jetting???

[xkingraptor350x]

now this isnt one of those wht jet should i use thread... but i have a question concerning weather. now if you jet for the summer right. in the winter you should be running lean right? or rich? right now im really rich plug is soaked in gas and its black

 

[DeathShadow]

now this isnt one of those wht jet should i use thread... but i have a question concerning weather. now if you jet for the summer right. in the winter you should be running lean right? or rich? right now im really rich plug is soaked in gas and its black

Cold air = increased air density = need for more fuel = running lean in colder temperatures. If you are running rich in the winter temps you were running REAL rich in the summer and probably have an ass load of carbon build up lol.

I find myself jetting 4 times a year on the average or 6 times if the temperature changes are very gradual or hop up and down drastically - Spring (sometimes again in the transition from spring to summer temps), Summer, Fall (Sometimes again in the transition from summer to fall temps), and winter.

 

[xkingraptor350x]

wtf then... i got it back from the dealer and it was a nice brownish -tan couldnt ask for anything better ... and i know for a fact i wasnt running rich in the summer

 

[DeathShadow]

wtf then... i got it back from the dealer and it was a nice brownish -tan couldnt ask for anything better ... and i know for a fact i wasnt running rich in the summer

You can not really base your jetting entirely on plug color anymore... It's just science man, if you are running rich now then there is no way in hell (unless something else changed) that you weren't running even more rich in warmer weather. How do you know for a "fact" you weren't running rich over the summer? A O2/mixture meter is fact; plug colors, ass dynos, and guesstimates are theories.

Just out of curiosity, did you do a proper plug chop? Orrrrrrrrrrrrr did you start the quad, turn it off, and then pull the plug...

 

[xkingraptor350x]

right now my quad is taken apart by that i mean no plastics, battery, lights, nerfs .... things like that i iwas courious and pulled the plug and it was fouled to hell.... but i heard from a guy today that if you put to much oil in that could do it also.... and i did do an oil change and accidently put too much oil in.... and i siphoned some out and recheck my oil and it had still i little to much..... rode it for a while then it sat for like a week ..... then yesturday i pulled the plug for the hell of it and its fouled

 

[DeathShadow]

right now my quad is taken apart by that i mean no plastics, battery, lights, nerfs .... things like that i iwas courious and pulled the plug and it was fouled to hell.... but i heard from a guy today that if you put to much oil in that could do it also.... and i did do an oil change and accidently put too much oil in.... and i siphoned some out and recheck my oil and it had still i little to much..... rode it for a while then it sat for like a week ..... then yesturday i pulled the plug for the hell of it and its fouled

You must do a real plug chop.

 

[xkingraptor350x]

wtf is a plug chop???? lol is that taking it out and riding balls to the wall and then shut it off and pull the plug ?

 

[DeathShadow]

wtf is a plug chop???? lol is that taking it out and riding balls to the wall and then shut it off and pull the plug ?

Well to test out the main jet ur going to put a new plug in, let her warm up to operating temperature, go out and ride balls to the wall through the first 4 gears, at the top of 4th grab the clutch in and kill the motor gliding to a stop, take the plug out and check it.

 

[xkingraptor350x]

ahh i c

 

[yamarider]

I need to rejet mine for the colder weather. How many jet sizes larger should I start with? I never rejetted for the winter with my hondas so i'm not sure how much of a difference the colder weather makes.

 

[xkingraptor350x]

do you have the dyno jet kit? if so id say just go one more up

 

[yamarider]

yeah i got the jet kit... should i move the needle up too?

 

[xkingraptor350x]

possibly... there is just so many combinations you can do.. i think there are 5 stages in the dyno jet kit needle jet.. i would try just going up in the main one size and see wht color the plug is... i expect you know how to check your plug when your jetting

 

[yamarider]

i'm a little confused about that. I know that running full throttle and checking the plug gives an indication of the main jet, but what about the needle settings? Do I run at half throttle for the test, or do I just leave the needle position alone if it's running ok?

 

[xkingraptor350x]

i beleve you needle jet is for your very top end.... like 5-6 gear... main jet is like 4th gear toped out pull in the clutch... shut it off then come to a stop and pull your plug... and see wht it looks like

 

[ratchracing]

Posted by xkingraptor350x on Today at 6:55am
i beleve you needle jet is for your very top end.... like 5-6 gear... main jet is like 4th gear toped out pull in the clutch

thats wrong.... gear selection is irrelavent, main jet controls from about 3/4 to full open, the needle controls the 1/4-3/4 throttle position, this page explains it better than I can.....

http://www.off-road.com/atv/tech/fuel-exhaust.html#carb

 

[xkingraptor350x]

then im wrong.. not no jetting expert.. but im just going buy wht diffrent ppl have told me...

 

[xkingraptor350x]

wait isnt that for 2 stroke tho???

 

[ratchracing]

2-stroke, 4-stroke, they both follow the same general guide line as far as jetting, yes there are differences, but the different circuits in the carb work in the same way...... when jetting always think of the throttle position in relation to the carburetor circuit, not gear or speed