Had my bike dynoed today.

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jmillheiser · #1 Post by **jmillheiser** » Sat May 06, 2006 4:11 pm

The local yamaha dealer was doing a special promotion today and was offering free dyno runs. I decided what the hell and had my CX500 run.

she put 32.34hp to the rear wheel at 7000rpm, the dyno tech said that it is running way rich at the top end and desperately needs to be rejetted, he said this also explains why my bike gets such crappy fuel economy at highway speeds.

the dyno graph is a nice smooth upsloping line like a v-twin is supposed to have until 7000rpm then it drops off erratically until redline, this is where is running too rich.

TheImp · #2 Post by **TheImp** » Sat May 06, 2006 4:14 pm

hmm perhaps that was why they offered free dynos, to point out less than optimal running condition on people's bikes and they may beef up their repair shop revenue. Its a pretty good business idea if that was their intention. I think many people would love to get their bikes on a dyno.

flynrider · #3 Post by **flynrider** » Sat May 06, 2006 5:23 pm

That's exactly why the offered them for free. I used to run a dyno at a friend's shop on weekends. He only charged a few bucks for a run, and when the shop business was down, they were free

It's defintely a money maker. The number one problem was improperly installed intake and exhaust mods that had the effect of reducing horsepower from stock. You can bet that someone who spent a few hundred bucks on a pipe isn't going to stand still for less than stock horsepower.

jmillheiser · #4 Post by **jmillheiser** » Sat May 06, 2006 7:07 pm

in my case im running stock intake and exhaust, and stock jetting. Problem is I live at 6000ft.

Im also not so sure its running as rich as I originally thought. I pulled my plugs and they are a nice brown color not sooty black, I also adjusted the valves tonight and in addition to quieting down a tad it seems to run a little smoother.

flynrider · #5 Post by **flynrider** » Sat May 06, 2006 7:50 pm

It might be worth checking out. If you've got sea level jets at 6,000 ft. you could definitely do better. On the other hand 32.34 hp is not too shabby for a CX500 at that altitude. If that was a reading at sea-level it would indicate a problem, but at 6,000 ft, that's close to what I'd expect to see from a CX500.

BigChickenStrips · Sat May 06, 2006 10:57 pm

a little shot of nitrous oxide every time you hit W.O.T. should clear that problem up for you.

seriously thats cool though, and maybe you an get it "fixed" and they will re-dyno it for free?

ab420 · #7 Post by **ab420** » Sun May 07, 2006 4:36 am

definitely an interesting business plan....

jmillheiser · #8 Post by **jmillheiser** » Sun May 07, 2006 5:56 am

no they wont redyno it for free, ill check out their rates though. If they are reasonable it might be worth an hour or so of dyno time to get the jetting right.