wooohooo just got confirmation email that my Dyno Jet kit is on its way to me :D :D :D :D :D :D :D 3rd gear wheelies here we come :twisted:

Hello, I'm AleX and I'm clueless about Dyno Jet Kits. Care to explain how it benefits your motorcycle?

A "jet kit" changes out the jet needles in your carbs to allow more gas to flow into the chamber for combustion. To meet EPA guidelines all bikes come "lean" off the floor. This means the mixture of gas to air isn't optimum for performance. If you up the gas to correct the mixture, you get better performance, the engine will run cooler, heat up quicker (maybe those two don't seem like they'd mix but they do), and a few other benefits. The problem is an "one size fits all" approach doesn't always work. The density of the air (high/low altitude), humidity, and the temperature of your location can affect your proper mixture. If you really want your kitten purring right the best way is to get a shop with a dyno to do it. Yeah, it's super expensive but the benefits are large.

Excellent explanation. Thanks!
Now... how much is "expensive"?

I was quoted $350 by the only shop in town with a dyno. But for that you get a perfectly tuned engine. The actually HP/Torque benefits aren't as much as say a new exhaust or anything like that but it's all the other factors that make it worth it. Your bike comes crippled because of the government regulations on them.

The jet kit is mostly compensate for lean spots in your power curve. If you experiance any of these after installing an aftermarket exhaust I would recommend tuning your pilot jets first with the stock jets in them. If you still have lean spots then a jet kit will be needed.

This was easily done on my 500 because of the extra space, but the Hornet is more compact. You may need a special tool to get to the inner carbs.

Anyway, this is how you tune carbs. First you need to find the low end of the carbs. With the bike off, turn the pilot screws all the way in but don't make them too tight. Now back each one out about 2 turns out.

It's helpful to put a piece of tape on your screwdriver with a dot on it, so that you can see how many turns you go.

Then start the bike. Now start to turn each carb .5 turns in, untill you get it to idle rough. Lets say that it starts to idle rough at 1.5 turns out.

Now you need to find the high end. So turn each carb 2.0 turns out again. Now start to back out the screws .5 turns at a time. When it idles rought you have found the high end. Lets say the high end was 3.5 turns out.

Now you just find the middle of those two points which in this case would be about 2.5 turns out.

You're done!

This is SO over my head, it's not even funny. :oops:

It only sounds fancy on paper. All you need to do is turn four screws. One on the bottom of each carb.

But I know how you feel. I had to work my way up to this stuff over the years. Start by finding your air filter and lubing your cable. We'll go from there.

LOL its a lil bit more involved then that but basically yeh

Carb tuning is alot of work, in theory is simple but practice it is a different story. I have been messing with a single piston/carb motor and that took me about 6months of playing around with to get running well in all conditions. Adjusted every thing from changing main jet, slow jet, needle, needle spring, everything that can be adusted/changed on a carb.

The factory setting will work best in all conditions. Getting it tuned via dyno will only be optimized for the condition that it was tune that day.

I wanted to add one more thing. The inner carbs on the hornet should be .5 turns richer than the outer two.

The reason is that the inner pistons get hotter and the richer mixture has a cooling effect.

Yes you can make it a complex thing, but if you add a slip on the only thing that needs to be adjusted in most cases is the pilot screw.