viper fuel screw setting?

n2oiroc

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Sep 5, 2004
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milwaukee, wi
i was told vipers are hard starting because of a lean fuel screw setting. it was suggested to set them to 1 3/4 turns. stock is 1 7/8 turns. isnt this leaning it out? what is a good setting?
 

the fuel screws are just that, fuel supply. out is rich, in is lean. on the older carbs, this is an air screw and the reverse is true. when is it hard starting? warm, cold???? ski
 
it starts good, but it just doesnt run good cold. i have to play with the choke a lot. it idles weak and a little low for a minute or two. it isnt like my polaris, i fire it on full choke, go to half for a few seconds and its all good. i could play with the throttle if i want to on the polaris.
 
sorry yamis are a little cold blooded, cant compare it to a polaris. i would up the idle to compensate if i were you.

yamaha triple start procedure i use.

full choke a cold sled till it starts, let it run until the idle drops alittle, half choke til the idle drops again, walk away and put your gear on. if it needs a blip or two to half choke to keep running so be it. but other than that dont touch the throttle till ALL of the heat exchangers are warm.

if the idle is low and wont hold an idle at cold start, turn the idle adjuster up.

i use this method, never fouled a plug on 3 yam triples, 2 of which were pv motors. ski
 


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