FMF Gnarly woods vs FMF Gnarly desert pipe

[NZ500]

Hey guys.

I'm looking at doing some mods to my kx500 for a big beach racing event (Burt Munro Chellenge) in a few months. The race is on a flat beach, half a mile each way with a u-turn at each end. The main race is 50 laps.

Currently my engine is stock (about 3 hours on complete rebuild) with a standard Gnarly pipe (looks like a stock one) and new Pro Circuit 304 stainless muffler. I'm looking at buying a Gnarly Desert pipe while the exchange rate is so good. Would it make a significant difference on my flat out, top gear beach race? Or do I keep my pipe and lug more gearing with the torque of the current pipe? I'll be getting a Vforce3 and Wiseco piston (to be ported) at the same time. Gearing I currently have is 15/42. Bike has standard compression (although fresh) and running 105 octane leaded avgas.

The reason why I say the FMF gnarly desert pipe is because it seems to be the only readily available, new top end pipe?

There is a practice race so I'll take a 16 tooth sprocket too if I think it can lug it. I think there will be serious arse pucker when that's wide open though haha.

[alward25]

That sounds like a fun race!!!  Lots of back and forth,  but wide out running!!!  The FMF is a great pipe,  the Pro circuit P2 is a great pipe too. Either would be a great choice.  Good luck,  don't forget to post some pics and jet up to comp for the WOT running!!!


Alex

[sniper1]

         The gnarly is a low end pipe and my bike had stock reeds with platinum pipe when I got it so I put a gnarly pipe on it with moose read spacer (spacer installed for mid to top so I put it between reed cage and carb not against intake) and I installed the boyeson pro series carbon fiber reeds in the stock reed cage with stock reed stops.

http://www.jcmotors.com/p-3649-fmf-gnarly-2-stroke-exhaust-pipe-kawasaki-kx500-88-04-desert-pipe.aspx

         It really woke the bike up and with the proper jetting (previous owner had it very rich) the throttle response is fantastic I always knew when my 500s were running right when I could just putt along in 1st 2nd or 3rd and twist the throttle and the bike revs instantly with no hesitation or sputter it just revs and goes.

         Before the mods and proper jetting the bike was slow to respond and didn't have the arm stretching pull I wanted in mid to top end and I really can't say which mods did what since I changed everything at once to include taking the carb apart and cleaning it real good and setting my float level but I really like the combo.

         So the gnarly is going to give you more low end grunt and the boyeson reeds give better throttle response then the moose spacer gives more mid to top where I have it installed but I figured with the gnarly pipe I had all the low end that I would need and I'm glad I went the route that I did.

        I would love to see the rad valve and v-force compared to the stock reed cage with the boyeson carbon fiber pro reeds to see which one is making more power and at what rpm because I have had rad valves in my previous k5s and wasn't all that happy with it's performance so that just leaves the v-force that I haven't ever owned but you might want to try the boyeson pro reeds with stock cage and stops with moose spacer and gnarly just to see where you are at and it's only $50 delivered for the reeds instead of $170 for the v-force.

        I'll be honest with you, this bike pulls extremely hard out of the hole and I can't imagine being any happier with the way it pulls through the mid range to top end it's just a lot of fun to ride.

http://compare.ebay.com/like/290485474026?var=lv&ltyp=AllFixedPriceItemTypes&var=sbar&_lwgsi=y

[Kiwi500]

Hi

I've done a couple of beach races in Gisborne, same deal 800m point to point track.
I bought my 500 from Gissy and it was raced on the beach for a bit of it's life.
It has a Gnarly pipe on it, but unsure of model (woods or desert)
I ran 15/38 last time out and it goes like a scalded cat. (170Km +)
Tried 16/38 but 5th was no good(no acceleration)
Barrel has been ported in the past by somone.
Might have to go to the Gill for the burt munro racing on year ! Still got family down there.
Cheers Grant