So my 23 Lowrider ST 117 has noisy valves and I don't know if it's normal. It has about 6500 miles but it's been doing it since I had it. What I'm talking about is like lugging the engine, when it's working too hard... But it's not. I'm talking between 2500-3000 rpm. I generally don't like being below 2K. Yes I'm on the throttle, but that is getting in the meat of the power band.... But valve clatter. Goes away above 3000. And I would say it's generally after the motor is warm, not just starting out.

Is this normal? I know many complain of ticking, but this isn't a "tick".

 

What gear are you in when this occurs? Sounds like detonation.

 

What grade fuel are you using?
Check for codes.
Check connections to knock sensors and temp sensors.

Still under warranty if you can duplicate the knock for the dealer have them look into it.

 

It can be any gear... It's RPM and getting on it. It could be 3/4/5... When you ask... It's not 1st. 2nd not so much.

I have never had any codes. I do have a service manual, I'll check knock sensors. I never really thought of knocking cause I've never had to deal with it on anything. Other than noise, what other signs would I have if it was knocking?

I have always used 91/premium. It is under warranty. I haven't changed anything just trying to make sure I don't nerd it. If I took it in, I would definitely have to pay attention to how exactly it is repeatable, even if I have to ride around to heat it up to duplicate. But it is definitely repeatable.

 

If you are getting on throttle in the upper gears at 2500 rpms, you are lugging the motor. The M8 is a high compression motor, combine that with summer heat, excessive load from lugging and the noise you are hearing is likely detonation. Have you tried down shifting when the ping starts to see if it goes away?

Don't disagree with CoolBreeze's comments but if you are lugging the motor and you are not the first; it's an easy fix; downshift.

 

Concur, sweet spot for my trike is cruising at 3000 rpms, I shift at around 4000 rpm when going through the gears, no pinging/detonation. I think the trike is geared a little lower than the 2 wheeler's so as Djl says try winding the gears out more and shifting around 4000 - 5000 rpm. If you are in a higher gear and get on the throttle below 3000 rpm you may get some valve clatter/detonation.

 

So generally... Just cruising around, I don't like being below 2K. And I'm not getting on it if I'm doing that... And if I do, I will certainly down shift. But you are telling me, I'm lugging the engine, gunning it square in the middle of the RPM range? 2500-3000? I have noticed it seems most prevalent around 2700.

If I am going hard thru the gears, I will shift upper 3000s. I don't find much use to be more than 4000, I can just feel if fall off after that. 4500 isn't end of the world. I have hit Rev limiter not trying. But generally 4k is my shift point. I don't find a lot of use in the 4ks. If I am not cruising, in the twisties, I find it much more useful being in the lower to mid 3000s. For acceleration and braking. So that is where I try to stay. But just cruising down the road... I'm in that 2500-3000.

So that is generally how I am riding... And I am a noob... To riding and Harleys. It could certainly be me. If it is, and with a hot engine, and I want to grab a fist full of throttle, I can't be below 3000k... Well then I need to down shift. I just thought I was in a pretty safe place, and I wasn't in low RPMs. Again, it sort of seemed like I'm lugging the engine, I just didn't believe it being in the middle of the RPM range.

 

Just to confirm it’s detonation, and just for troubleshooting, you might consider using some octane booster and see if the noise improves.

 

That's easy with a small tank. The highest around here is 91. I know in Texas you can get 96...what would be good to shoot for to know?

 

Install Adjustable Rocker Arms like in this thread https://www.hdforums.com/forum/milwa...e-rockers.html