Hey guys, new member here. Experienced dirtbike and atv mechanic that's been building MX motors for years. Had an 02 954 come into the shop for a noise. This thing starts and sounds great at an idle. Actually it sounds great right up to 3000RPM which then it produces a noise. it sounds like an extreme valve noise. My first suspect was a broken valve spring but the more I think upon that i think it would be noisy at an idle too. I pulled the valve cover (which I quickly figured out wasn't an easy task lol) Rotated the motor and all looks as it should be up there. Im wondering if we have a rod that's about to make its daylight debut? Any input on common mechanical issues with these motors would be appreciated. Thanks!!!

 

Have you tried compression test? and welcome to the forum

 

Not yet. that's going to be my next step. I forgot to add to the original post also that the bike already has a manual CCT in it that ive adjusted on some. I know that always seems to be the first culprit with any of these style motors but I have already ruled that one out.

 

Had a 954 myself, must agree they all make a noise till warm , but not usually above 3000rpm,how do the plug look , thinking pre detonation ?

 

Plugs don't look bad, a little black. Nothing really out of the ordinary and they are all consistant. This is a fairly loud noise, a little too loud for detonation I believe. and the noise stays with the bike everywhere above 3k. nothing eliminates the noise other than coming back to an idle.

 

Could you record it and send it via You Tube or something alike?

 

Ive got the valve cover off it now, Once I check a few more things out I will throw the cover back on it and get ya a video!!

 

Cheers matey

 

I joined just to state I believe I have the exact same sound, it's almost like a tick? I have the noise.

Definitely not a rod.


is the sound I have, you can hear a slight tick.. i've been told it';s normal.. I just don't recall hearing it.