Bruno, when you say the screws on the bottom of the boom I am not sure what you
are referring to. The only screws I have on the bottom of the boom is the one to
attached the reflector and since the boom is one solid piece I don't see how
tighten that one can do anything. I've tighten the two on top with the black
knobs as tight as I can.

Thanks, Dom.


--- In KMXKartsowners@yahoogroups.com, Bruno <bsantos@...> wrote:
>
> On Wed, Sep 23, 2009 at 2:03 PM, Dominic <dmorellonh@...> wrote:
> >
> >
> >
> > I was rummaging through the old threads and came across this one which I
found interesting becuase on my ride yesterday my boom creeped in a bitbit. I
thought it might be because the chain is too tight and when I shift in to the
high gears it puts too much stress on the boom. My did come with a plastic
insert alread in the boom, it has a lip that fits around the edge of the boom. I
also have one of those grey square thingines and I didn't know what it was for.
After reading this I went down and tried to slip a piece of the plastic thing
into the boom but no luck. If I have to do that I will have to disassemble the
front end and then re-assemble it. Is it worth it or should I try lengthing the
chain first and see what happens?
>
> Hey Dom,
>
> You can check if the chain is too tight by shifting to both larger
> cogs front and back and check if the rear deraileur becomes
> horizontal. Move the rear deraileur from cog to cog upwards with the
> chain in the larger chainring and if it becomes horizontal at any
> point you may need to increase the lenght of the chain. If you don't
> use those combinations you can keep the chain shorter. It will last
> less than if it is longer, since there are less pieces in the chain to
> wear out, but it will maintain more tension in the chain when you ride
> on the smaller cogs making it jump less with bumps.
>
> From my experience when you ride harder, the boom can slip inside the
> frame if the screws that lock it in place aren't well tightened. You
> have to tighten both those black knobs that hold the boom and the
> screws under the frame will also do that job. So tighten both if you
> won't be adjusting the boom when riding (to let someone try it out).
>
> Do some videos of your rides if you can. :-)
>
> Cheers!
>