust the bolts) and some of them are really hard to get at. I might try it if I can get the tool, but it might be safer to just let someone more qualified handle this.

open end wrench and small screwdriver ,all i ever used

Was going to ask when was the last time you have the valves adjusted.

In this case an openend won’t work, it needs a long 1/4 socket I believe.
The one here is the intake, they are “easy” to get to compared to the exhaust one which are right next to engine wall (angled towards it as well) and about 2 inches lower.

go to sears and get a nut driver ,that the tube is hollow on ,would make quick work of that …or get one from snap on but they are big monaey threw them

I tried doing them last summer but could get to some of them - exhaust ones need the tool or a small long socket. The clearances checked and locknuts looked tight so I left it at that. Definitely gotta do it now though.

yeah ,

Took me 3 hours yesterday but it’s working great now.
All the intake were tight and exhaust way loose.
Hardly hear the valves now and the throttle response got much better.
All that’s left is to sync the carbs.

Good too hear! :thumbup

Eh, now I’ve got another problem.
Went for a long ride today (only rode it about 15 miles since the adjustment), and by about 20 miles later the throttle started getting all choppy in the midrange. It got worse as I got home. Didn’t look like anything is stuck in the fuel filter, could it be the valves went our of adjustment? I cranked those nuts down pretty good, and the manual specifies only 14 ft/lbs. It was running fine after the adjustment until the end of the that second long ride, and the valve noise seems to be the same.
Valves, crap in the fuel, carbs badly out of sync?
What could cause choppy throttle?

Took it for a quick spin again, still the same problem, it gets very choppy but completely intermittently, can’t really pinpoint it to anything specific. I guess it’s not overheating. Battery going bad maybe? The tach was acting a little more erratic as well, hmm…

if it was mechanical it would be constant “internal motor anyway” could be plugs coil anything ign related or fuel related …the valves good for tightening on those so i would recheck that

Turned out to be a loose battery terminal, should have checked that first.
Everything has been working fine now for a couple days.