About_Time wrote:
It sounds to me like the cause of your engine knock may simply be the fact that you are lugging the motor.

Last year, when I first got my RoadStar, I thought that, since this is a large displacement V-Twin, the last thing it wants me to do is over-rev it. As a result it would knock from time to time down in the really low rev range especially if I put in under load.

After joining this forum I came to learn that these engines are actually happier if you keep the revs up. I have a tach on mine and routinely run it anywhere from 2500 - 3000 rpm just cruising. I won't even touch 5th gear until just about 70mph. They also suggest bumping the rev limiter every now and again, although I don't do that too often.

Anyway, keep the rpm's up a bit from where you have been would be my suggestion...your engine will thank you

Good luck

+1. Mine only knocked bad when I was lugging the motor. imo anything under about 1800 rpm is lugging.

javawave wrote:
About_Time wrote:
It sounds to me like the cause of your engine knock may simply be the fact that you are lugging the motor.

Last year, when I first got my RoadStar, I thought that, since this is a large displacement V-Twin, the last thing it wants me to do is over-rev it. As a result it would knock from time to time down in the really low rev range especially if I put in under load.

After joining this forum I came to learn that these engines are actually happier if you keep the revs up. I have a tach on mine and routinely run it anywhere from 2500 - 3000 rpm just cruising. I won't even touch 5th gear until just about 70mph. They also suggest bumping the rev limiter every now and again, although I don't do that too often.

Anyway, keep the rpm's up a bit from where you have been would be my suggestion...your engine will thank you

Good luck

+1. Mine only knocked bad when I was lugging the motor. imo anything under about 1800 rpm is lugging.

1800 ain't too bad, I keep finding conversations on it and they seem to be sold on anything under 2500 is lugging it...who knows, I don't know enough about engines to have a valid veiw point, so I just have to listen to people who know

Give yourself a little credit Jona, it's not just engines!

I question what your hearing and calling a knock, folks loose me right away when they cant tell the difference between predetination or PINGING (a low octane high comp problem) and a bearing knock on the crank journal it could just as well be piston slap, if your not familiar with engine sounds (bad ones) then you could be mistaken. Cams and their gears transfer cases, Drive belts, and hub dampers can all be suspect also as can a well tuned motor making a good torque thump.

Also do a search of topics Bottom end failures are ultra ultra rare.

+1 on lugging the motor. If my Roadie has a knocking sound, it's when I'm shifting too early. I have learned my bike is happier revving a little.

There is a slight piston slap knock that is normal of these bikes under load. Both of mine do it, and I know it's normal for these motors. If that's all it is, don't give it another thought. The bores are ceramic, and they're not being hurt by it in the slightest.

first determine what's knocking that your hearing.

Questcap wrote:
There is a slight piston slap knock that is normal of these bikes under load. Both of mine do it, and I know it's normal for these motors. If that's all it is, don't give it another thought. The bores are ceramic, and they're not being hurt by it in the slightest.
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Yup,2x that one!

My o6 that just turned 11k miles make all the noises being desribed here,just makes more noise when its really hot out and you also running at lower rpm like 2k-2200 then load the motor /accell esp when you lightly add throttle when cruising,it will really rattle & knock when i do that

Also,anything under 2k rpm is lugging it esp when under a load when accell or going up a hill i find 2k rpm is as low as these motor want to be anmd even then its laboring and is muyach happier at 2,300-2,400rpm in that case.

But when your up to spseed and crusing on lvl ground being at 2,100-2,200 rpm is just fine,i only cruise at 2k rpm like when in a lower gear like 3rd or 4th in slow but steady moving traffic.

A good shift point for consertvative riding is 2500-2,800rpm & 3k for little more agrssive riding,. Or hit the dang revlimiter for guys that want to have some fun on a 1700 with 4,700-4,800 rpm stock limiter ,1600 was i think a whimpy 4,200 or 4,400rpm for stock limiter,that was just nuts.

Scott

Thanks to everyone for your replies. I use the term knock but I could also call it a rattle. It seems to me to be predetonation due to advanced timing. But this guess is based on other (older) vehicles I have worked on in the past.

It very well could be the normal noises that these engines make as many have mentioned. I definitely don't think it's a serious problem such as a bearing etc. I would, however, like to eliminate other possibilites before living with noise. Some say they haven't noticed the noise in their bikes. This is definitely noticeable and just seems that it shouldn't be that noticable.

I was hoping there would be some way to retard the timing temporarily to see if it made any difference. There was mention of the Dyna 3000. Although I'm sure no mods have been made to the engine, I would be interested in the Dyna 3000 if retarding the timing would help reduce the noise. The price wouldn't be an issue if it worked. This is why I would like to test retarding the timing temporarily. It doesn't sound like it's possible But I'm still holding out hope. BTW, I am running 91 octane.

I'm considering taking it to another dealer to have service check it out. I'm not sure I trust them 100%. It seems they always find something to fix even though it doesn't resolve the problem.

Thanks for all your replies.

dave

I have an 05 and it developed the "KNOCK" as well. I've had it to the dealers a couple of times and they assure me there is nothing to worry about. I have also researched it as much as possible and always find the same answer, "its normal". So now I just ignore it and ride the piss out of it.