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

[eagle]

Ok, carb seems to run pretty fine now. Gave it a good clean and heaven't experienced any fuel running out since then.
Put in a 98main and a full speed plug chop showed brown colour with a tint of gray. I'll try a 100 main soon to check if this might improve performance even more.
Pilot is a 38. Highest idle speed is at about 1.5 turns out on the mixture screw so pretty perfect I guess.
Needle is in middle position with throttle response beeing pretty cristp and clean, only twisting throttle full open abruptly from idle causes the engine to bog, apart from that throttle response is pretty impressive. It revs up into the limiter pretty fast, even under load in forth gear. I really have to make that 155ZS more rev-happy since stock CDI/Valves/cam seem to really restrict its potential. But don't now how much RPM a 155ZS would be able to handle.
Gearing is 16/41 at the moment but I don't really want to change this because of keeping the impressive torque at low- to midrange.

But this carb seems to perform pretty good once set up correctly, definately worth the money!

 

[sean01]

Ok, carb seems to run pretty fine now. Gave it a good clean and heaven't experienced any fuel running out since then.
Put in a 98main and a full speed plug chop showed brown colour with a tint of gray. I'll try a 100 main soon to check if this might improve performance even more.
Pilot is a 38. Highest idle speed is at about 1.5 turns out on the mixture screw so pretty perfect I guess.
Needle is in middle position with throttle response beeing pretty cristp and clean, only twisting throttle full open abruptly from idle causes the engine to bog, apart from that throttle response is pretty impressive. It revs up into the limiter pretty fast, even under load in forth gear. I really have to make that 155ZS more rev-happy since stock CDI/Valves/cam seem to really restrict its potential. But don't now how much RPM a 155ZS would be able to handle.
Gearing is 16/41 at the moment but I don't really want to change this because of keeping the impressive torque at low- to midrange.

But this carb seems to perform pretty good once set up correctly, definately worth the money!

good work mate.. absolute max main jet you could run is 102. any more than that and they start falling over up top and it also starts to make the bottom a bit dirty.

and just so your aware, these engines/cdi's dont have a rev limiter. thats actually valve float (bouncing) you are experiencing.

cheap fix for the valve float is a set of akunar springs or email Jamie from classic honda's as he may also have some..

cheaper and more of a quick fix is to add some extra valve spring shims under the springs. not as affective but still good enough to get a few more RPM's.

 

[eagle]

Thanks for the info! I hope it isn't going offtopic too much but... really? I thought normal stock CDIs would have a rev limiter so they can sell you aftermarked CDIs without them ;-P
Interesting to know... So I'll just need to find harder valve springs. Do you know which tuning cams would fit? Cams that wouldn't cause running into the danger of valves being hit by the piston...
Head type is the one with KLX style exhaust and a bigger camsprocket cover...
http://img38.imageshack.us/img38/4781/160ccm3.jpg
http://img825.imageshack.us/img825/8525/160ccm2.jpg

I don't want to do that much on the head for now since I'm saving on a TB V2 anyway... So maybe I'll just get the springs and leave the cam...

 

[sean01]

part # HDVYX1565
taken from the 3rd camshaft package at the bottom of the list from here AKUNAR MOTORCYCLE CAMSHAFTS

if i was to put a cam in id go the decomp D25 from DHZ but youll need to ask about the correct cam cover AUTO DE-COMP RACE CAM DHZ D25 Grind GPX YX 150 160cc | Mini Bikes | Pitbikes | Dirt Bike Parts & Accessories | DHZ Mini Moto

as for the cdi units, all they do is alter the spark curve

 

[eagle]

Thanks mate! Are there CDIs with connections for accelerator pump carbs that have throttle opening sensors to tune the curve? I saw OKO also does CVK replikas, might be a fun project to get one of these running properly...

 

[sean01]

nah mate, most the cdi's are all the same

 

[tas]

so i just put on my new oko carbie and i started it for the first time and it revs like a mofo, i know its meant to rev a lot more but im not sure if its meant to rev this much?? so here is a video of my phone to give you guys a rough idea...sorry for the crappy video..

Just click on it

 

[Neon1990]

hey guys does anyone know if a 26mm OKO will fit on a DHZ dpro160 without one of those manifold adapters

 

[sean01]

nope, it needs the adapter.. standard carby bolts on, oko carbs slide into the adapter

 

[Neon1990]

ok thanks for the quick reply

 

[JTS]

Hi Just a quick question would you use a 95 main jet for a 125 as well

 

[sean01]

Hi Just a quick question would you use a 95 main jet for a 125 as well

could try a 95 but it would wanna be a strong 125... get a bunch of jets starting from 90 to 98, try em all out and see whats better up top

 

[JTS]

Many thanks will give that a go

 

[Minibiker05]

just thought id post my jet specs:

Z160HO stock 26mm oko 102 main/38 pilot 1 1/4 tuns on the mixture screw

 

[krazed0451]

just thought id post my jet specs:

Z160HO stock 26mm oko 102 main/38 pilot 1 1/4 tuns on the mixture screw

Try posting in here too

 

[OUCH1975]

Thanks mate! Are there CDIs with connections for accelerator pump carbs that have throttle opening sensors to tune the curve? I saw OKO also does CVK replikas, might be a fun project to get one of these running properly...

you might want to check out the rextor cdi site. they have a cdi for a bike with tps (throttle positioning system) that they use for the yamaha t135 jupiter (sniper)

http://rextorcdi.com/site/?p=81

not sure thou if its applicable to mini bikes lol..

 

[lets ride]

hi i have a oko 26mm flat side on my gpx 125 and im after settings for tunning if anyone can help me

 

[Deacon fmxer]

Hey I have a yx160 with a oko 26mm im using 38 pilot and 104 main mixture screw about 1 1/4 out. needle clip on 2nd to top. ive had it on middle and second to bottom and bottom, works ok on 2nd to bottom and middle but if i slowly wind the throttle on at about 1/2 maybe little bit over it splutters abit then its fine all the way to redline. when i snap the throttle on most times its ok.
once i tryed all clips on bottom i thort id try one about middle, was smooth power all the way to redline.
it only once spluttered. is it strange that it runs best on second to top clip? isnt that leaner? im worred its running too hot, but the strange thing is it doesnt backfire and the exhuast doesnt glow.

im going to do plug chops tommorow as i only just got a new plug just then.

 

[lets ride]

i changed mine to second from the top and now its running top notch now and loving it iv learned that each bike is different so the clips will be different for everyone

 

[Deacon fmxer]

ok thanks, hopfully plug chops might tell me if its lean or not.

and when doing plug chops what do you use to clean plug after a test?