high idle

[mclarenyamaha]

if it goes on 1500 rpm and you blipp the trottle it takes 5-6 seconds before it goes down 1500 again. when it stays there it can suddently cut and back to 1500 rpm. it is not before you touch the trottel theproblem is comming, either driving or stand still

 

[rxrider]

What happens if you add chocke while at high idle?

 

[mclarenyamaha]

first a littele bit up, then down, i will try the fuel screw 1/2 turn out

 

[rxrider]

Sounds like lean idle, letting the pilot screws out should help if you have a lean idle problem. Let us know how it works.

 

[mclarenyamaha]

how many turns out should i try on the fuel mixture screws, stock was from 1,1/2 to 2,1/2 very diffrent on all 4 could this be the cause to the high idling. have set them to 2 turns out will try on wedensday. is it sombody who has adjusted these and can come with a tip how much will be the best

 

[Skydog]

They come that why from Yamaha, i would think 2 should be close. But every sled is so diffrant.

Skydog

 

[rxrider]

Skydog is right on - I have my pilot screws out 2 turns across (stock), 17.5 pilot jets (stock), needle 3 position (stock), stock springs are in for now. Idle is set at 1500-1600 rpms. My sled has always ran well with this setup. MCXpress recommend stock carb settings with the 240+ HP kit for 10-14 lbs of boost. If you want more than 14 lbs you have to go larger on the main jets, and you have to lower the compression ratio.

 

[mclarenyamaha]

i have now tried the new carburettor set up with 2 turns out on teh fuel screws. that didnt help. but i did find out that the engine is very sensitve on what rpm it idels on. if i turn the idling down to 1000-1100 rpm it works just fine with this setting. so i dont now, the sync was also fine.

 

[rxrider]

Have you checked your TPS setting? Do you have the service manual, it's all described in there? Shoot me a PM if you need it.

 

[mclarenyamaha]

the tps settin is set to 0.6 volts. have tried diffrent setting but with this volt i have to turn the tps to the right until it stops. does this seems right

 

[FAMILYMAN]

the tps and idle screw work together. Screw one out...screw one in. If you are out of adjustment then you need to move them both together.


Same thing happend to me, but im not going to say I told you so.... Ted Jannett gave me the insite on how that works as well...ty ted!

I am at 1.8895 turns out on my fuel screw also..... 14.5 at idle..well before my a/f sensor to a sh*t.

 

[mclarenyamaha]

does that mean that you can turn up the idling and then readjust the tps to get rid of the problem. if Ted is reading this i would be wery thankfull for his help.