Running higher octane, need some help

[Tri-ZNate]

this weekend I decided to put some high octane (93) gas in my SX just to see if I would notice any difference in power, acceleration, and just to do it. Well I didnt really notice any difference in power or acceleration which I wasnt expecting but one thing I surely wasnt expecting is that when I rev it from about 3/4 throttle up to full throttle it will smoke and it wasnt doing this before.

I was told that because there is more octane or something, when I get up in the higher rpms the engine cant burn all the gas so what I see as smoke is a combo of unburned, semi-burned and burned fuel.

Any thoughts, and if I adjust the fuel air mixture screw will it help any or would I have to rejet? I only get $10 bucks a week to spend on fuel so dont just tell me to dump it out and put in the cheap stuff.

[Lots_Of_Nothing]

Dump it out and run regular.

You will not see any gains from running higher octane unless you need it. How many times does this need to be explained on this board.

[Oldshell4481]

just run it through 'er.. you'll know better next time i guess.

[Huffa]

I wouldn't dump it out, just run it down 1/2 way and fill it with low octane. That will be equivelent then to 89 or so.

I see you have 3 SX's. I am in the process of getting one (85) also.

Any weak points on them as far as things breaking, coming loose or needing more attention then usual?

[Tri-ZNate]

Any weak points on them as far as things breaking, coming loose or needing more attention then usual?

Weak points and breaking - As long as you have the skid plate on you wont hurt anything nor will you ever bend the axel since its enclosed

Comming loose - I go mud bogging, water boggin, and trail riding on wekends and in the year and a half that ive had my SXs nothing had come loose.

Things that need more attension than usual - The rear brake drum, on my three at least, have water and mud in the brake drum after I go through the mud bogs and water. if you dont go through that kind of stuff then your brakes are constant and will last a very long time.

[mad_max]

As far as Octane is concerned... all the crap you see on TV about the benefits of High Octane gas is just that...crap. Octane basically makes gas less prone to igniting, that way pinging/preignition (which is uncontrolled burning) is lessened. Like Lots_Of_Nothing said above if you dont need it dont run it.

Any weak points on them as far as things breaking, coming loose or needing more attention then usual?

Pay attention to shifting problems. Particulary the shifter not returning to a level position. There is a shift pin under the left side cover that may break.

Pay attention to the rubber boot that covers the *-joint and keep the rearend oil clean and change it regularly, especially if you like to play submarine commander.

BTW you can bend a SX axle... when I got mine it was bent where it exits the housing. I'm guessing the previous owner hit a tree with it.

SX are a great trike!

[deathman53]

I run either 100 cam 2 or klotz 114 in my 250r(220lbs) and crf450r(11.5:1),but they need it to run right, my 200x with a 10.25:1 piston I use 93 or 94(only sunoco has 94 around here). if you have compression under 10.5:1 you shouldn't need anything more than 94, BUT also timing has a big part with this,if its advnaced more than 6 degrees high octane(100+) is needed.

[short4stuff]

I run either 100 cam 2 or klotz 114 in my 250r(220lbs) and crf450r(11.5:1),but they need it to run right, my 200x with a 10.25:1 piston I use 93 or 94(only sunoco has 94 around here). if you have compression under 10.5:1 you shouldn't need anything more than 94, BUT also timing has a big part with this,if its advnaced more than 6 degrees high octane(100+) is needed.

If its advanced?.. I always thought that if you advance it well then yeah pre det wouldn't be a problem cause your sparking eariler.. With my 10.25:1 in my 200x I am sure it pings with 87 and with 91 .... if i retard some will that help?

sorry to steal thread.

[deathman53]

advancing keys are popular for 400ex's, blasters, 300ex's, they tend to dvance the timing from 4-6 degrees. I don't know much about 83-85 200x's, I know a 86 can't be adjusted(maybe it could back in the day). I run the cr ignition on my atc250r a tad avanced to make better low end power. when it pings in a 2 stroke it sounds like a hitting your frame, never had it happen in a 4 stroke. it shouldn't ping with 91, yes 87, but not 91-94.

[ewalker302]

I have an advance key in my 400 and have no problems running regular.