Throttle hang on Viper

kinger

kinger

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Joined
Nov 12, 2004
Messages
796
Location
Clear Lake, IA
I noticed when riding my Viper this year that the throttle will sometimes hang at 4K rpms when I come to a stop, I have to blip the throttle to get it to come down. One time it even revved up a little after I was completely stopped and it engaged the clutch then settled right back on 1800 after that. It was a non-event but I'm worried sometime about going down a hill and needing to slow down.

Thoughts?
 
its lean, turn out the fuel screws about a 1/2-3/4 turn more, will totally cure the problem, this is very common with flatslide carbs.
 
Cool where abouts are the fuel screw located? Can you buy a shop manual for these things? Thanks for the help!
 
They are on the bottom of the carbs, you have to pull them to get at them. You can get a shop manual from Yamaha. I dont know how much good the adjustment will do, I have mone turned out to 2 1/4 turns, a half turn out more than stock and it still does this.
 
MrViper700 hit the nail on the head but if you made no mods to your sled & it started hanging the idle you may want to try & turn down the idle a bit first. The fuel screws on a Yami are a pain in the a$$. Get the sled to idle around 1400-1500 RPM's & your problem should go away. Randy
 
I have two vipers and both do it. like bushman said get the idle rpms down to 14-1500 and you will be fine. just turn down your idle screw on the top of the carbs. When the temps change you just readjust a little
 
nodoo_s said:
I have two vipers and both do it. like bushman said get the idle rpms down to 14-1500 and you will be fine. just turn down your idle screw on the top of the carbs. When the temps change you just readjust a little
Click to expand...

How has things been going Nodoo_s? Good to hear from you!
 
OK I had the idle at 1400 and it would sit there and shake and rattle the hood so bad I upped it to spec 1800 and it smoothed everything out. I'll turn her back down. Much easier then pulling the carbs! Thanks!
 
Hanging Idle

Kinger,

Did lowering your idle speed to 1800 RPM take care of the hanging idle? I just returned from my first trip with my recently purchased 02' Viper and experienced the same problem. I also noticed two other issues that I do know if they are related.

There was a couple times when I shut off the engine it would back fire. I also had issues starting the engine. Some times it would fire on one pull when warm and others it would take three pulls to get it started also when warm. This is my first Yamaha after riding nothing but Polaris. Maybe this starting deal is just the way they are. I do not know????

G.B.
 
guys, fix it the right way!

Gone blue, the correct way to fix this is to simply turn out the fuel screws a 1/2 to 3/4 turn more, its lean thats why it hangs up! When ya set them at 3/4 turn more, they are cured. Also, I will let ya in on a tip, if you just touch and I mean just touch the throttle when you pull it over warm, it will leap to life, just a crack and they will start 1st pull all the time when warm. Next time the idle hangs up, blip the choke once and youll see it come right back down, the motors telling you its lean in the idle circuit, its because of the flatslide carbs, this is very common. You can band aid the fix all you want to, but the only cure is turning the screws....................
 
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Yes resetting the idle cured the hang. mrviper I'm sure is right but this took me all of 15 seconds, I'll adjust the fuel screws when I clean the carbs.

Also to start I have to just crack the throttle and and boom she comes to life one pull...again mrviper is right.
 
My Viper Did This When It Was New And The Idle Was Too High. It Needs To Be Set Under 1500 Rpm And It Will Cure It. And Yamahas Are Known To Start A Little Hard After Thay Are Warm. Something To Do With The Flat Slide Carbs. When You Go To Start It Just Put Thumb On The Throttle And Blip It When You Pull It Over And It Will Start Everytime. Goodluck And Vipers Are Awsome Sleds. Nothing Corners As Well.
 
Thank's to all for their information. I think that I will do both, lower the idle speed and adjust the fuel screws. My sled seems to idle right near 2000 RPM when warm. That seems a little high to me.

Mr. Viper, I have not pulled the plugs yet to see what they look like after my first trip. I plan on doing my post trip inspection tonight. Do you know if this lean condition is only at idle or is it all the time?

Oh by the way, this Viper is awsome! I kept waitng for the inside ski to lift (ie: Polaris) and it never did. I really like that this machine doesnt feel like a big heavy 700 on the trail. It rocks!

Thanks again, G.B.
 
viper idle speed

Gone blu: its only lean in the idle circuit. The factory spec for idle speed is 1800rpm + or - 100rpm, so 1700-1900rpm is where its supposed to be, and turning them below that will make them run like a harley.....lol, :WayCool:
 
Thanks Mr. Viper! I was hoping that you would say that. I am counting on seeing dark grey/black color plugs and not white ones when I pull them tonight. It ran real strong so I was hoping that the there was only something funky with the idle circuit. Ride on! G.B.
 
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