choke questions

[slowpoke]

im thinking there might be an issue with my choke adjustment. explain to me the functions of the choke on an 05 please? the reason why i ask is my bike in particular ive never used the full choke until this year. a couple times i think i flooded the bike recently. it wouldnt kick off, revolutions were strained ( like a low battery) and it smells of fuel stronger than normal. well i decided to experiment a bit and put it on full choke. the motor started spinning fast but still wouldnt kick off. ( only did it about 6 revolutions or so) then since it didnt try to fire off ( acted like fuel was shut off) i turned it to half choke and bam, she fired right up ( sluggish but was idling and then cleared up as it should)

my question is, does the choke on my bike work like a carb vehicle say from the 80s meaning it only restricts air flow? or does full choke indeed cut the fuel off as well? if it doesnt cut the fuel off on my 05, does that mean my choke is out of adjustment and shutting all the air flow off?


im kind of wondering if its just out of adjustment to be honest

 

[jfeagins]

I believe the choke enables MORE gas to enter into the carb. More choke = richer running. But it does not restrict the air flow as did the early carb auto's you mention.

 

[slowpoke]

Hmmm that blows both my theories out of the water then. i was hoping that either it shut fuel off on full choke and everything was fine or it just operated the butterflies and in my case they were closing too much and not allowing any air to enter the carbs resulting in a no start result. which would be fixable via adjustement screw or something simple heh.

 

[maleko89]

It's basically a bypass that allows pure fuel (no mixture) to get into cylinder. If you can start w/o choke when engine is cold....you are rich. I've never had to use full choke so probably lean or something up with ignition, plugs.

 

[slowpoke]

normally it starts like clockwork with half choke when engine is cold. theres just been a few times ive had issues lately and i noticed full choke acted like in my description.

 

[SpecOps13]

Have there been temperature differences when it's acted strangely? I'm in Florida so there's not much temperature variation to contend with. My 2 VMax's always start with half choke when cold... Good Luck figuring this one out....

 

[slowpoke]

most definatly, weve had lows in the 50 - 54 range with highs in the low 80s here lately. that being said last year even when it was 40 degrees outside it would fire up with half choke. just took a bit longer to warm up is all. according to my nose my bike is running rich. there is no way it can be lean with the smell of my exhaust. ( even have a black ring on my stainless 2 1/2 inch kerker baffle cap) this issue has literally only happened 3 times this year. so its not a common occurance. however 2 of the 3 times have happened within the last 90 days or so. oh well, guess ill just keep riding it as is. apparently it isnt a major issue. i just thought it was odd that on full choke it didnt even try to start and turned over much faster than at half choke when it seemed like i had flooded it. then went back to half choke and she fired right up heh.

 

[Rhoy Carter]

When mine got hard to start like that i changed the plugs and that cured it

 

[slowpoke]

thats something to look into. i did do the cops mod about 3 months ago but i didnt replace the plugs because they still looked good. also i havent changed the plugs in 3 years. maybe i shouldnt have gapped them at .030 ill take a look at them over the weekend. maybe close the gap a bit if they still dont look worn.

 

[RaWarrior]

I've never encountered any motor that didn't run fine on the "default" gap that plugs come set at. Spark plugs, even regular non platimum/iridium ones, last a very, very long time. 100k+ miles. Changing them constantly in powersports seems to be one of those trends with no real reason behind it. My bike has had the same plugs for 3 years and they're all fine.

The vmax uses a bypass "enrichener" circuit. When you press the lever down and the little forks pull the plungers outward, that opens up a small secondary venturi that adds a very rich flow of mixture out of it. These chokes only work if the throttle is closed, otherwise there won't be enough vacuum (it'll all go through the main venturi instead).

Mine never needs full, 1/2 or so when cold. It'll idle no choke almost instantly, although it's slow and weak until it warms up. I'll keep it on until I take off driving, then turn it off.

It's not unexpected that the motor would crank slightly faster with the choke open, since that extra passage is now open in the carbs, reducing manifold vacuum slightly.

 

[Maxine]

As others have already stated. The "choke" is not actually a choke in the sense that it does not choke off the air flow. It bypasses the normal flow within the carb and "enrichen's" the mixture. Nowadays its more accurate to call them enrichener's.
If you are starting the bike from cold with no choke/enrichener then you are probably tuned fairly rich.
Regards,
R