2008 XT250 Noise - Valves?

I've only got 200 miles on the new bike, but I notice a lot louder clattering noise when accelerating. I was afraid it was valves, but the Yamaha service manager test rode it and thought it was panels vibrating and not engine noise. I haven't been able to isolate it and am still concerned about whether its the valves, etc. It all sounds normal at lower rpm or lighter throttle.

Anyone else noticed this on the new 250?

Over here in the UK with our Jap import XT250's some of us have noticed a sort of knock, it seems to be usual, Yamaha have put some foam into the panels, I can only think it is to reduce the noise, I have also seen pics of airfilter with foam to jam it in its groove.

It seems as the bikes keep getting quieter the more engine noise and other noises we hear.

Spooky?

Cigar Mike

Hi hakai,

the only odd noise mine makes is the 'ticking' sound from the exhaust during cooling down!

I reckon that Cigar's hit the nail on the head, as you can hardly hear my 250 running, when my dad's 225 version's running!

OK thanks. Sounds like my situation isn't common. You're right that otherwise the bike is very quiet-running. But this knocking sound when accelerating doubles the noise. I suspect its the inner black panels - I'll try duct taping them and stuffing in some foam to see if I can isolate it.

I have noticed a similar noise under acceleration with my XT250. I have about 250 miles on it and it has made the noise since 0 miles. It seems to be when the engine is under load, like accelerating. I am thinking that the exhaust is so quiet and a bit restrictive, that it just causes it to sound like that. I am not too concerned about it.

Ed

Ed - sounds similar to mine, also since miles 0 to 200, and only under load. Your exhaust theory seems as good as any. If it isn't loose vibrating panels and isn't maladjusted valves or some other defect, I'll be glad to live with it.

I have been reading these posts all weekend. But because i was out of town and on the blackberry I didn't take the time until now to comment. I'll tell you what I think it is. My wife has the 06 225 and I ahve the 06 KLX 250S and on both bikes if you are in lets say 2nd or 3rd, or really any gear, except 1st, and you are under a load, the engine can start to knock. I know it sounds too simple, but keep the rpm's up a bit and don't be afraid to run it up before you shift. I have heard knocking on both bikes, and then I realized that I was in too high or low whatever its called. But it basically means in the wrong gear under a load under the right rpm range. If that makes sense. Give it a try and see what happens.