do your 2 stroke roadracers idle?

I have always been told there is no idle air circuit on TZ's and RS's, only a pilot circuit, and in fact, these bikes don't even have idle screws. That is how I set up my CR125 / RS50 hybrid. It won't idle, and requires the blip. I also have a fat pilot in it to keep the piston happy when in high rev zero throttle conditions

How about the other bikes out there? Your street converted track bikes, or any other two stroke road racers out there i have forgotten about ?

 

If my 6 AM sharp paddock experiences account for anything, the answer is no. They do not. And require about 50,000 heat cycles before they're ready to be ran on track.

 

Idling, Hans, does the devil's work. My RS requires hand on throttle for all of the usual reasons and if I were running an RZ or such I would think since a track bike is set-up for more output than as a street-civil device should be, idling is not helping things in there. Besides, it's fun.

 

guilty as charged

 

My RZ based engines will idle but they are jetted pretty fat so if I don't blip they will load up very fast and possibly even foul a plug.

 

You know you love it.

 

there is a pilot jet, you could likely set the carb up to idle, but never seen or heard of it done

My first warm up with my bike on a new piston and ring was ‘there’s no idle!’ As the bike nearly died

have also gotten plenty of stink eye for 6am run in sessions, but hey, I paid to race too!

 

It's to drown out the cheap ass generators that ran all night....

 

Love me some 2 strokes. But my KTM 300 starts right up cold and will idle all day long. I blip it maybe 3-4 times as it warms up enough to turn off the choke.

 

That may well be but your diesel's piston is actually a simple cylindrical shape and its cylinder bore doesn't look like cheddar cheese....

 

Probably closer to Swiss cheese.

 

Yeah it looks like the dirt bikes and enduros all idle beautifully, probably because they are tuned more for that low and partial throttle response, and dont' see the same sort of cylinder temps and loads that a road racer sees on a long straightaway. off topic: I REALLY want one of those TPI ktm 250s

 

I did actually get my RS250 Honda to idle. Once it was started and warmed up, it would idle if the slides were set to be open a little bit. Of course they are not supposed to be set to be open. So it only idled because the throttle cables were not adjusted correctly. parillaguy

 

My stock Aprilia RS250's with the oil injection system still in place did idle just fine. They loaded up some, but not too bad. I would let them idle to warm up with minimal throttle blipping. My RZ race bikes (pre-mix) were jetted super fat down low to help prevent off throttle seizures. Those would idle but load up terribly so I constantly blipped them.

 

I didn't like paying for or changing plugs on the rs or tzr so the throttle got wacked constantly.
Beside the fact it made me feel like a man.

All of my ktm bikes idled perfectly.
125-200-250-380 All were great but couldn't say that about any of the jap dirt bikes.Wonder what ktm did to prevent that?

 

I think part of it is that the designers didn't want anything like a slide stop screw sticking into the airflow. Also, less parts equal less things to potentially go wrong. I filed a small relief in the bottom rear of the slide so that my motor would just about idle. I don't know if it made any difference in the throttle response and I still had to blip the throttle to keep the motor running.

 

Not mine. I always adjust the throttle screw so it won’t idle, so it is completely out of the way and the slides come down completely, so the bike pulls hard on the pilot jet at high rpm/throttle closed to help it stay cool. It will pull a lot of air in and overheat if the slide is up just a little under those conditions.

Many, many years ago I watched a guy seize up a 2 stroke in the 125 mph entry to turn 1 at Vaca Valley, just as he rolled it shut. Sumbitch slid and rolled and tumbled right up and over the top of the banking and out of sight out into the weeds. That memory kind of stuck with me.

But a 2 stroke race bike is so rich with both gas and oil it wouldn’t idle very long anyway before it loaded up and quit. I’m afraid revving it is required. I always have pushed off and immediately gone somewhere to warm it up where the noise and smoke wouldn’t bother folks, or at least kept rolling around the pit roads so no one had to listen to it or breathe it too long.

 

Anybody that doesn't like the aroma of race fuel pre-mixed with 2-stroke oil and burned in an internal combustion engine is weird. Or a degenerate. Or a psychopath. Or all of these.

 

We’ll sure, that’s beyond debate. All of the above. And especially when we used bean oil.

 

I still have about 1/2 a liter of A747.