High idle after new pistons?

[CROW]

As a preventative measure, I pulled the motor on my '12 800 and put new RKT pistons in. Everything turned out great, except it idles around 24-2500 RPM. Occasionally it will settle down to 1900, but it's not often. TPS was replaced last season and it idled great before the piston swap. Currently no codes. Throttle free play is good. Any ideas?

 

[K2]

air leak ?

 

[jrnbrg]

If it drops to normal idle on occation, it can be that your idle was set a tiny bit to high when the tps was changed last year. And now with new fresh pistons it just idle easier, try backing the idle adjuster of 1/4 turn.

 

[CROW]

Do you think a 1/4 turn will require another TPS adjustment ?

 

[yotaman1290]

Check for air leaks and also check the throttle free play and look at the throttle body make sure the throttle is actually closing all the way

 

[CROW]

Checked for air leaks and free play, both good.

 

[jrnbrg]

Do you think a 1/4 turn will require another TPS adjustment ?

Mine didnt require another adjustment, it was fine for two seasons after that. And still runs great, sold it to a friend before this season started.
I can't say for sure that this is your problem, but sounds just like what I was experiencing.
Tps/idle adjusted when dealer was troubleshooting runnability issues, then changed pistons because of worn out ring groves.

 

[sled_guy]

And you are sure you got the little rubber washers in under the injectors?

sled_guy

 

[CROW]

Didn't pull the injectors.

 

[die hard poo]

Check your voltage at idle. It should be .93V +- .01. Then try riding it for a tank and see if it goes away.

 

[TRS]

Checked for air leaks and free play, both good.

Did you use carb cleaner to check for air leaks? Or visual?

 

[CROW]

Carb cleaner.

 

[Indy_500]

Just curious if you checked compression before and after rebuild? Maybe you bumped up 20-30 psi and the fuel you are using is too lean for your setup? Sounds dumb i know.

 

[CROW]

I went a 1/4 turn on the idle screw and that helped...some. Once I get it back to the garage I'll adjust it more. Still idles high initially, seems to come down more often now.

 

[sled_guy]

May just need to go through the engine setup again. My dealer charges 1/2 hour of time to do it with the Digital Wrench. Last time I did a FixKit on a Dragon when it was all back together it idled high. I suppose freshening the motor just was enough different. Took it to the dealer and had them set the TPS, Idle, etc.

sled_guy