Camshaft Top End Rattle

Carbtune Test

I just whacked my carbtune on and came up with these results.





Thoughts!!!!!!!!!!!!!

Any chance of recording the sound, Don?

I did Mark,on post #238. Let me know whay tou think.

Any chance of recording the sound, Don?

You can certainly synch carbs without motor being hot. It may not be perfect, but I doubt it will be that far off.

Sorry to hear the problem hasn't been resolved. My 650 has tick at idle that I have almost given up caring about. Doesn't happen all the time nor does it sound quite as steady as yours.

I know you haven't driven it too much since the tear down, but did the air jets seem to help?

Hi Ed, initially on startup it was popping in the exhaust when I revved it in the shed, but i only ran it for two minutes. I took it out yesterday and when it was warmed up it was idling fine and there was no hesitation or lag between the different stages of throttle openings. Very happy with the power and will check the spark plugs after a longer run when they have had time to get a bit of colour.

You can certainly synch carbs without motor being hot. It may not be perfect, but I doubt it will be that far off.

Sorry to hear the problem hasn't been resolved. My 650 has tick at idle that I have almost given up caring about. Doesn't happen all the time nor does it sound quite as steady as yours.

I know you haven't driven it too much since the tear down, but did the air jets seem to help?

Thanks guys. I will try those ideas as well as synching the carbs. Can I check the synch on the carbs without warming the motor just to get a rough idea how far out they are from each other. You see it's raing here and not expected to stop for a few days.

I have tried the stethescope ideas but cannot really localise the noise to any particular spot, it seems to be everywhere. Although I am not so sure it's coming from the top end now, it sounds more around the clutch housing area. But hard to tell.

[tkent02]

Ride it until it goes bang.... I bet we'll find the problem at that stage

That will be a long ride, methinks.

[salty_monk]

Ride it until it goes bang.... I bet we'll find the problem at that stage

Very frustrating!

Good luck Don

[tkent02]

Does it sound the same with or without the clutch lever pulled in? How about with the clutch in idling in gear? Is this the same bottom end engine you had in the bike before the 650 mod? If so was it silent then? Have you listened with a stethoscope of some sort to determine better where the sound is coming from? One more thing I would try is to assemble the valve cover without the rubber half moons and chrome covers, see if pushing in the end of the cam shafts as it idles changes the noise at all. Push with a nylon tipped tool or something, not sure quite what.

[Nessism]

Sorry to hear the noise isn't gone Don. Good thing that bike isn't mine since it would have been over some cliff by now if it was.

Can think of only two things: the engagement of the clutch and crank gear is messed up somehow as evidenced with the contact pattern being offset, or that hole in the cylinder wall is causing the noise. How about selectively pulling off spark plug caps to deactivate each cylinder while taking note of any changes to the noise? Try to figure out if the noise is occurring with the same frequency as the crank, or if it's 1/2 or what? If the cylinder with the hole is causing the noise the engine should sound different with that spark plug pulled off I think.

Sorry I can't offer anything more specific.

Ed

[salty_monk]

Nothing touching the frame is there? One of my bikes used to touch the coils to the tank underside unless I mounted the tank in a particular way...

Thanks Pete for the encoragement. I will persevere.

[pete]

You know Don my 450 used to make a noise similar somewhat to what I can hear in your video there, and it was just the noise the exhaust made at idle, that was it, rev it and gone. Drop the idle and gone.

I think it was because the baffles were rusting and the pipes were rusting.

I must say though that that was back in, well... late 90's when I discovered that and figured it out, so my memory is a little foggy and it's a little hard to tell from the video.

However, congrats again on getting it complete and running, it does sound good to my ears and is makin' me a little jealous and impatient for mine to be running again.

I wonder if your carbs are out of sync enough to make the noise. Try syncing the carbs and see if the noise goes away.

Yes that is my next move. I have the carbtune setup, but have never used it before. I have to set it up first, I think I have to cut some tubes and insert in the lengths of rubber pipes. I need to get the instructions out and read them to see what to do.

I wonder if your carbs are out of sync enough to make the noise. Try syncing the carbs and see if the noise goes away.