860 bb tuning

[Draxxus]

Hey recently picked up a 09 163 engine tech 860 big bore ive been impressed with the increase in power but more reading on others bb posts makes me think there is lots more in my new girl.
I ride with a new 163 e tec stock and it very distinctly will out pull me.
ive heard of lots of guys saying that there tuned bb will pull way harder than new e tec. so what should i be looking to do here, get some adjustable tra7 arm weights? new skid? new track? different ecm flash? im thinking its sumthing to do with the clutching or the ecm. my current complaint is that some times when im wot it sounds like its hitting a rev limiter , my old stock 154 never did that , it would just pull to 8000ish and stay there. new girl rips up to 7800-8000 and sum times does this rev limiter thing, its strange. also the e tec owner had a stock 154 at the same time as i had the 154 and i always used to high mark him cause im lighter... so whats holding this new girl back??? I know its not a rider issue I am quite capable of grabbing a fist full and riding hard.

here is some more info on what has already been done to this new girl
slp intake , high flow air box , was running 490 mains droped to 480 mains cause of fouling, needle is shimmed, slp y pipe , stock pipe, slp can ,running aftermarket ramps ill have to crack it open and check which ones again, after market springs in secondary and primary not sure what kit..... and a 44/36 helix, engine tech thermostat housing and new thermostat, limiter strap all the way out, springs set at 5 front at 3. I know its not a rider issue I am quite capable of grabing a fist full and riding hard. riding average 3000ft-6000ft bc mountains whistler and such. I weigh 150lbs

thanks any input would be apreciated

 

[winter brew]

Let us know what's in the primary. Stock ECM should be fine. Has the timing been changed?
Is the wierd "rev-limiter" thing the detonation sensor?
Comp ratio? Fuel being used?

 

[Draxxus]

ill find out about the ramps and compression on the head, fuel is 91 octain, ill give the guy i got it off a call and see if he did a ecm flash already i have a feeling he did, and i dont think its a deto sensor no engine light.

 

[winter brew]

Just a heads up....don't rely on the deto sensor. I have rattled the plugs out of these and had audible detonation without the sensor going off. Seems it only goes off when it gets VERY bad.
Try throwing some race fuel at it and see if things change.

 

[Draxxus]

13.5:1 head 415 ramps, ecu went to engine tech who sends it to ski doo racing and they advance timing at top end and slow timing a lil in the mid range. was recomended to set needle clip at 15th of thou and make sure pilots are 2.0, ill have to pull that apart and the clutches to see what springs i am running, also recomended boyesen x wing and reeds in combo with secondary spring at 160/320 .... does this sound like a good setup ?

 

[winter brew]

I had to run 50% race fuel with 13.5, same elevation (3-7k). My timing was advanced 1*, stock ECM, 470 mains, shimmed needle, stock pipe, Straightline Y & silencer.
Clutching will depend on helix angle....what you have listed will be good as long as the helix is compatible.....I assume you meant 160/320 primary spring?

 

[Draxxus]

50% race fule to reduce deto? yeah probly the primary spring, are you running any reeds or power wings?

 

[MontanaPowder]

860 jaws twins

Find a friend with a xp stock ecm. Go to hill and trade, takes 5 minutes to switch.

If no work then try fuel.

I gained 700 rpm by doing so. I then sent box back for stock timing, rev limiter to 9000 and remove overtemp retard.

Hope it helps.

Mine pulls 8500 rpm and has for 2.5 years. They run strong.

 

[Draxxus]

thanks sounds like a good test method ill try it

 

[byeatts]

Find a friend with a xp stock ecm. Go to hill and trade, takes 5 minutes to switch.

If no work then try fuel.

I gained 700 rpm by doing so. I then sent box back for stock timing, rev limiter to 9000 and remove overtemp retard.

Hope it helps.

Mine pulls 8500 rpm and has for 2.5 years. They run strong.

we had a bad ECM program mod as well.Same thing trouble hitting RPM,s

 

[Draxxus]

how did u fix it ? remap ecu or just swap in stocker?

 

[Draxxus]

can i put a 07 ptek ecu in my 09 ? shoud be the same no ?

 

[dicey]

Not the same none of your gauges will work

 

[Draxxus]

balls

 

[mtnjunkie]

What elevation? Have you checked your piston wash? 490s might just be too rich, that will cause you to lose a lot of power. I use 3 gallons 100LL, and it seems to run best with 460s. Rode low elevations for a few weeks (like 5K-7K) and it ran best with 470s. But too rich much higher than that. I don't have ecm reprogram, and a 14:1 head.
You might try some different ramps too, I never really liked the 415s that much, but that's just me.

 

[Bendy]

Pipe?

Wouldn't you have to run a larger volume pipe with a big bore? Never heard of anyone running a big bore with stock pipe.

 

[Draxxus]

its a engine tech thing i think

 

[Draxxus]

Dosnt matter now bottom end blew out

 

[970SnowSlayer]

any more info on what exactly happened? this was an ET860 kit? how many miles on the kit/total on the sled?

 

[Draxxus]

1500km on bb piston went exhaust side , con rod snapped and punched through both sides of block not sure what caused piston failure yet , to lean or detonation, other piston was heavily scored