I ordered a dial a jet today for my predator to give it a try, hoping for better performance from the mods I've done.

I've installed the w/b pipe (9 discs) k&n filter, 38 tooth rear sprocket , vented air box, 160 main jet, raised needle one click(4th position).

I drag raced my friends predator which is bone stock and only pull him by nose in a approx 1/8 mile run. And this is from a 2nd gear roll to eliminate the hole shot so we could see the difference in just the power. Then we whiched quads and raced again and still very close. So either the jetting or the amount of discs in the pipe isn't right! Because it definitly doesn't have 9 hp more than stock. So I ordered more discs and a dial a jet to do more testing. I'll post the results in a week or two.

And yes we raced many times when they were both stock it was in most cases a tie or no gain or loss once off the line.


Has anyone else with mods raced a stock predator for conparison in performance?

 

How did your plug look. This will give a good sign if its jetted right.

 

It's possible that the jetting is too fat, you would know this by hitting the throttle, and if you feel a slight dog before you take off, you are too rich. Also, if you regeared for acceleration, it's possible that he would hang closer and have a little mroe top end if you had to shift a little sooner, or maybe with the added power you spin a little more than before while he hooks up and goes, just some things to think about.

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03 predator

 

How much did you vent the air box?

Try 11 to 12 discs with the airbox mod = to a 2x3 hole.
By changing to a 38 tooth you lost a little top end speed, but you should pull the other quad a little quicker in the lower gears.

 

The upper RPM range has always been the Preds strong point. The addition of the silencer, and a K&N are mainly to "wake-up" the bottom end......so why would you start from a roll. Why not start from a stop, and see the entire range of your advantage? Like the others said, check your plug/jetting, and add some more discs.

Ken

 

Try using 7 disc in your pipe, 160 main jet and move your clip to the 2nd position. also do not modify your air box, except for removing the snorkle pipe. (watch the water). race your buddy and see if this set up helps out. The 6 horsepower gain will be on the low end of the rpm range. If your making 41 max hp now the pipe and rejetting will only get you to about 43 max hp. but it will have about 6 more hp at low rpm's above what it had stock. The superbike shop is way ahead on predator mods and tuning. They have set up a message board on there site to discuss mods and setups. this is the best setup according to them. haven't tried it yet.

 

What is the size of the main jet STOCK? Did you install a larger main to compensate for the pipe/airbox/filter mods? Dial-a-Jet
must be set up with a LEAN condition on your bike, meaning if your stock jet was 160, and without mods (pipe, etc) dial-a-jet
would allow you to decrease the main jet by 3 or 4 sizes. After all of your modifications, you might be able to stay with the
stock main jet. Dial-a-jet will never let your motor burn too lean. It works better with a lean condition. It only adds fuel to the
motor, never taking away. So if your rich now, Dial a jet will not make it any leaner, only richer. So always create a lean condition.
And your plug will be much lighter in color that what your used to. Since the system emusifies the fuel with air, it burns much cleaner
than normal. So even tan plugs "might" be too lean. www.thunderproducts.com has an excellent article on how the whole system
works. It's a combination of airflow, vacuum, and acoustics. ( acoustic sound signal amplifies or de-amplifies the reversionary
pulse waves of the intact tract ) Read the article, learn a lot.

Bill

'03 Rincon