I believe it has to do with environmental conditions and how much time and effort you are willing to spend tuning the engine, clutch and gearing, given different fuels, plugs and pipes. If you think about the possible combinations, it's staggering. If you have the time, good intuition and experience trying different things, you can quickly make some intelligent choices as to how to improve the performance of the engine.

Although some people say, "Listen to the engine, watch for white smoke, watch how the clutch engages and watch where it shifts", it's not as easy as it sounds. Some people have a knack for tuning, some people don't have a clue and most fall somewhere inbetween.

Based on the opinions posted here and some other PMs I've exchanged, the jury is split on the STI's performance on smaller tracks. The only conclusion I can come to, is that the STI has the potential to do well on smaller tracks, based on how it's tuned.

i went to run in my new sti today at fastcats (a short track) and i know i said that the sti kinda sucked on short tracks but this thing that kyosho gave me is totaly nuts and im running 16% the thing is fast, now what i think it is is that the sti is so smooth it seems it has no grunt BUT it helps me drive better so therefor i do better lap times so i say now its a good short track motor there are other motors that have umm can i say balls but to do a 45min main ahhhhh its a handfull, i just hope i dont break this crank.

Does anyone have a link to show how to replace the connecting rod? This is my first attempt, but I want some direction before I mess up something.

Listen....there is nothing wrong with the Sirios on short or long tracks....
I just finished my first state race with the Sti and its not a very big track and the motor was out of control with tons of bottom end actually too much...I should have probably loosened the clutch cause our conditions were not ideal and in our local track in Ft. Lauderdale even smaller track the motor has no problems.....at a big track like Glc motor was flawless ...Ft.myers this weekend Flawless... I have yet to have a problem And i still feel the motor will get faster that's the funny thing

Sorry I dont have one.....but I can tell you is too use some very small needle nose pliers...remeber the direction of all pieces you take apart it should reassembled identically to way it was......use a white towel under your work area just in case you drop the clip that holds the pin which slides through the piston. Those clips are very easy too loose its happen to me many of times that why I always have plenty spares....I hope this helps good luck

thats what i said LOL

I'm sorry you guy,I'm green on this sirio sti
question is what is the best fuel brands, glow plug temperture heat range,
pipe for open track?
Dose Sirio still have issued with the carb needle o ring?? or any problem I need to look into...Thnaks

Does or has anyone had troubles with air leaks around the base of the carby where it seals on the crank case? or as above needle o'rings? i have never heard of the needle o'ring issue before, but with what my motor is doing i can relate.

I like tornado fuel 25 %...pipe ive been using the nova 2630 and sirio 2611 both are very good..havent had any problems with motor...they have worked flawlessy for me

No I havent had anyy issues wish i could help out..check all your orings make sure they are in good shape also check your bearings....

i run tornado 16%,sirio #6,temps 225 to 235, SIR pipe

dose it idle up mine dose this but only when it was still new,after running it for a bit it idles fine, the compression on this thing is so high when new and it takes a long time to break in to give a nice low idle

thanks

broke my crank again AGAIN and i have no clue why i have never broke a crank befor these 2 sirios so idono.