When I first start the bike up she makes a low humming noise for 1-2 seconds and then stops. Is it the cam chain tensioner that I'm hearing? Or the chain itself? Thanks.

Humming noise?kinda like....HHHMMMMMMMM?"when I first start er up"...dumb question here...is this noise when you TURN THE KEY?Or after she's actually started?

Like Hub said...you KNOW what cam chain noise sounds like when you hear it...there's no getting around the fact that it sounds like something is breaking inside your motor!DEFINITELY NOT a hum my man.

* Last updated by: blue07 on 7/10/2011 @ 4:53 AM *

The noise is after I start it - not the fuel pump priming! I'm going for memory since it's been a week or two, but I'm going to guess the tensioner, already ordered one from APE just to find out. I'd rather the motor didn't break apart!

The remark about "after starting the bike" was in response to blue07's reply.

To get it straight - When I start the bike (usually when cold) I hear low hum/rattle for a second or two, definitely no more then 2 seconds. Since it had 4.5k miles on it when I bought it I figured it was normal. But since I've had some stuttering while under 4k rpm's I started to strip it down and do a complete one over on the bike. Check the valves, replace the plugs, check all vacuum lines.. Now seemed like a good time to tackle this rattle I was hearing. I don't know if it's ever been on a dyno, but I doubt it - there was no Power Commander on it and the bike is mostly stock. The only modification was the secondaries - they were removed. This week or the next I plan on yanking the throttle bodies and removing the secondaries shaft. It has too many problems from the previous owner to keep it in there (drilled holes and what not..) I'm doing all the work hoping nothing is wrong with the internals!

I suppose it COULD be cct noise.Mine clacked pretty good for a second or so.Till I got the manual tensioner.IDK.

"too many problems with the secondary shaft"...hmmmm....never heard of that before.I removed my secondaries a long time ago...the only "problem" I ever had was at the very FIRST time I started the engine after removing the plates,I coded an FI error...and there was a grinding noise for just a moment.After that...no issues at all.I'm assuming that when I removed the plates,the shaft was "resetting" on the initial startup.The code went by so quickly,if I hadn't been looking at the dash,I would have never seen it.

Honestly...IMO ONLY...I would NOT remove the throttlebodies shaft unless absolutely necessary.I guess if you're determined to ...go for it.It's a lot of work(to me anyway).This has kinda been debated....but I can't see any harm in leaving it in there?Taking it out MAY be a more "iffy" procedure-wise.It's not really designed to be removed.I mean,the Company sells the unit as a whole....not replacement parts for it(unless I'm off here).

I believe the "debate" was concerning "airflow"...well,okay.So a guy removes the shaft...fine...now he's got four barrels with two holes in their sides each....I wonder what that is gonna do for vacuum and such?IDK.

* Last updated by: blue07 on 7/10/2011 @ 11:19 AM *

My secondary shaft has multiple "gouges" where the previous owner tried drilling out the screws. While I could just fill in the holes on the shaft - I could also fill in the holes in the walls of the throttle bodies. Right now the throttle bodies are out of the bike, so either would be easy to do.

Would it be better to drill out the other screws? Make all the shafts the same? That said, if polishing the shaft if the way to go.. then I'll do that. There's a small "gouge" on the inside of the throttle body, and I do mean small. You can see it, but you can't feel it. Should I polish it down some or just leave it? Thanks for the help.