WTF???

Budget_Blaster

New Member
Dec 25, 2009
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Illinois
Ok so we went riding and a kid from town was out on his blaster basically stock besides the overbore of like .010 i mean bonestock down to the pipe just kicked my 240bbk's ass!!!!!!!

I know its in my jetting its still rich but i didnt know it was running this bad!!!

Ive got the stock needle back in it on the third position from the top of the 6 positions availible,a 340 main,and a 32.5 pilot.My air screw is barely a 1/2 turn out all this on a stock carb.

To worsen it my little brother just bought a blaster nothing specail only mods are an extended swing arm and a dg exhaust and his runs so much better than mine his is crisp and clean idling not choppy like mine and when it revs its literally like 3 times faster than mine and sounds so crisp.I know mines rich the plug stays kinda sooty looking and wet wheres a good ball park to start in?

Im in dire need of tuning help if a 15y/o kid on a stock blaster just spanked me please help!!!
 
Do you have an air leak, air screw 1/2 a turn out seems strange, at least 1 1/2 turns out for a good idle setting.

The idle circuit has quite a lot to say to the needle until you get to 1/2 throttle. If the idle is bad the low to mids could suffer as well.
 
airscrew 1/2 turn out for highest idle and best rev response??? is calling for a bigger pilot,
http://www.blasterforum.com/do-yourself-20/jetting-101-everything-explained-1625/

but.............
check out rtaylors thread, and grab that 34mm carb/boot, and the vf2's he has
that bbk is never gonna run to it's full potential on a stock carb
that fmf pipe isnt doing it any justice either, right bend for max power outta that thing

ya gotta spend the chedda if ya want it to run betta

rtaylors for sale thread.............
http://www.blasterforum.com/sale-18/blaster-part-out-43568/
 
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Ok so we went riding and a kid from town was out on his blaster basically stock besides the overbore of like .010 i mean bonestock down to the pipe just kicked my 240bbk's ass!!!!!!!

I know its in my jetting its still rich but i didnt know it was running this bad!!!

Ive got the stock needle back in it on the third position from the top of the 6 positions availible,a 340 main,and a 32.5 pilot.My air screw is barely a 1/2 turn out all this on a stock carb.

To worsen it my little brother just bought a blaster nothing specail only mods are an extended swing arm and a dg exhaust and his runs so much better than mine his is crisp and clean idling not choppy like mine and when it revs its literally like 3 times faster than mine and sounds so crisp.I know mines rich the plug stays kinda sooty looking and wet wheres a good ball park to start in?

Im in dire need of tuning help if a 15y/o kid on a stock blaster just spanked me please help!!!

BWAAHAAAAAA! Ok now that that's outta the way, do what Awk says, you need a bigger carb! If money is tight (i know that feeling), then at least jet that carb up! Id say you need a 45-48 pilot to start with, the stock needle clip may need to start on the 4th or fifth position from top. Then follow the jetting procedures to determine where to set the air screw, start at 1.5 turns out.
 
Well a new carb aint going to happen at the moment so id like to make this one work as best as possible.

Yea at 1.5 turns out the motors idling at like 4k rpm + where ive got it set now its right about 1700-1900 with and without the lights on.

And why would i jet up higher if im already too rich?or am i missing something?

Does anyone have a blaster with very similar mods to mine and if so whats your jetting at?

What does the jet needle do for idling?
 
Well a new carb aint going to happen at the moment so id like to make this one work as best as possible.

Yea at 1.5 turns out the motors idling at like 4k rpm + where ive got it set now its right about 1700-1900 with and without the lights on.

And why would i jet up higher if im already too rich?or am i missing something?

Does anyone have a blaster with very similar mods to mine and if so whats your jetting at?

What does the jet needle do for idling?

No one else who may have a big bore kit running on the stock carb is going to be any better off to offer you any help. A 26mm venturi is such a huge flow restriction your engine isn't able to purge the old charge out of the engine and it's basically overheating by burning each stroke with too much of the last stroke left in the cylinder.

I've said it before, I'll say it again. 2 strokes are like an orchestra.... everything has to be playing together for it to work right. It's not that the BBK stinks that bad, it's that your entire "winds" sections is asleep!
 
Well a new carb aint going to happen at the moment so id like to make this one work as best as possible.

1. Yea at 1.5 turns out the motors idling at like 4k rpm + where ive got it set now its right about 1700-1900 with and without the lights on.

2. And why would i jet up higher if im already too rich?or am i missing something?

3. Does anyone have a blaster with very similar mods to mine and if so whats your jetting at?

4.What does the jet needle do for idling?


I numbered them, in order:

1. It's gonna with a stock pilot! It's super lean at idle! Turning the lights on means jack sh*t!

2. You may be rich on the main, but not with the pilot or the needle!

3. NO!

4. Read belowVVVV
For Keihin carbs-
1he7lv.gif


For Minkuni carbs-
2e67qkh.gif
 
i was running my bbk with stock carb, needle 4 clip from the top, stock pilot, and 340 main, airscrew 1 1/2 out at 800 ft elevation.....i had boyeson reeds, bills pipe, and a uni....n mine was dead on and freakin ripped with that setup....i kno it wasnt to its full potentional but with that small ass carb yours should be crisp and snappy as hell....
 
a stock carb is a mikuni, and the stock 32.5 or a 35 should be in range

that being said, you want the bike to idle it's highest, wherever that may be with the airscrew, if it's 1.5 turns or 2.5 turns, then turn the idle adjustment down to adjust you idle

you do not adjust the idle of the bike with the airscrew !!!!!
it must be set to idle the highest
my guess is you have the pilot too rich with the airscrew adjustment
if it idles it's highest below 1/2 turn, i'd jump to a 35 pilot for the bbk, and see where that puts the airscrew, if over 2 - 2 1/2 turns out, return to the stock 32.5 pilot at 1.5 turns out, or wherever it idles the highest
once you get the pilot to idle and rev good/clean
then start all over again tuning the needle and main, the circut below will effect any and all circuts above, if the pilot or needle are rich, the main will be too

it is also possible to do plug chops with all 3 circuts, but the "idle the highest between 1/2 and 2.5 turns out method" has always worked for me
but a plug chop at 1/2 throttle is possible to tune that needle if needed
1/2 throttle into 6th gear run, pull the "brand new" plug, and cut the threads off to read the smoke ring, not the whole insulator color

after getting the pilot and needle correct, you can then move on to a 6th gear wide open throttle run/plug chop to get the main dead on

forget the main till the pilot then needle is correct
 
Ok i think i made a novice mistake...And may have seen the error of my ways due to awk.

Ok i have been using the a/f to set idle.

I got out and played with it for a few earlier and heres what i noticed i can get it to idle up higher like described and i think after some refreshing of the memory got the tuning aspect down or atleast headed in the right direction.

Heres what i dont understand...Ive got the motion pro idle set screw that goes in the stator side of the carb and it dont matter if i screw it in or out it makes no difference hell i can take it out and it still dont make a difference.I even swapped it onto my bros blaster and it did the same so i know it aint an air leak.

Ive got the hang of what i need to do to tune the carb but how do i lower the idle to the manuals setting of 1700?
 
sounds like the cable may be holding the slide open
is the cable adjusted too tight at the throttle ???
is it routed properly ???? ty-rapped to the frame too tight ????
is it pulled too tight right where it enters the carb ???
is the needle going down into the needle jet ???
is the oil injection deleted, including blocking off the oil injection inlet on the side of the carb ????
is the brass washer under the main jet ????

all things to look for
 
Ok i think i made a novice mistake...And may have seen the error of my ways due to awk.

Ok i have been using the a/f to set idle.

I got out and played with it for a few earlier and heres what i noticed i can get it to idle up higher like described and i think after some refreshing of the memory got the tuning aspect down or atleast headed in the right direction.

Heres what i dont understand...Ive got the motion pro idle set screw that goes in the stator side of the carb and it dont matter if i screw it in or out it makes no difference hell i can take it out and it still dont make a difference.I even swapped it onto my bros blaster and it did the same so i know it aint an air leak.

Ive got the hang of what i need to do to tune the carb but how do i lower the idle to the manuals setting of 1700?

Hope ya get it figured out! I assume alot when I answer questions, I always take for granted that everyone knows the basics, and that could lead to the wrong info at times like this.
 
Ill recheck the cable routing and yes the oil injections blocked off including the nipple on the carb.No it didnt come with the brass washer a but i had a washer in my tool box that was the same thickness and diameter as the oem.Ken actually caught that and steered me correct before the 240 blew up when i had all the tuning issues before.

Its cracking up top its just from idle to wot its seems soft for a modded 2 stroke.

But i think ive made some good steps towards resolving this we are riding tomorrow and ill have more time to tune.

Thanks guys god i feel like a dumb ass!!!
 
Dude.....the blaster gods are not going to be happy reading this thread. You best be working day and night to get your machine running right so you can start working your way back onto their good side with some beat downs. If it were me, I'd prolly skip the stock blasters and find some 4pokes to lay beat downs on. The gods seem to really like it that way.

just say'n.....
 
Ok first i want to say damn this thing is sick!!!!!!!

And second awk youre the man!!!My cable was zip tied too tight and not allowing me to idle down.So after i lined that out i set the a/f at 1.5 turns and it seems right on the money seemed to be where it idled the highest then i set the idle with the set screw from motion pro seems the reason it had no effects on idle was because of the cable.

But me and my bro went riding today and this thing walked all over his blaster and his is an ice racer and for what it is gets with it.Has a DG pipe/silencer,boysens/reed spacer,and keihin and for right now thats all we know.

Ive not done a plug chop yet on the new a/f settings but the plug went from black as the ace of spades and wet to a greyish look and not wet.I think it can be refined more but im leaps and bounds from where i was.

So to all you guys who respnded thanks even though finding out the problem (me making a dumb ass newbie mistake) was a little embarassing lol i say thanks i appreciate it.