I'm building my top end and I want to go on the safe side so I don't have to do it again anytime soon so I'm really thinking about going from the stock 230 to a 250.now all I'm doing is going. 080 over and maybe drilling a 2 inch hole in the lid of the air box.the only other thing that is done to the quad is a fmf silencer.is this going to run way too rich? Should i stay with the 230,and if I go with the 250 will I need to move the clip on the slide in the Carb or will it be fine to leave it alone.I'm going to run pre mix 93 octane 32:1 so what should I do to be safe from a blow up?
jetting up
- Thread starter blastblast
- Start date
#250 TO #260 should suit fine depending on elevation and temp, but please confirm by doing a plug chop.
Leave the needle where it is, and adjust the idle before you plug chop.
Idle adjust proceedure.
Start with air screw 1.5 turns out.
Set idle screw so that it has some sort of idle.
Warm up motor and then set idle screw for a fast idle.
Adjust air screw either way to get the fastest idle.
Adjust air screw a little at a time leaving 10 secs to allow the motor to respond.
Re adjust idle screw for desired idle.
Plug chop.
Warm up motor to operating temp.
Fit new B8ES plug, ride through the gears and hold WOT in 5th or 6th gear for 10 seconds, or as long as you can safely.
The idea is to get the motor pulling hard for as long possible up to 10 secs.
Switch of the motor and pull in the clutch, roll to a stop.
Take the plug out and replace the old one for the ride home.
Carefully cut the threaded end off the plug to expose the insulator.
There should be a smoke ring of a cardboard or biscuit colour around the insulator.
If it is non existant or a very light colour, you are lean and require a larger main jet.
If it is a lot darker you are rich and may go down a size in main.
I prefer to run a little on the darker side, I may loose a little power but it is worth it for the peace of mind that I won't need a rebuild so soon.
It may be a better idea to pepper the air box lid with a multiple dose of smaller holes.
Leave the needle where it is, and adjust the idle before you plug chop.
Idle adjust proceedure.
Start with air screw 1.5 turns out.
Set idle screw so that it has some sort of idle.
Warm up motor and then set idle screw for a fast idle.
Adjust air screw either way to get the fastest idle.
Adjust air screw a little at a time leaving 10 secs to allow the motor to respond.
Re adjust idle screw for desired idle.
Plug chop.
Warm up motor to operating temp.
Fit new B8ES plug, ride through the gears and hold WOT in 5th or 6th gear for 10 seconds, or as long as you can safely.
The idea is to get the motor pulling hard for as long possible up to 10 secs.
Switch of the motor and pull in the clutch, roll to a stop.
Take the plug out and replace the old one for the ride home.
Carefully cut the threaded end off the plug to expose the insulator.
There should be a smoke ring of a cardboard or biscuit colour around the insulator.
If it is non existant or a very light colour, you are lean and require a larger main jet.
If it is a lot darker you are rich and may go down a size in main.
I prefer to run a little on the darker side, I may loose a little power but it is worth it for the peace of mind that I won't need a rebuild so soon.
It may be a better idea to pepper the air box lid with a multiple dose of smaller holes.
