Clutch rattle

[kdxdazz]

A short video on the kips vs clutch rattle, the experienced guys will already know how to identify but worth a watch

[H Muz]

Cool, thanks for posting.

[Chuck78]

The knocking sound in neutral, without giving it any real thoughts, I'd always attributed to hot clutch swell causing slight interference in the gearbox, but actually thinking about the mechanics of it, the clutch plates swelling have absolutely nothing to do with any noises in neutral once the bike is warmed up, & that was a foolish thought.

Now I'm curious as to what this typical inherent knocking in neutral sound is caused by?
My wife's '07 KTM 200 XC-W does nearly the exact same thing as well, although it may have entirely subsided since we installed a Rekluse auto clutch in hers come to think of it, which makes perfect sense.

Is this just the thinned out hot gearbox oil not damping the vibes of the single cylinder engine as much as when cold, & the gear backlash tolerances causing the noise?
If so, I'd expect thicker viscosity gearbox oil to quiet this phenomenon, while making for more clunky less smooth shifting...

How's that theory sound?

[kdxdazz]

The knocking sound in neutral, without giving it any real thoughts, I'd always attributed to hot clutch swell causing slight interference in the gearbox, but actually thinking about the mechanics of it, the clutch plates swelling have absolutely nothing to do with any noises in neutral once the bike is warmed up, & that was a foolish thought.

Now I'm curious as to what this typical inherent knocking in neutral sound is caused by?
My wife's '07 KTM 200 XC-W does nearly the exact same thing as well, although it may have entirely subsided since we installed a Rekluse auto clutch in hers come to think of it, which makes perfect sense.

Is this just the thinned out hot gearbox oil not damping the vibes of the single cylinder engine as much as when cold, & the gear backlash tolerances causing the noise?
If so, I'd expect thicker viscosity gearbox oil to quiet this phenomenon, while making for more clunky less smooth shifting...

How's that theory sound?

I was using ATF but since switched to 10w-30 engine oil, engine is ever so slightly quieter, I don't think thinned gearbox oil is an issue, the kdx clutch is a poor, noisy design as outlined in my previous video that's why it's so easy to notch the clutch basket
I have heard somebodys theory of the clutch gear is straight cut where as other bikes are helical cut and straight cut has more backlash,I don't know if this holds weight or not

My number 1 theory at the moment to a noisy clutch in neutral is, and of course talking if the clutch is all in good working order, is poor jetting at idle, I was laughed at for this theory on the other Facebook page but of course majority of them are just clowns, but let me share my experiences. Last month I removed the lectron due to not being able to find metering rods that work here in Thailand but what it did have was the most beautiful smooth running idle, when I put my pwk back on a noticed how much noisier the clutch is, I think poor jetting at idle causes engine vibrations
My 4 stroke scooter has 150,000 klms on it and a noisy grabby clutch, the clutch is noisiest on first start up in the morning, you would think the opposite if the oil is at its thickest, but my jetting is off and it runs poorly early in the morning, the clutch noise gradually improves as the engine idle improves
Many people talk about removing the airbox lid which only makes idling a jetting worse, the exact reason enduro bikes run airbox lid and snorkel to begin with
I'm going to begin wideband 02 Sensor testing on the kdx this week then hopefully try again with the lectron and O2 sensor

I'm currently getting the jetting dialled in with the O2 sensor on my Drz but extremely difficult due to no straight roads here and looking down at the gauge while avoiding tourists and stray dogs
But that's my long answer to kdx clutch noise

[kdxdazz]

My nsr150.clutch with helical gear, over 30,000klm and near zero notches on the basket

[JimmyB]

viewtopic.php?f=77&t=26264&p=227328&hil ... le#p227328

Kdxdazz I appreciate all the effort to quieten these bikes down, I did your KIPS mod the following teardown and no more rattle, but I have been wearing ear plugs for the past 20 years due others in the group on 4-strokes so they drown out the KDX big time.

Did the modifications you did in this clutch rattle video help at all? The helical cut gears are certainly quieter and have greater contact area, I think on average the contact area on a helical cut gear is 1.5 tooth vs 1 on a straight cut gear. The straight cut transmission gears use in autos use to put out a real good whine. The helical cut gear could possibly also give a little bit of axle(side) load on the basket maybe tightening up the clearance(slop) a bit also, making it quieter??
I notice on my bike when in neutral and you pull the clutch lever the tone does change, just curious do you run a full liter/quart of tranny oil, I think Jeff Fredette use to recommend running a full liter/quart as it would quiet the clutch some, I have been running a full liter of the same oil in the KDXs since 1990, it is basically a sump/splash system so the full bottle does not hurt.
Curious if maybe a straight 30 or 40 weight motor oil might make a difference, might give that a try one day.

[kdxdazz]

viewtopic.php?f=77&t=26264&p=227328&hil ... le#p227328

Kdxdazz I appreciate all the effort to quieten these bikes down, I did your KIPS mod the following teardown and no more rattle, but I have been wearing ear plugs for the past 20 years due others in the group on 4-strokes so they drown out the KDX big time.

Did the modifications you did in this clutch rattle video help at all? The helical cut gears are certainly quieter and have greater contact area, I think on average the contact area on a helical cut gear is 1.5 tooth vs 1 on a straight cut gear. The straight cut transmission gears use in autos use to put out a real good whine. The helical cut gear could possibly also give a little bit of axle(side) load on the basket maybe tightening up the clearance(slop) a bit also, making it quieter??
I notice on my bike when in neutral and you pull the clutch lever the tone does change, just curious do you run a full liter/quart of tranny oil, I think Jeff Fredette use to recommend running a full liter/quart as it would quiet the clutch some, I have been running a full liter of the same oil in the KDXs since 1990, it is basically a sump/splash system so the full bottle does not hurt.
Curious if maybe a straight 30 or 40 weight motor oil might make a difference, might give that a try one day.
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Thankyou
I use 10w-30 motor oil now, was using ATF but feel it is a bit too thin at 7w
The kdx clutch is just not a great design in terms of how it is mounted to the input shaft, it has a bronze bush which wears out, Honda uses solid steel bushes, interestingly the nsr150 clutch plates fit the kdx.
I have no idea on the advantages or disadvantages of helical gears but I'm inclined to think they are better if Honda uses them. If straight cut gears were causing noise and backlash then I think the clutch wouldn't go quiet when pulling in the clutch
When I get chance I will analyse the kdx clutch and nsr clutch side by side and see what can be learnt,
as I'm getting older I really don't like noisy bikes, yesterday I was out on my other kdx with the stock expansion chamber and it's a pleasure to ride compared to the noisy pro circuit expansion chamber, I live in the middle of a city so not looking like a noisy idiot is important to me
Changing out the clutch plates is probably the easiest option in partially quiet down the clutch
Adding extra oil may slightly reduce noise but it's really just a band aid, I know Americans like to follow Jeff fredette but I personally haven't seen one ounce of information put out by him addressing kdx design flaws and how to fix them
I like to wear ear plugs too, in the video I forgot to wear ear plugs while testing and now my tinnitus is back

[jamiethegiraffe]

Hey Dazz, i was watching this video of yours:

and was wondering, did the stepped washer turn out to be a good fix? I've watched the part 2 video where you swage the fiber plate tangs to better fit the basket notches, but the stepped washer strikes me as a very good idea even if one were using fresh plates and a new basket.

[kdxdazz]

Hey Dazz, i was watching this video of yours:

and was wondering, did the stepped washer turn out to be a good fix? I've watched the part 2 video where you swage the fiber plate tangs to better fit the basket notches, but the stepped washer strikes me as a very good idea even if one were using fresh plates and a new basket.

The stepped washer definitely reduced the free play but how much it reduced the audible rattle I'm not quite sure as I installed new clutch plates at the same time, one person made a very good comment on here in that reducing that free play to zero would impede oil flow to the bush, the nsr clutch also uses a similar bushing system which I might try to copy as an experiment
My other kdx came with a mitaka billet clutch but it also had notches worn in to it which again I believe is because of the free play in the bush although when I filed the notches I could feel how much harder the material is compared to stock