Change jetting if changing exhaust?

[blasterdubai]

Hi, I have a 2005 yamaha blaster and its currently in the wrokshop getting these things done: Porting and boring, vforce, bigger piston, jetting, and k&n filter.
But they're doing the jetting on the STOCK exhaust and i just ordered a TOOMEY exhaust and fatty pipe.
Do I have to alter the jetting if im changing the exhaust?
Thanks

 

[Zwiser]

yeah you have to change it but you should get a bigger carb like a 30mm oko or 35 pwk

 

[brandoz28]

the jetting has to be changed ANY time you modify airflow in or out of the motor

 

[acezeesawtooth]

i wouldnt go 35mm carb unless you are getting a big bore a 30mm oko will do you wonders. and yes you need to jet.

 

[blasterdubai]

yeah you have to change it but you should get a bigger carb like a 30mm oko or 35 pwk

I will try and get a oko 30mm but what happens if i keep the carb stock and dont change the jetting when i get my new exhaust?
P.S Is it ok to keep the OIL INJECTION even though your bike has a high performance engine?)
Thanks

 

[acezeesawtooth]

no i would dump the oil injection. there is a diy thread to show you how to do it for like 3 bucks. and if you dont change jetting (no matter what carb you get) your blaster will either be lean or rich. if its lean it will fry your engine, if its rich it will foul your plugs and clog your engine with the left over oil that isnt burning properly

 

[super noober]

its always a good idea to ditch the oil injection just to be safe. with the mods you listed off on a stock carb im guessing you will be in the 320 range. you really are not doing too much to the motor so i think a stock carb will be ok but again, nothing wrong with upgrading a little I:I I:I

 

[blasterdubai]

Why? I dont get it how come everyone says remove the oil injection?
But then i read a topic talking completely about oil injection and it said that theres nothing wrong with it...
Anyway im gonna keep the oil injection because if I do try change it to premix it'll probably get messed up..
Anyone got problems with oil injection???

 

[sc0r1a]

No need to upgrade your crab if your just riding around your property but you will definitely need to rejet for the exhaust.

I had an oil injector fail on me after i road it 3 times after a rebuild and ended up cost me 500+ to redo the whole 4 wheeler. Its pretty easy to premix get a 5 gallon gas can and a 20oz pop bottle (empty the bottle and clean it) then fill it with 2 stroke oil and dump into the gas, i believe thats how i did it, been a while since i had the quad, the new one i'm building is going to be premix that way you dont have to worry about anything.

 

[blasterdubai]

No need to upgrade your crab if your just riding around your property but you will definitely need to rejet for the exhaust.

I had an oil injector fail on me after i road it 3 times after a rebuild and ended up cost me 500+ to redo the whole 4 wheeler. Its pretty easy to premix get a 5 gallon gas can and a 20oz pop bottle (empty the bottle and clean it) then fill it with 2 stroke oil and dump into the gas, i believe thats how i did it, been a while since i had the quad, the new one i'm building is going to be premix that way you dont have to worry about anything.

Ya but whats the ratio for the blasters premix??

 

[stabor1122]

Why? I dont get it how come everyone says remove the oil injection?
But then i read a topic talking completely about oil injection and it said that theres nothing wrong with it...
Anyway im gonna keep the oil injection because if I do try change it to premix it'll probably get messed up..
Anyone got problems with oil injection???

I am running 32:1 premix in mine. I bought a RatioRite Measuring cup. Was like 10 dollars. Has lines for all the different ratios and for different number of gallons. Super easy. You can't mess it up (if you do the you shouldn't be riding a 2 stroke....lol). The biggest problem with the oil injection is you usually dont know it isn't working untill it is too late and you have blown your engine.

 

[CarGuy420]

you are better off without your oil injection. dont leave mixing gas up to a computer, you should know exactly what mixture is in your tank.
And yep, do the jets for sure. any time you upgrade fuel/air (in or out)/spark your carb needs to compensate fuel delivery for that