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

[thump*140]

i'd go the 26mm over a 28 for a 75cc engine... depends on the breathing capabilities i'd imagine... maybe even a 21mm...

 

[Hillz]

yer gay, coz i have 28's & 30's may have to order in some small ones

 

[thump*140]

ah ok. yeah i dont think even a bored and ported 75 would breathe enough to warrant a 28mm... would have epic top end sting to it, but doughy as ***** down low.... would be real tricky to get the dead spot out of it as well...
time MR **** orders in some cheap smaller diameter okos methinks...

 

[krazed0451]

i believe the OD is 48mm.

Mate, if you where a woman I'd kiss ya, as it stands you'll have to settle for a wink

But seriously, you're a wealth of information!

 

[dylusion]

Hey Guys...

First post, and hoping someone might have some ideas for me to try out!

My other bike is a late model R1, which obviously is EFI and as such haven't had much to do with carbs before the last two days!

Bike and setup...

Lifan 125cc
OKO 26mm flat slide
Main: 100
Pilot: 36
Needle: E-clip on middle setting
Mixture screw: 1 1/2 turns out from seated

I have fitted up the OKO no drama's, had alot of difficulty starting the engine, pulled out the plug to check for spark, yep, plenty of spark, however i did note the plug was really wet!

Got the bike running, warmed it up, took it for a blast and did a plug chop, perfect tan colour and the bike feels stronger then ever in the top end.

So my problems, not sure if they're linked, or being caused by seperate issues, hoping someone can tell me;

1. When cold, bike is near impossible to start, engine getting waaayyy too much fuel. Once its warm, starts first kick easy as pie. (when i'm am trying to start on a cold engine i am not using any choke... figured it was a waste of time, already too much fuel...)

2. On a warm engine, from idle if i just crack open the throttle the revs pick up a tiny, tiny bit then just bogs, i back the throttle off abit, revs pick up, once they do, i can go WOT and its all good..., however if from idle i roll on the throttle smoothly/slowly/gently the revs pick up seamlessly...


Any one got some ideas where i should look first, happy to go and buy jets, but if its just a needle setting, no point!

Cheers, Lucas.

PS: can someone tell me if the mixture screw circled in the below pic adjusts air or fuel... if one or the other, does this carb have a screw for both fuel and air?

 

[thump*140]

easy one this one...
Main jet is too big... Running an OKO26 on a 125, you need a #92 or #95 main jet at the biggest...
36 pilot is borderline too big, but should be ok...

One of the strange idiosynchrasies of the OKO's, is that if the main jet is too big, it severely effects jetting elsewhere... ie: makes it seem like either the pilot or needle is way out...

try a smaller main, that should clean up the starting issues...

I believe the air/fuel screw meters air intake... Sean01 can probably confirm that one though...

 

[DvDRip]

yea screwing it out means more air, more lean ... and with the oko's you usually can't just snap them wide open from idle, you neeed to learn throttle control

 

[Jmo]

Just a quick one. I have a oko 26mm just installed on a yx140. having same difficult to start probs as mentioned above with K102 main (although i still have the ****** IRK which i understand wouldn't be helping). Thing is, I went to a local bike shop and tried to match up main jets. I ended up with a "95" (only thing stamped on it) main looking almost exactly the same as the original (same hex shape, length, thread diam etc). However, it doesn't have the "K", is an odd number (95 - not even, like the okos seem to be) and it doesn't have a slightly tapered edge to the jet hole as the original. I think it is a keihin main jet. Can someone please say if the "95" main as described will be ok for the oko and if the hole size is relative to the K102 version (ie, suitably smaller, to suit the unmodded yx140)? cheers

 

[krazed0451]

Can someone please say if the "95" main as described will be ok for the oko and if the hole size is relative to the K102 version (ie, suitably smaller, to suit the unmodded yx140)? cheers

Read Thump*140's sig

 

[Jmo]

thanks krazed. got it. i also re-read thumps post and it pretty much confirms it will be right. being a noob, just didn't want to think I had the right jet and then be thinking wtf it seems to be running rich/lean... i was confuzed due to the slightly different shape to the jet hole mainly. this obviously doesn't matter. cheers

 

[krazed0451]

No worries Jmo, enjoy the carb

 

[dylusion]

Cheers for the response Thump!

I will go about throwing a new main in and will report back.

Lucas.


Edit: on a side note, i was reading elsewhere on the forum about fuels... and for the first time since putting the oko on the bike i put 98 in it, could this make things alittle harder with starting? Any way, i have tomorrow off, so i will be throwing the smaller main jet in and see how it goes.

 

[SunnyCoastRider]

hey thump what sises is on your fym upping mine and a few other things

 

[sean01]

look in the other carby thread, it has everyones carby size and jet settings

 

[brad199]

hey thump how ya goin i got an oko on my 150 an irk and twin pipes and it run starts fine the only drama is i have to turn the idle csrew a tiny bit in untill it heats up or its prone too stall...any suggestions or just deal with it because changing the setting makes it run poorer or high idle..maybe aftermarket coil or lead? cheers

 

[thump*140]

hey thump what sises is on your fym upping mine and a few other things

Hey sunny, i'm not actually running an OKO in my FYM anymore, only had that to get it running.... It's currently running a Keihin Replica PE-24 roundslide, which i'm massively impressed with... Jetting is K35 pilot, and a K92 mainjet.. not sure of the needle though... it's unmarked...

hey thump how ya goin i got an oko on my 150 an irk and twin pipes and it run starts fine the only drama is i have to turn the idle csrew a tiny bit in untill it heats up or its prone too stall...any suggestions or just deal with it because changing the setting makes it run poorer or high idle..maybe aftermarket coil or lead? cheers

Hey Brad, i'd say your issue is more to do with the IRK... I've got the same problem with the Bling40, it wont idle unless you set it quite high... which makes it run hot, and poor response off idle like you're finding..
Best solution would be to change your IRK to an ORK... that will give the motor enough flywheel weight to keep the engine idling..
Failing that, you may just have to pretend you're on two stroke mxer, and keep the thing running by flicking the throttle....

 

[krazed0451]

Hey Thump,

I just received a 26mm OKO. Came fitted with K112/45 jets so I'll be getting a jet kit from DHZ soon... I noticed in the RevMX thread you mention they can come with either a K44 or JJH style needle. What's the difference and how do I tell them apart?

Straight top on it too, so I'll see if I get throttle stick when I get around to fitting it to the bike (just about to head interstate for a few weeks). I suspect it's gonna be a pain to fit too as I have a Nitrous 150 (which is slowly being de-Nitrous'd for motard use ) and space isn't exactly at a premium.

Cheers!

 

[sean01]

Hey Thump,

I just received a 26mm OKO. Came fitted with K112/45 jets so I'll be getting a jet kit from DHZ soon... I noticed in the RevMX thread you mention they can come with either a K44 or JJH style needle. What's the difference and how do I tell them apart?

Straight top on it too, so I'll see if I get throttle stick when I get around to fitting it to the bike (just about to head interstate for a few weeks). I suspect it's gonna be a pain to fit too as I have a Nitrous 150 (which is slowly being de-Nitrous'd for motard use ) and space isn't exactly at a premium.

Cheers!

where did you get your 26oko from?

this is mainly the reason everyone buys from DHZ as he's done the homework and hard yards with the chinamen to make sure its usable straight out the box..

as for needles youd have to do some homework yourself and compare the needles.
150 nitrous would require 36 pilot and 98 main, needle height is all up to you to dial in

 

[krazed0451]

where did you get your 26oko from?

this is mainly the reason everyone buys from DHZ as he's done the homework and hard yards with the chinamen to make sure its usable straight out the box..

as for needles youd have to do some homework yourself and compare the needles.
150 nitrous would require 36 pilot and 98 main, needle height is all up to you to dial in

China... Had a chance to lump an order in with someone else who was importing a heap of stuff, even though I'll now have to order jets it's going to have been considerably cheaper with all the other kit.

I've had a look around and can't find any information on the difference between the needle types (advantages/disadvantages etc). I'm aware of the jetting I'll need to run, I've read this thread front to back a few times now. I've also read the carby tuning thread and have a few guys who'll be able to give me a hand dialing it in nicely...

I presume Thump is requesting a certain needle type for a reason, I was just wondering what it was

Cheers!

 

[Barnesd09]

Hey krazed, remember I have a spare 36/100 for the 26mm, your welcome to give them a go, I'm running them for my 160 and they seem to be ok so far. So save the money and use these as a starting point and go from there.