Page 2 of 6
Jetting down procedure?
Posted: Wed May 02, 2012 3:53 am
by Madman
Bear45-70 wrote:Listen to baka. Veedub doesn't know half what baka knows.
thanks bear I'll do so!
Re: Jetting down procedure?
Posted: Wed May 02, 2012 6:07 am
by bakaracer
you dont have to go on a 1mile ride to see if the main is to small. just down the block you can tell
Jetting down procedure?
Posted: Wed May 02, 2012 6:42 am
by Madman
Just for more information to assist any advice I'm running a 50mm BBK boost port matched intake bored out with 21mm oko v8 typhoon pipe!

Re: Jetting down procedure?
Posted: Wed May 02, 2012 12:48 pm
by veedubh20
ussa bear is heavy than me, Haha!
baka is heavy than me too.
tuning may vary on rider weight ride scooter with the motor setup / jetting.
heavy rider need more fuel feed into a 21mm carb.
grams weights need to play around .
20 % daytona spring is very stiff spring, need more fuel on the main jet.
boost port need more fuel on boost port case and 50mm bore on wide open throttle ( after motor break in)
Jetting down procedure?
Posted: Wed May 02, 2012 1:08 pm
by Madman
veedubh20 wrote:ussa bear is heavy than me, Haha!
baka is heavy than me too.
tuning may vary on rider weight ride scooter with the motor setup / jetting.
heavy rider need more fuel feed into a 21mm carb.
grams weights need to play around .
20 % daytona spring is very stiff spring, need more fuel on the main jet.
Thanks man I appreciate your input I'll let you know how it turns out! And post more questions! I'm fat too 90kg lol.
Re: Jetting down procedure?
Posted: Wed May 02, 2012 1:16 pm
by veedubh20
Im like 45kg.
well you just dont want to light seize on 50mm bore. it very common on main jet , not set correct on a ball park.
Re: Jetting down procedure?
Posted: Wed May 02, 2012 10:02 pm
by bakaracer
veedubh20 wrote:Im like 45kg.
well you just dont want to light seize on 50mm bore. it very common on main jet , not set correct on a ball park.
your not no 99lbs person. Who you foolin
Re: Jetting down procedure?
Posted: Wed May 02, 2012 10:05 pm
by bakaracer
Madman how's this then,try a 120 main. That's about a size for a 24mm carb jetting with the 48 pilot and see how it runs. Since veedub insist that the jetting I suggested is to small.
Jetting down procedure?
Posted: Wed May 02, 2012 11:30 pm
by Madman
I'll do both and provide plug chop photos this will settle the debate and confirm who is correct but I think mr Baka has a $hit load of experience and that most any difference will be due to climate, and veedub as I said I appreciate any input! And plug chop will be coming soon!
Re: Jetting down procedure?
Posted: Wed May 02, 2012 11:56 pm
by bakaracer
keep in mind that on these bikes , its hard to get a really accurate plug chop since there is no clutch lever to pull in so when you kill the engine it stops right away.so the more the engine is turning the more the plug chop for wot will be not accurate.so the faster you can come to a stop safe the better the more accurate the plug read will be. plus you can tell also by feel and sound if the carb is to rich too so adjust jetting before doing a plug chop. again the jetting can be check with just a short ride down the street and back. no need for a 1 mile ride. if the bike is running crappy, dont waste a new plug on a plug chop. keep adjusting till it feels better then do a plug chop. if not your going to need a whole box of plugs.
Jetting down procedure?
Posted: Thu May 03, 2012 9:35 am
by Madman
Ok some progress. 21mm carb jetted at 48/120 (how do I type a fart sound)! 45/115 ran but bogged bad! 42/110 ran well up to half then bogged 42/108 ran ok but not much power and or speed stopped there on that carb!
Ok 28mm OKO 52/150 ran super but was way hot I think! 52/155 bogged
This is harder than I thought it would have been but Mr Baka you are not as stupid as your name suggests(Baka in Japanese means stupid) you were on the money with where to safely start on the 21mm!
Sorry veedub but not sure what happened there but wow you made it confusing for me!
So the result is I think the 21mm may be too small to take advantage of the BBK I put on! Will try more tuning on it but the 28mm is night and day in comparison!
Re: Jetting down procedure?
Posted: Thu May 03, 2012 10:08 am
by Mystic
first find the right pilot probably a 48 or 45 on the 21 THEN work on your main. YOU will have to move the clip on the needle up to lean down to richen the mixture once you get the main right to get a smooth transition through the ranges. Your temp guage will give you an idea if the jetting is right
Re: Jetting down procedure?
Posted: Thu May 03, 2012 9:43 pm
by bakaracer
Madman wrote:Ok some progress. 21mm carb jetted at 48/120 (how do I type a fart sound)! 45/115 ran but bogged bad! 42/110 ran well up to half then bogged 42/108 ran ok but not much power and or speed stopped there on that carb!
Ok 28mm OKO 52/150 ran super but was way hot I think! 52/155 bogged
This is harder than I thought it would have been but Mr Baka you are not as stupid as your name suggests(Baka in Japanese means stupid) you were on the money with where to safely start on the 21mm!
Sorry veedub but not sure what happened there but wow you made it confusing for me!
So the result is I think the 21mm may be too small to take advantage of the BBK I put on! Will try more tuning on it but the 28mm is night and day in comparison!
so basicly no matter what jets you tried the engine bogged. so when you used the 28mm with 52/150 ,did the engine bog too at some point? explain the bogg the engine is doing. everyones explenation of engine bogg could be from either carb issue or a trans issue which can get confused all the time.
Jetting down procedure?
Posted: Fri May 04, 2012 12:00 am
by Madman
This morning
52/150 ran well but too hot in the pilot range so I swapped in a 55/150
Then bogged into main so swapped in 148 and a little better so raised the clip on needle and better transition into main, but not very responsive.So raised the clip on needle again and it was much more responsive but still a little more to go, think next I will lower the main jet to a 145 and reset the needle and go from there! The bog is engine bog not transmission bog!
Oh here is the plug at my last setting.

Re: Jetting down procedure?
Posted: Fri May 04, 2012 12:03 am
by bakaracer
lets see more inside the plug more . the top of the plug read means nothing by its self. what plug is that? when you mean it ran hot in the pilot, are you talking about throttle area? the pilot is from 0-1/2 throttle but mostly 0-1/8th is where its more sensitive. then its the needle that takes care mostly with the pilot and main over lapping. how are you checking if its hot?