| Author | Message | ||
     Duphuckincati |
09 CR w/ 6500 miles,race ECM for Keda pipe, all great except at light or off throttle there's a clattery/rattle, sounds like from left front. Not always there but mostly, goes away on loaded throttle. Don't think it's the rotor nut but will check, seems to be louder with the race ECM. Could the matter in which it (the ECM) lightens engine breaking create a weird intake noise? Or what's the deal with the cam chain tensioners old type vs new? If this was an old Triumph it would sound like loose clattery valves. Sorta sounds like an exhaust leak but it goes away on throttle. And yes I did search for this in old threads. Any other ideas? (Message edited by duphuckincati on July 07, 2011) | ||
| Nuts4mc |
1) does it "knock" under acceleration? = cheap gas.... 2) too lean = hot exhaust valves are igniting left over charge as you roll off the throttle?...sounds like a "Jake-Brake" on a diesel truck...or a big twin with straight pipes decelerating - time to visit a dyno with an exhaust gas analyzer. 3) loose exhaust pipes at the head?- blown out exhaust packing between pipe and head...but why?....see #2 good luck | ||
| Duphuckincati |
1)Quiet under acceleration 2)Not that loud 3)See #1 But thanks for the input. | ||
| Milleniumx1 |
I'm not the type to listen for odd noises just for the hell of it ... But I too have noticed what you're describing, just in the last few weeks. I've run the E B R unit for over a year, so I don't think that's it. But I get that rattle (sounds a bit like shaking a spray paint can) on light throttle, especially from a stop. I've had a look around and can't see anything loose. And it disappears when you roll on harder. Mike | ||
| Duphuckincati |
This is loud enough to hear with a pipe and earplugs, but not so loud like you think it's about to blow up or anything. When I stop and rev the motor it's sounding fine. I don't know anything about ECM and EFI (good with Lucas and Amal though), and I just wonder if the "less/no engine braking" could be creating a different intake noise or butterfly flutter in the throttle body since (as I understand) the throttle does not close the injectors all the way. Or maybe I'm totally off base. But it is enough of a noise that i gotta wonder what's causing it. | ||
| Bueller4ever |
Sounds like pinging from your description. What octane gas do you run? maybe the tune has too much timing there and a little lean. Pinging almost never happens when free revving an engine, ime, so you would only hear it under load. | ||
| Duphuckincati |
I run whatever is the highest octane at the station I pull into, so 91+. The tune is the ebr for the Keda pipe, so I can only presume it's correct. And the noise is there only on light/steady/off throttle, and is quiet under load. But your suggestions certainly are possible. I'm thinking the Sunoco offers the highest octane? I'll seek that out. (Message edited by duphuckincati on July 07, 2011) | ||
| Zac4mac |
Cush-drive | ||
| Duphuckincati |
Care to elaborate? | ||
| Kicka666 |
Off the beaten path, cam chain tensioners are oil pressure fed, oil level is good? low oil level Rotax's rattle, they all do, RSV's to & they also burn out stators. | ||
| Duphuckincati |
Yeah, I thought about the oil level too but it's right on the money. The point that this noise happens on an easy or off load was making me wonder about the reason for the re-design of the camchain tensioners. Was there something with the old style that might make a noise? There's not much posted on here about those, so how much of a problem were/are they? | ||
| Luisemilio25r |
Check your rotor nut asap. Mine was doing that (09 CR). Took it in just in time. They did find some metal shavings on the magnet. Better safe than sorry. Unless still under factory warranty. Then just run the piss out of it and blow the engine, then get new engine  . Kidding. | ||
| Zac4mac |
Sorry Larry, it was a brainfart... no idea. Z | ||
| Duphuckincati |
Luisemilio25r, so your motor was making the rattle on light or off throttle but quiet when under load? The nut is on my mind for sure, but the manner in which the noise occurs didn't seem to add up to that. But I'll pull the cover and check, and I think I'll remove the goop that restricts oil flow too. | ||
| Luisemilio25r |
It was the most noticeable while idling. But also made quite a racket while taking off (1500 to 3000 rpm). | ||
| Milezero5 |
Without retorqing the nut, how would one say check the thing, as I dont have the locking tool yet. I have heard the same kinds of noises at times. Hopefully some go away after I change the oil, valves,etc.(Already had the cam chain guides replaced under that recall) Does it almost sound like when your too low in rpms in a higher gear when accelerating? | ||
| Duphuckincati |
Milezero5, I will try the too-low-a-gear test to see how much the noise sounds like that, sitting here at my desk I can see where that thought would occur but will try that later today. It still mostly reminded me of old Triumph clattery loose valves. (inefficient but simpler times) As far as the nut tightening goes, when/if I get to that point I was hoping to borrow/rent/buy the tool myself. I've heard from another member who has the same noise that the nut did not seem to be the case. And the cam chain deal was for bikes built earlier than mine. (Message edited by duphuckincati on July 09, 2011) (Message edited by duphuckincati on July 09, 2011) | ||
| Carbonbigfoot |
Sounds like the beginning of the rotor nut being loose. If it gets louder, that's my guess. Check it. R |
