New member/need some break in jetting help

2L8

New Member
May 15, 2013
11
0
0
Hey, I'm new to blaster forums. I bought my wife a 99 Blaster that had a blown top end due to previous owner cutting and plugging the oil injection lines and improperly mixing the gas. I am pretty mechanically inclined, however I never made any jetting changes to any carb. The quad has a stock carb, stock jets, uni air filter, stock exhaust, air box lid on, hot rod crank, the jug is getting bored to 68mm (.080 over) with a wiseco 68mm piston, it has a hotrod crank, and will also be getting boyesen pro series reeds (stock cage) due to wear/small chips, the tors system is intact with no plans to remove, and I will be correctly blocking and removing the oil injection because it is cheaper than replacing the lines and the oil pump is still a question mark if it functions properly. I will also be mixing the gas 32:1. I was wondering if the oil in the gas would cause a need for a change in jetting? I want the quad to break in properly so i don't have to spend the money to rebuild it for a while. I don't plan on going crazy with this quad, just something reliable for my wife to ride.
Sorry for the novel and thanks.
 
the stock carb's pilot jet (32.5) and needle on the middle clip will be just fine, even after break-in
the stock 230 main jet really doesn't come in to play while doing the heat cycles.... light revs to full temp, let cool completely, repeat 3 times, then re-torque head/base nuts.

but for short full throttle runs during a tank or 2 break-in period, i'd jump 1 main jet size (240) for the uni filter
and some say + 1 size more (250) for mixing versus injecting. ?

here's some info, in order as they should be done:

it should first be leakdown tested...
http://www.blasterforum.com/do-yourself-20/build-use-leakdown-tester-10663/

airscrew settings...
http://www.blasterforum.com/carburetor-138/adjusting-your-airscrew-pilot-jet-51060/

heat cycles/ break-in......
http://www.blasterforum.com/engine-13/blaster-engine-break-44174/


http://www.blasterforum.com/engine-13/la-sleeve-ct-racing-recommended-engine-break-50702/

plug chops for main jetting...
http://www.blasterforum.com/carburetor-138/how-plug-chop-53237/
 
Excellent info, I already got a leak down tester that will be done before it gets started. Also I knew about chopping the plug but it is nice to be able to compare to pics on this forum, and your write up on the airscrew was very helpful and easy to understand.
 
Excellent info, I already got a leak down tester that will be done before it gets started. Also I knew about chopping the plug but it is nice to be able to compare to pics on this forum, and your write up on the airscrew was very helpful and easy to understand.

you are well on your way to a top notch running blaster for the wifey I:I

btw...welcome to BF !
 
So i did the heat cycles fine, tried a 250 jet and it was rich so i put the 240 jet and got the carb tuned in pretty good. I took the quad on its maiden voyage like 5 mins ago and it rode ok except when holding the gas a little bit at idle or at slow ride and it starts missing like crazy. Is it a timing issue? Can that even be adjusted?

So I moved the clip on the needle one setting richer and it made a world of difference, however I still think it could run better. I will do the plug chop as soon as it is broken in enough to go WOT
 
Last edited: