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Discussion Starter · #1 ·
New 416 wiseco 11.1 top end using cometic gaskets. About half tank through it for break in so far. Im ready to run higher rpms through all gears without hitting the limiter. Im using 93 octane and im hearing i beleive detonation.its not a pinging like heard in cars.kinda sounds like a faint dry wheel bearing.only does it when in 2nd at mid rpm when i full throttle it and stops just before i shift.. I dont want to continue riding it and ruin it.
My only mods are 416cc wiseco 11.1, uni air filter with hole cut out of lid and stock exhaust gutted out. I put a 170 main and 42 pilot jet in.
Here i can get 93 octane but anything higher then that have to drive like 5 hours to get anything else. Is there any type of octane booster i can use to up the octane? Im not a racer just casual riding with my 7yo son. Im about 100ft above sea level.
 

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Look for 94 octane VP Racing SEF (small engine fuel) - you can also raise octane with a small amount of 2 stroke oil 80 to 100:1 mix or by adding 10% ethanol (raises about 2 octane points) and it is also possible to add 87 or 89 to 93 and get 94 to 95 octane, but you would have to be a chemist to verify the result of the mixture.

You might just try enriching the fuel to air mixture in the mid range by raising the slide needle one notch.

Also; be aware the Wiseco piston is forged - it requires more cold clearance than the OEM cast piston and takes longer to expand which means about a 15 to 20 minute ride at moderate speed to allow for full expansion of the piston. If the technician who honed the cylinder to final clearance was a novice, having a bad day or was just being sloppy an extra .0005" of clearance will allow piston slap and the noise may occur as a harmonic at a certain RPM - Wiseco pistons are for racing and noise is acceptable in a race engine.
 

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Discussion Starter · #3 ·
My tractor supply has single gallon of vp race fuel for 23 bucks.. My autozone has vp race fuel additive 32oz for 23 bucks. Is additive any good?
Also im only using 93 from the gas station up the rd citgo. Dont know if another gas stations 93 will be better
 

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Do you understand the difference between pre-ignition and detonation?

Do you know what piston slap sounds like?

What kind of oil are you using in the engine?
 

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Discussion Starter · #5 ·
I know what piston slap is.sounds nothing like that. It's deff not a pinging.its a wierd sound i never heard before. Wasnt there with the 10.1 piston. And im using rotella 15w40 oil
 

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Discussion Starter · #6 ·
I did go from a 148 to a 170 main and 38 to 42 i believe pilot and 3.5 turns out on air screw.
Figured since the jetting was stock id start there and dial it in but dont know if its needed with only the uni air filter and lid cut open and baffle removed from thr stock exhaust.
 

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Discussion Starter · #7 ·
I can get 110 for 10.50 a gallon only 30 miles away...what should my jetting be?i feel my jetting is wrong amd thats the main cause of my problem. I was told with just a big bore my stock jetting should not have to be changed unless i get to 12.1 compression.im going to go back to stock jetting and cover the airbox lid.
And what would be the recommended fuel mix? Start with a 50% 110 and 50% 93?
 

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Discussion Starter · #8 ·
Ok. Sorry for all the replies... I went back to the stock 38 pilot and 148 main.my needle wasnt adjustable so i used 2 small washers to space the needle up... Air screw is still 3.5 turns out...air lid still cut open. Took a ride let it warm up.still on 93 gas. Seemed to run great. No more noise i had.still didnt rev high enough to hit limiter so i didnt want to over rev it.. No more noise under load. Still driving it to make sure. Also new plug color is a light toast color after a short 20 min ride various throttle positions.
 

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Sounds like you are getting there without my help. I starter working on this reply about 3 hours ago and interruptions prevented me from finishing it until just now.

Changes to the exhaust affect top end jetting (does not affect or has very little effect on idle) - changes to the intake greatly affect idle and mid-range with a mild effect to top end. True - just changing the bore does not require re-jetting the carb. The fuel screw only affects idle - with an initial setting of 2.5 turns out from lightly seated, ride the vehicle for about 20 minutes then to properly set the fuel screw, turn the screw in in 1/8 turn increments pausing 5 to 10 seconds between adjustments or observe the effect on idle - when the engine rpm drops by 50 rpm, turn the screw out one full turn from that point and the idle is set. With out an accurate tach and or patience for setting the idle properly; turn the screw in until it affects idle then back the screw out until it affects idle - the final setting is somewhere between the two extremes where the engine seems to idle smoothest with the least throttle lag upon acceleration.

Fuel should not exceed 94.5 to 96 octane - start with pure 91 - 93 octane (non-ethanol)

I did not know Rotella had a JASO rated oil. JASO rated oil will enhance transmission and clutch life - non JASO rated oil will damage the clutch first and the transmission will just deteriorate slowly over time until the teeth wear away.

Pre-ignition is when the fuel ignites spontaneously from heat, compression or a hot spot in the combustion chamber. Left uncontrolled, it will burn a hole in the piston. Pre-ignition may be addressed with a higher octane fuel which is harder to ignite and burns slower than lower octane fuel.

Detonation happens when too high of an octane fuel is used. The mixture is ignited and the expanding air pushes the piston. When the piston reaches BDC and starts back up, if the mixture is still expanding, the unburned mixture is compressed between the expanding air and the rising piston resulting in the unburned portion of the mixture detonating between the pressure wave and the rising piston. This can result in bent rods and or broken pistons.

I don't believe you need fuel with an octane above 94.
 

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Discussion Starter · #10 ·
I read others using rotella cause its a good oil and supports jaso so i got it from my walmart.
Im going to use ur advise on idle setting with the air screw. I have patience to a point. I want it to run at its greatest. I dont need the choke to start it but i do need to hit the gas a couple times while cranking to start no matter if its cold or hot but after it starts itll idle fine. Is this normal for a ex?
I can crank for an hour without hitting the gas and it just turns over like it wants to start but the second i hit the gas it starts right up.
I have no popping on deceleration.no hesitation on acceleration.no 1/4-3/4 throttle stumble
I think its coming along great of course with the help from this forum
 

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When you open the throttle, you are giving it air - not gas - it starts because opening the throttle leans the mixture and it ignites - you can turn up the idle or cutback on the idle circuit fuel supply. Everyone says my machines idle too high, but I have no problem starting them - no special procedure like some others I know.
 

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Discussion Starter · #12 ·
Yea i dont like my machines idling high. The fuel screw would be the adjustment i need for better starting? I mean i can live with having to gas it to start it but if its not normal then i would like to have it the way it should be
 

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Discussion Starter · #13 ·
I also read others going to a 42 pilot to aid in hard starting issues in cold weather but since im in southern georgia its not cold here...should i stay with the stock 38 or up it or should i wait and see how thel fuel screw is after i tune it?
 

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Discussion Starter · #14 ·
Ok i went for a long easy ride and when the motor gets really hot the noise is back at quick wot pulls. Can get on it easy wot and dont make the sound. The plug is still light toast color.
It almost sounds like a faint baby rattle.
 

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Discussion Starter · #16 ·
Ok ill get the 9z tomorrow and try it again. What company sells the best 93 gas? Exxon?
 

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Ok ill get the 9z tomorrow and try it again. What company sells the best 93 gas? Exxon?
I don't know about that - I buy my fuel in bulk (250 to 300 gallons at a time) 91 octane non ethanol Agricultural (farm) gas and just use it in all my vehicles.
 

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That's why I buy AG gas - farmers are exempt from using alcohol blended fuel because farm machinery is too expensive to repair/replace alcohol damaged components. We have one station about 25 miles from me that has 91 octane non ethanol at the pump - $3.90 a gal - I get AG gas for $2.15 a gallon before taxes - after tax it costs $2.87 a gal, but that was before the last hike in wholesale price and the increase in tax - it will be about the end of this month before I am due for a refill.

In most plugs, NGK, ND, Bosch and others - the higher the number the colder the plug - Champion is the opposite
 
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