i need help from u guys and some one to explain it to me please

[416 racer]

all right here the problem guys i fell like ive lost performance in my 3 month old engine it has 11 to 1 compresoind on the piston the piston is a 416cc hotcam stage 2 cam and fully ported and polished i hade a white brother on it and the thing ripped but then i sold my white brother and now i have the full stock system on and its been on for 5 weeks are more do u think its hert my motor and im getting my sparks x-6 system some time this week and should that bring my power back im runing a 16 tooth front sprocket on and i used 89 octane with maxima octane booster in it would of that hert my piston please help me with this because im worried about it.

[redracer10]

seems like you have to much work in your engine and not enough other accesories to compliment it. If you had your atv jetted with your White Brothers and then you took it off and put your stock exhaust back on you should have got your atv rejetted if you didn't do that.. Also try to get more inflow, some accesories that will help air inflow are... Pro flow design air filter, K&N powerlid, air scoops... all those parts are cheaply found at my favorite place to buy parts from www.rockymountainatv.com they get parts to you fast and they are the nicest people when it comes to service you will meet.

[2004exrider]

Im sure you've lost a bit of power. Did you change the jettingafter you put the stock exhaust back on because if not you are running extremely rich. Dont run octane booster it doesnt raise the octane as much as it says it does which can make your engine run hotter and get pre det from not having a higher octane fuel, second it will gum up your carb. Buy 93 octane, a little more money but you know your engine is gonna last longer.

Jimmy

[416 racer]

i did not rejet it but i aint runing it no mor until i get my sparks exausht

[bh2285]

What kind of noise would you hear if you had Pre Det???

[2004exrider]

Sounds like a pinging or knock/tick.

Jimmy

[flauge]

It has to be detonating because the manual says w/ it being stock that it needs to run 93. and youre running a hi comp piston too,93 should be a must. i doubt 89 and an octane boost would take it to 93 since most octane boosters only add only mabe a couple of points to your octane level.. if i was you, id put that sparks on, fill it w/ 93 and it oughta run better........

[bh2285]

Would pre det. be as you are throttling it or when you let off the throttle?

[416 racer]

should rejet and lower the front sprocket and is the 89 octane hurting my piston

[underpowered]

Originally posted by bh2285
Would pre det. be as you are throttling it or when you let off the throttle?

pre-det is under a load. sound like a ping or knock from the top end of the motor. (almost as if teh valves are hitting the piston).

If you are getting a new pipe soon, just leave the jetting. if anything it is helping you by running rich and keeping teh re-det down some. if it was jetted properly if would ping even more. i would run 93 in in all the time, it would help keep pinging down, if not eliminate it. Changeing you sprocket wont do anthing, other than take a little load off the engine.

[416 racer]

well i dont here aknok or pinging from the top end i just not acclerating a fast anymor and im hoping that the pipe will bring my 416ex back to life

[underpowered]

it is probably just becuase you are so rich. you had to go up in your jetting with the pipe, correct? well you too the pipe off and left the jetting the same, correct? well you are running rich, which will cause it to be sluggish because it is trying to burn off the excess fuel.

[416 racer]

thank but um when i get it the pipe im goin gto rejet and should it be backed to normal

[coryatver]

going to a stock system you will loose a lot of performance! around 10 hp through the power band!:(