jetting, premixed open air box, .040 over.

[duneracerweston]

well i finally figured out the electrical on the 03, (ignition source coil was weak) and went to do the break in, at first it was great just the avg blaster, then it did a classic 2 stroke run away, well i let it set thinking it could have just drained the carb, but when it fired again it ran away then too, so i got to looking and i dont think the joker that had this machine before me jetted it for 32:1 premix and a open air box!

so whats a good base line for converting to premix? the last blaster i had was already on pre mix but it is long gone to reference from.. any help is appreciated!

 

[JonS]

well, stock jetting on the main is 230. some guys on here may bump up from the 230 to 240 for pre-mix, i wouldn't, but since you have an open airbox it may be that you need a couple sizes up. i don't think bore size affects jetting either.

does the bike have an exhaust on it too?

 

[Surfrjag]

most of the jetting will be in the main jet. if your having rpm run away then you either have an air leak or something causing a lean condition (partially clogged pilot jet) or clogged petcock. be sure and check that your gas cap is venting properly as well. Your slide may be being pulled up like a high idle as well. i would check the cable to make sure its not binding up, try adjusting the idle and air screw. then i would clean the carb, mainly the pilot jet. Then i would proceed with an airleak test. once you get the idle down then you can worry about the main jet. post your mods and we can get you close.

 

[duneracerweston]

open air box, K&N, thats it its all stock, i di just finish the motor, it doesnt have a air leak around the carb ive checked there, do you think it could be the new vito's crank seals? i was going to re jet after break in but it wont finish break in running like this! also it has a tors but its unplugged because it wouldnt spark plugged up.

 

[JonS]

open air box, K&N, thats it its all stock, i di just finish the motor, it doesnt have a air leak around the carb ive checked there, do you think it could be the new vito's crank seals? i was going to re jet after break in but it wont finish break in running like this! also it has a tors but its unplugged because it wouldnt spark plugged up.

maybe think of 2 sizes up on the main then. also, just because it's not leaking around the carb doesn't mean it isn't leaking elsewhere. the cases could be leaking, base, head gasket, crank seals, etc.

btw, vitos crank seals suck balls as the majority up here will tell you. OEM or Wiseco work best. maybe a couple other brands that i can't recall.

first and foremost let me recommend that you get a good leak down tester if you haven't already. every 2 smoke owner needs one in their tool box.

 

[slickerthanyou]

well i finally figured out the electrical on the 03, (ignition source coil was weak) and went to do the break in, at first it was great just the avg blaster, then it did a classic 2 stroke run away, well i let it set thinking it could have just drained the carb, but when it fired again it ran away then too, so i got to looking and i dont think the joker that had this machine before me jetted it for 32:1 premix and a open air box!

so whats a good base line for converting to premix? the last blaster i had was already on pre mix but it is long gone to reference from.. any help is appreciated!

open air box, K&N, thats it its all stock, i di just finish the motor, it doesnt have a air leak around the carb ive checked there, do you think it could be the new vito's crank seals? i was going to re jet after break in but it wont finish break in running like this! also it has a tors but its unplugged because it wouldnt spark plugged up.

Ok, when you say you unplugged the tors on the 03 did you do it this way?- http://www.blasterforum.com/do-yourself-20/03-06-tors-removal-diy-41973/

Most of us run 32:1 as it works well. Air leak test will tell ya if it's air tight or not! I have nothing against Vito's crank seals. It's the cylinder base gasket that we recommend stock steel or cometic est! Stay away from thin paper green (especially), brown black, grey, all cheap junk.

 

[Blaaster]

Moving from oil injection to 32:1 requires that you increase the main jet one size.

Due to oil taking the place of fuel in the mix, you will be running with a leaner mix than optimal, this can cause a slow but sure demise.

An open air box calls for at least two sizes increase in main jet size. You should be running at least a #270 - #280 main jet.

Confirm jetting with a plug chop.

The 2 stroke runaway concerns me, do not run again until you have done a leak down test, air leaks can quickly kill a motor.

 

[duneracerweston]

for the tors all i did was the two under the hood, so ill do the carb end as well.

ok so 270 as a base line.

ill get a leak tester, i dont plan on running it till i check for a air leak.

 

[Blaaster]

It would be safer to start at #280 and plug chop with a b8es plug and work back if you have to.