snapped rear spocket bolts!

[murphy45]

Hi Guys
Keep snapping rear spocket bolts,its breaking off the hex bolt on the swing arm side of spocket.Have checked chain tension that doesn't seem to be the problem.Only happening after getting work done on the motor.
Can anyone help!
Cheers

[Pappy]

We snapped all 4 twice!

I just drilled out the sprocket hub and used Honda bolts/nuts and a Honda rear sprocket..no more issues

[Drewltr450]

must have a beastly motor, thats wild

[MtnEX]

More likely just not keeping up with the torque on the bolts... getting loose or not properly torqued during a sprocket install... or loose chain derailing.


If you run MX or whatever, try a chain guide if you can... and CERTAINLY buy the Moose Poly case saver before this costs you your cases... and a lot of time/money to split them and transfer your goods to a new set of cases.

[Pappy]

Ours was from catching rocks on a MX track. Kawi uses the cheapest stuff on this quad, the bolts size in general makes it alot weaker then any other modern set up ive seen.

[murphy45]

yeah the bolts need to be alot stronger,I'll try drilling out the spocket hub and using a better set up
Cheers

[MtnEX]

I'll take you guy's word for it and have a look at the bolts tomorrow.... it's setting dead beside my Honda anyways.

I had just totally assumed so far that the few that did have problems had it from not checking the bolts, not properly torquing the bolts when changing gearing.... failing to run a chain guide on an MX track... using those HIGH DOLLAR sprockets...

All of the above is asking for disaster... and then there is always the misfortune of something getting caught up in the drive line.


If I had big money to throw behind it, I'd be building KFX chain guards, guides, rear protection, sprocket hubs, and air intakes.

But I don't....

[MtnEX]

Oh, and I forgot to add....

In my opinion, the KFX setup is too darn far from "concentric" and poorly guided.


What I mean is... it flat out must have excessive slack in the chain at the top and bottom of the travel in order to NOT be over-tight when all 3 center points align...

When the suspension is compressed enough that the centerline of the sprocket is aligned with the centerline of the swingarm pivot and the centerline of the rear sprocket..... Which is where I do my chain adjustments at to run close to max tension.


And when I say too far from "concentric"... what I mean is that the center of the front sprocket is too far from the center of the swingarm pivot.

My old Polaris has concentric drive, meaning the front sprocket is actually between the swingarm pivots... and centered on the same pivot point. So the chain tension/slack is pretty much constant throughout the range of the wheel travel.

[WildWestRacing]

My son Josh runs the Nationals and we had the same problem last year. We broke the sprocket bolts 3 times last year and I always keep the proper tension/slack in the chain.

After we had the sprocket hub drilled out to accommodate the Honda sprocket bolts, we have not had anymore problems.

Thanks,
Bill

[MtnEX]

Thanks for making me compare my 400EX and KFX....

1 - The Honda bolts are a bit larger...

2 - 2 out of 4 bolts on my Honda are spinning loose!!!!

[trompen542]

Originally posted by MtnEX
I'll take you guy's word for it and have a look at the bolts tomorrow.... it's setting dead beside my Honda anyways.

I had just totally assumed so far that the few that did have problems had it from not checking the bolts, not properly torquing the bolts when changing gearing.... failing to run a chain guide on an MX track... using those HIGH DOLLAR sprockets...

All of the above is asking for disaster... and then there is always the misfortune of something getting caught up in the drive line.


If I had big money to throw behind it, I'd be building KFX chain guards, guides, rear protection, sprocket hubs, and air intakes.

But I don't.... We build all of them, and they are on sale now.
KOQ racing products

[Hetrick Racing]

We run the stock bolts on some(under contract) and the Honda bolts on others.
I will say I change the stock ones very often,so the Honda bolts are a better system in time.

In my opinion, the KFX setup is too darn far from "concentric" and poorly guided.
Also though we run a 65designs chain guide for the stock swing arm it is the best

[sexysilverado45]

When you talk about drilling out and tapping them or just bolt lock washers and nuts

[hondaracer_34]

Ive replaced these bolts so many times...then when i had to replace my cases, I decided to run the Honda setup, maybe Kawasaki should take some lessons from Honda.

[WildWestRacing]

Just have them drilled out to accomadate the Honda sprocket bolts. I believe it's 8mm. No tapping required.

[sexysilverado45]

Alright sounds good then run a Honda hub

[WildWestRacing]

I'm not sure about running a Honda hub. I'm talking about drilling out your Kawasaki hub and using Honda bolts.

went to the hardwear store, got the bolts just like oem bolts, washers and locking nuts for the sprocket on my 450r, i replaced mine because they were stripped, and i didnt wanna pay so much for oem bolts, work just as good for a fraction of the cost. havent had a problem yet, and they have been on there for well over a year

[hondaracer_34]

Kawi sprocket bolts are 8mm and the honda ones are 10mm.