For Those about to Rock... buying OKO Flatslides..

[corrin27]

Hey guys so after reading through all 28 pages and deciding i do want to put an OKO carbi on my bike i just need a bit of help with which one. Ive currently got a 125cc DUCAR GEN II with a 30mm big bore exhaust being the only changes ive made to it. ive also read through this post to see if i could find something similar.
http://www.miniriders.com/carby-tuning/24570-carby-settings-your-bike-7.html
Ive noticed majority seems to be 26mm OKO with jet sizes 36 and 98, although i also read somewhere a 24mm OKO would be better suited for my engine....just wondering which way i should go and if i was to go the 24mm what size jets and such i should be looking for as i dont know a great deal about this stuff but am learning alot from reading on here so thanks heaps guys

Cheers Daniel

 

[aussie_140]

My yx150 has been back firing heaps on a mikuni 26ml carb, so I replaced the jets but it is still doing it. Anyone know what it could be? Any help would be appreciated!

 

[barnzey]

I just installed flatslide carby 26mm on my dhz 160outlaw and since then have noticed smoke when accelerating could this be cause by the carby?

 

[aussie_140]

might have to get one

 

[timeeh]

I just installed flatslide carby 26mm on my dhz 160outlaw and since then have noticed smoke when accelerating could this be cause by the carby?

I would be guessing your valves..... but it is a guess, if anything a decent carby will backfire from too much fuel, but smoke generally relates to valves or a scored barrel, OR if your mixture is too rich, however if it's that rich your plug should be black. (feel free to correct me if i'm wrong, iv'e had a few beers and could be talking sheet)

 

[Cooter]

Hi all
I know it's a bit left field but I have a2001 ktm 65 minibike that I've fitted an oko 26mm flatslide to and boyesen reeds. Boyesen recommend a 210 main jet and 30 slow jet.

My question is that's with the mikuni carb, how does this relate to the oko jet sizes? Can anyone recommend a decent "range" for me to start looking in for adequate sizes.
The bike starts and runs but is very sluggish when opening the throttle, it runs very well with the choke on though so I assume it's running too lean.

Any helps appreciated
Cheers
Craig

 

[THUMPINOZ]

Take the OKO off it, That is going totally backwards with the engine running a 9Small in comparison) 4-stroke carb on a 2-stroke, Why did you remove the stock KTM carb?

 

[Cooter]

Actually the oko is bigger. Standard ktm carb is a mikuni round slide 24mm as opposed to the 26mm I put on it. It definitely makes more power and has better midrange but the tuning isn't right. I just want a reference as to what jet sizes are similar to a 210 mikuni jet. Also read somewhere that the oko's were originally designed for 2 strokes and adapted to 4 strokes

 

[THUMPINOZ]

What is the inlet outlet sizes on the OKO & the KTM carbs?

Yes the OKO is actually a copy of the Keihin carbs but as you mentioned the OKO is adapted to suit the 4-strokes, You may get it to work but I just dont think you will get the OKO to perform on a KTM65, You shoulda researched first, Try out a YZ80 carb, Much better quality & probably easier to sort out the jetting>

yz 80 carb on ktm 65......

 

[Cooter]

Yea I did do alot of research into it. The yz80 carb is the same 26mm as the oko. Yea quality is prolly a lil less but it's not a high end racer, just my pitbike. It's only a 2mm increase over the standard carb but the response and mid are much better. I'm fairly certain with the right jetting it'll be great.

Sooo back to my question, anyone got any idea bout jetting comparisons between mikuni and oko?
I did find a chart on here that has comparisons between mikuni and keihin but had nothing on oko.

 

[krazed0451]

The OKO will be fine for a 2t, you may notice on their site that they actually list a heap of 2t bikes...

There is a jet size comparison sheet kicking around on the site somewhere but I'm at work at don't have the time to do a trawl at the moment. Hit up the search function and see if you can track it down

 

[Cooter]

Hey yea I'm pretty sure it'll work fine with the right jets
I've actually been running through page after page on this for a while. I've found the conversion charts but am still lost.
It all comes down to the boyesen site recommending a 210 main with a 30 slow. Everything I've read seems to state that's a keihin number not a mikuni. Whereas the standard carb on the 65 is mikuni.
KTM JETTING - TECH CENTER

What I can't work out is if the boyesen site has just stated a keihin value. The biggest oko jet I could find for sale is a 120 main. So leaves me confused because I thought the oko jets were same as keihin.

 

[my67xr]

im guessing you are running the short round jets?

this guy has lots available, ex UK, eg-
Keihin FCR CV CVK PD VB VE VA Main jet 99101-393 #170 | eBay

most motorcycle tuners can get them if they dont have them in stock.
i use Show and Go Motorcycles in adelaide, they keep sizes 60-200 in stock most of the time.
Team Show and Go Australia

 

[Cooter]

Hey nah it runs the hex jets. It's currently running a 100 main and a 36 slow. Maybe anyone have any ideas on a ballpark to head to with oko sizing?

 

[my67xr]

hex jets 142-180 ,
SET 10x MAIN JETS for PWK Arreche OKO Carbs 142-180 | eBay
or single jets,
pwk jets | eBay

or as above, show and go.

 

[zwebx]

what if my motor has a 30mm inlet valve in it?
go for the 30mm oko?

 

[gottagetacheaperhobby]

hey guys i no this is a old thread but i thought beter to bring this one back up than start another..... i recently brought a 24mm oko to put on my gpx125 have changed the jetting to 96 main 34 pilot but i cant get it to idle properly and it runs better with the choke on.... any one have any ideas as to wat ive done wrong? the thing ran better with the mikuni (idle wise anyways)............ should i have bought the 26mm maybe?

 

[8r3nd0]

I've got a 24mm oko working awesome on a 140 so I reckon you can get it there.
I'd say up the pilot to a 36 because from memory the choke on these carbs are actually an enricher so in theory will make it better.
Just as a reference I'm running the stock 36/100 setup on the 140 and its mint.
You've tried adjusting the mixture and rev screw together.

 

[gottagetacheaperhobby]

yeah man ive played and played with idle and mixture screw.... i just found the vid explaining the enricher choke which i had no clue about so yeah i guess its to lean of a pilot... i cant do accurate plug chop either as i got no front wheel on it atm (doin fork swap)

 

[my67xr]

does your OKO 24 have the Powerjet on it?
if so, disconnect and block it off until you get the pilot, and main jetting sorted.