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Has anyone experienced this? when cruising in moderately slow traffic in 3rd gear at 3000 RPM the bike's engine sounds like it has a ROD KNOCK. Makbe it is piston slap? Don't know but it is a little scary...Any other experiences like this? Also hate that serious vibration that comes on at about 3500 and stays with you when cruising at 80 or so...
 

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Got over 5,000 miles on mine. After accelerating through 2,500 rpm mine is smooth as silk from 3k up. And no hint of any untoward sounds or noises. It just acts and sounds smoother and smoother from 3k rpm up. Because I'd heard of some anomalies around 3,500 rpm, just yesterday I spent some time checking and listening for anything around that rpm range. Nothing. The bike was perfectly smooth with no different noises or any sign of a knock that I can hear.
 

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Could also be due to shifting up too soon or using a lower octane gas (don't know what you are using). Just a couple of thoughts.
 

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It's all in the game, mine does the same thing too, I had never own a V-Twin before I've only had in line fours and they are relatively quiet. At first I thought something was wrong but it's a normal characteristic of the bike. All V-Twins have their own individual noises and sounds. You're right, at first I thought I was about to throw a rod but I listened to other M109s and they all do it. Think about it this way, you have the largest pistons in any production vehicle,try slinging those puppies as this bike those and you're going to make noises too.

C-One
 

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Same thing here....around 3000k,  3500 and up...nothing but pure acceleration..:)  I have had other v-twins...heard the same. It can be very scary if you're not aware of this effect though.....
 
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ok, question. When someone says it's sounds like a "rod knock" or it sounds like it's about to "throw a rod" aren't they referring to a push rod?
 

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itsthatfast said:
OK, question. When someone says it's sounds like a "rod knock" or it sounds like it's about to "throw a rod" aren't they referring to a push rod?
Not necessarily they mean a connecting rod knock. that is the thing that connects the piston to the crank. :joke:
 
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cbxer55 said:
You dont think this engine has pushrods, do you? :eek:
I thought it had hydraulic lifters! :joke:
You know, never need to adjust them.
My ride for the last 10 years has been an in-line 6.
Whispery smooth, definitely took some getting used to the noises this beast makes.
But I have not heard anything that makes me think its broke.
If it aint broke, dont fix it. :bigthumbsup:
that's what I was getting at. I know this motor has overhead cams. So connecting rods can knock? Can someone explain how? I'd be interested in knowing. thanks.
 

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cbxer55 said:
Unless I am mistaken, the connecting rods on this bike are plain bearing. ::)
On a plain bearing the rod rides on a thin layer of oil squeezed into the bearing area under pressure.
When they wear beyond a certain point, the oil layer is not thick enough for the rod to smoothly
ride around the crank journal. Hence there is play in the bearing area causing a knocking sound.
If they were roller bearings, no pressure is required, just a spray or splash onto the bearings
will suffice.
This is why most two-strokes use roller bearings, there is no oil pressure, just splash.
When roller bearings go bad, you do not get a knock, you get a sieze, right now! Not enough
pre-mix, or the injector pump fails, SIEZE!
Motors with roller bearings generally do not have high oil pressure. Suzukis and Kawasakis
with roller bearings show little or no oil pressure at idle, and it freaks some folks, who dont
know any better, out.
It is very doubtful any of us have enough miles, or wear on our engines to have a rod knock yet.

Hope this is a good explanation for you.

Robert Hill
+1, good post. I about crapped my pants when I put an oil pressure gauge on my old Z1 900 Kawasaki. It read very little oil pressure and I did not know it had roller bearing crank bearings. got out the book and it said 3psi! Well I had every bit of that so all was good. :D
 

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cbxer55 said:
I suspect he is one who is not mechanically inclined. ::)
Or he is puttin us on. :duck:
In any event, a pushrod can knock if the valve lash is out of adjustment.
Same as valves can make ticking noises when they are out of adjustment.
When the clearance is too big, you get some ticking noise.
When the clearance is tight, it may make no noise whatsoever.
You will think everything is fine, when in fact you are burnin up your exhaust valve.
But, how many motorcycle engines use pushrods these days?
Mostly a Hardly thing.
It is a moot point here!
We got no pushrods. :bigthumbsup:
But at 14,500 miles we may have to remove our cams to set our valve lash properly. :barf:
I can do it, but aint lookin forward to it. ::)

Robert Hill
Yes I posted about the 109 valve adjust and got no responses. I was just curious who ever had hit the magic 14.5k mark had it done at the dealer or themselves whether many were off enough to have to swap shims. I would imagine the dealer gets a fair price for this especially if he has to pull the cams. To be honest the hardest part is going to be stripping the 109 down just to get to the valve covers. I would imagine if any are off it will be this first go around. on my ZRX it was that way and once they seated in there is minimal adjusting to be done. the ZRX recommends checking every 6k but I do it about every 10k and only adjust one or two just to keep them in the middle of the range. one good thing on the ZRX the cams do not come out. they use a small rocker that is spring loaded from the side to keep it on top of the valve/shim. push it out of the way and use a pencil magnet to pick them up and tweezers to place them. The chart in the service manual is real handy to determine what shim goes in to correct the clearance. surprised no one has hit 14.5k yet. :dontknow:
 
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ppridgen1 said:
well on our bike ,it would be hard to do, considering they don't have them ,due to the overhead cams!!! :joke:Don't act so perfect and be condescending to people when they post and they won't call you out either !!!! :bigthumbsup:
Perry, Perry, Perry, I know the M109R doesn't have pushrods as mentioned in a previous post of mine. I am just curious as to different engine knocks. Robert from OK explained in laymen's terms about connecting rod knocks. My second question was regarding pushrod knocking. Now that's been answered. Oh, and thanks for the advice about being condescending. I know you have some experience in this matter.
 
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ppridgen1 said:
i was referring to your always acting that way to my posts, but I apologize to you sir I was having a bad week at the time. But we'll call it even and start anew , hopefully with less animosity
I'll shake on that.
 
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