who has jetted like this

[89blaster89]

has anyone else jetted by throwing in a jet they think is to big and riding to see if its blubbering or sputtering from being to rich then going down in jet sizes until it doesent sputter or blubber? it may still be rich but its ok to be a little rich it doesent hurt anything but take a small bit of power.

 

[blasterboy32]

i use to do that until i blew a top end from running lean. now i always do a plug chop

 

[brandoz28]

start too big, then plug chop till it's right....

 

[89blaster89]

i would plug chop but i have NOWHERE to do one

 

[Surfrjag]

i have done it like that. i dont see how you would blow it up like this..

 

[brandoz28]

you could do it this way, but you're always going to be guessing about where you're at

 

[89blaster89]

i have done it like that. i dont see how you would blow it up like this..

exactly how can it blow from being lean, i would just have it one jet size under from sputtering and blubbering thats rich not lean

 

[blasterboy32]

I'm just saying its not accurate and there's a lot of margin for error

 

[Braaaptor]

Nothing wrong with this approach. You just have to be sure to do plug chops and not be left guessing at whether you're rich or lean overall. A lean bog can easily be mistaken for a rich burble by an inexperienced tuner, and this can lead to a blown top end. I'm good at jetting carburetors myself, but I still dont take chances by not chopping a plug or two after an initial carb set-up or re-jet. Better safe than sorry.

That said, since I run a Mikuni TM 34 carb on my Blaster and few (if any) other people on here do the same, I had to guess what sizes to use when first jetting. I went rich and was safe.

 

[98blaster+4]

the way your doing it is the way many people do it, its not wrong, as long as you know from the first jet that its rich and not lean. you must do a plug chop at the beginning and end of jetting if you really want to be sure. unless you have been jetting things for a long time and know exactly that your rich not lean, plug chops are important.

 

[89blaster89]

yes i know there important but i will be dropping in a 320 main in my blaster and with my mods that will be most likely very rich and sputtering and then if it sputters im going to put in a 310 and if it dont sputter i will leave in the 310

 

[98blaster+4]

whats your elevation ? you should be at least 320 with youre mods

 

[89blaster89]

whats your elevation ? you should be at least 320 with youre mods

ive heard only around 290 and im about 350 feat above sea level

 

[Blaaster]

Been there, done that, but you have to be sure that you are running rich with the first jet.

As discussed, the only way that you can be sure where your jetting is at, is by plug chopping.

That said, one jet down from a babble, blubber or fourstroking, is a pretty safe bet.

 

[89blaster89]

Been there, done that, but you have to be sure that you are running rich with the first jet.

As discussed, the only way that you can be sure where your jetting is at, is by plug chopping.

That said, one jet down from a babble, blubber or fourstroking, is a pretty safe bet.

i have sizes 270- 330 size jets so i should drop in a 330 and i will def be running rich right?

 

[Blaaster]

#330 should put a FMF with no air box lid, enough on the rich side.

The motor should sound like the choke is on.

Remember, if something goes wrong, everyone has recommended doing a plug chop.

Pease sign the disclaimer ......................................

Thank you.

 

[89blaster89]

#330 should put a FMF with no air box lid, enough on the rich side.

The motor should sound like the choke is on.

Remember, if something goes wrong, everyone has recommended doing a plug chop.

Pease sign the disclaimer ......................................

Thank you.

ah you just made me all scared now to put in a really rich jet...i would plug chop BUT I HAVE NOWHERE TO DO ONE!! putting in a rich jet wont hurt the motor though right?

 

[mjgnslngr]

I'm at 350ft asl, full fmf fatty exhaust. Pretty much stock motor. 280 main, 32.5 pilot, needle in the middle. I'm with Blaaster, please sign disclaimer or PLUG CHOP! If not, I'll be looking for you in the 'WTF HAPPENED?" thread!

 

[89blaster89]

I'm at 350ft asl, full fmf fatty exhaust. Pretty much stock motor. 280 main, 32.5 pilot, needle in the middle. I'm with Blaaster, please sign disclaimer or PLUG CHOP! If not, I'll be looking for you in the 'WTF HAPPENED?" thread!

ive tryed to do a plug chop and i got 4th gear WOT and thats as far as i got i nearly flipped my quad off a cliff trying to do so. it had 300 main with 32.5 pilot clip in the middle i got a light paper bag color, so if i put in a 330 im pretty sure it will be rich and 4 stroking and blubbering, i will then go down in jet sizes till it doesent blubber or 4stroke anymore and leave it there, then i will try to do a plug chop and im doing it going up a windy curvy bumpy gravel driveway 1/5th a mile long, so if i dont come back on here you will know why i will probally be in the hospital due to falling off a cliff.

 

[Blaaster]

ah you just made me all scared now to put in a really rich jet...i would plug chop BUT I HAVE NOWHERE TO DO ONE!! putting in a rich jet wont hurt the motor though right?

Puttin in a jet which is too rich will make the motor run terrible, and will foul plugs. It can also produce a lot of smoke.

You will not fry the piston from overheating, as fuel acts as a coolant.

Continually running rich will add to carbon deposits, and spooge coming from the exhaust, but should not kill the motor.