Jump to content

neo

The Oko 24 Rock Test

Recommended Posts

Wow....you got a good result without even touching or knowing he setup....That's AMAZING!! :D

Best of balance.

Neo

Share this post


Link to post
Share on other sites
 

Well, that is good to hear from bob as well!!!! Goes to reaffirm a few things i have tried to point out here based upon my experience, mainly the fact there is littlle varience upon application.

The experiment with the 4T seems to reinforce that point, yet I still think it could be improved upon using the SPS mods, or sleving down an SPS carb possibly.

In my experience, the CV carb as used on the Beta is tyhe best yet on a 4T! It will chug LOW, still respond when a Mont flames out! I say that, having ridden the Betas briefly in both 250 ang 300 configs, but I do have both a Suzy 250 quad and a Yam 225 Serow sitting here with basically the same setup. They work well if one has room to fit them on the bike! Not happening on a Sherco!

Minimizing spitback on the 4T is key, and I had predicted that the 24 may work well, much here is a tradeoff for top performance, yet once again, I know few folks that can ride a 3.2 at WOT as well, and need that much power. Same as the 2.9, most folk just cannot handle the power! The Quickness! And better progression is just better!

I still have reservations about the fitment of the carbs on the Sherco, very tight fit with the bowl hitting the cases! I do have something of an idea of using the 5mm spacer plate off the '05 2.9 and putting a bit of bevel on it, putting it on the carb side of the reed block, then a bit of angled spotfacing on the carb adapter to accept the angular difference, not too much, maybe 5% or so might help. OR even doubling them up? To obtain that 10mm difference that Marlintec pointed out?

I do have a nice recommendation for an inlet rubber that seems to work well, off an aircraft, reinforced inlet hose. The friggin thin is still stuck tight to my K carb (without a clamp) from 4-5 years ago!

MC

Share this post


Link to post
Share on other sites
 

hey

some more info on my 24 mm carb

my jets are 37 pilot 105 main and powerjet connected

the guy who sold my the carb told me: use 35 pilot 98 main without powerjet (take it out and put a screw in that hole) i wil try it as soon as possible but it should be ok he owns a 4 stroke too and he is a very good engenier and developer of trials bikes.

regards bob

Share this post


Link to post
Share on other sites
 
hey

some more info on my 24 mm carb

my jets are 37 pilot 105 main and powerjet connected

the guy who sold my the carb told me: use 35 pilot 98 main without powerjet (take it out and put a screw in that hole) i wil try it as soon as possible but it should be ok he owns a 4 stroke too and he is a very good engenier and developer of trials bikes.

regards bob

Would that be from Classictrial/ fellow?

I found one on ebay, god only knows whats in it, but I do have the K here to swap jets and such if needed.

Finding jets locally is a real pain in the butt!

Edited by copemech

Share this post


Link to post
Share on other sites
 

Look a bit more on ebay & you'll find 20 piece kits for not much. From what I understand pretty much everything is interchangable between the 2 brands

Share this post


Link to post
Share on other sites
 

hey

its not the classic trial guy but he knows his stuff well too, normally he can help you also.

i bought it from Jon Bliss (he does the flywheel conversion on the 4 strokes and the 24 mm carb

(that setup seems to be a lot beter dan stock in the slippery parts of the uk)

Share this post


Link to post
Share on other sites
 
Any idea what jetting and needle is in the Xispa's?

Do they look like these with the balance tube connected form inlet to bowl? No lower tube on the bowl?

the tube dends feul to the "power jet" a very small 3th jet on top of the carb inlet

it gives more fuel on higher revs (for thumpstars and so) for trials it is not needed just take the 3th jet out and close that hole

regards bob

Share this post


Link to post
Share on other sites
 
Would that be from Classictrial/ fellow?

I found one on ebay, god only knows whats in it, but I do have the K here to swap jets and such if needed.

Finding jets locally is a real pain in the butt!

those on ebay mostly have jets for dirtbikes like thumpstar and so (42 pilot and 107 main or even bigger)

that jetting worked fine on my sherco also but mixture screw 4-5 turns out so way to ritch

Share this post


Link to post
Share on other sites
 
From what I understand pretty much everything is interchangeable between the 2 brands

Everything but the slide.....the OKO slide will not go inside a Keihin....it's just a fraction bigger and jams half way down....The Keihin slide has a much better chrome plate on it too.

That power jet and tube has been on our 24mm/125 for a year or so....I've seen no I'll effects so I'd leave it as it is for now.....I still wonder why and how the 24mm carb spits/spills no fuel....is a very clean carb.

Another thing I've noticed is the standard OKO metal bowl is a couple of mm deeper than the OKO clear plastic bowl or the Keihin metal bowl. So in theory it will rub harder against the gearbox case on the 290/250....So I'd recommend that people buy the plastic bowl.....It's good fun watching the floats go up and down while your riding too :D

I've just got hold of an OKO 26mm....It comes with a 100 Main, 36 Pilot and JJH needle...so not that far out.....but it does not come with the power jet and tube....so I'm interested to see how clean it keeps compared to the 24mm.

I feel the "The OKO 26 Rock Test" coming on this weekend too :D

Best of balance

Neo

Edited by Neo

Share this post


Link to post
Share on other sites
 

I got the 24 today, looks like it needs some massaging but i am out of town for the weekend on the French Riveria(Oklahoma Lake) :D

Came with a 45/111, JJH setup? Should work, as with the boyesens i have had to run a leaner main jet at 110 to get total cleanout and rediculous revs that are totally unusable! Went back to the 115 on the Dellorto just to add a rev limiter so it never really cleans out and goes to 13000!!!! \

With the smaller carb, I may advance the timing a bit to find the balance in this power curve on the 2.9? Still quick with a bit less HIT is where the 250 exceeds! And at the same time the 2.9 can be torquey but more of a handfull in the revs.

My private jet is waiting! Gotta go! (Honey, can you fire up the diesel, I have had a few!) :D

Edited by copemech

Share this post


Link to post
Share on other sites
 

hey

had a trial yesterday with the 24mm oko, first 2 laps i rode very bad on the sections where you needed power in 3th gear (very loose climbs ),

last 2 laps just went verry good (from 19 points a lap to 2 point)

i hadn't trained on the bike yet and i guess first 2 laps i needed some time to addapt to the bike.

but now i'm verry happy with my bike it still flies up loose hills where most 2 strokes just don't get (4 gear full power :) ) and is more smooth in low revs

regards bob

Share this post


Link to post
Share on other sites
 
 

The previous importer here put 1 on a early model 3.2 & couldn't speak highly enough of the carb, think it was the stock size though- 28mm?

Maybe these are the go on shercos

Share this post


Link to post
Share on other sites
 
The previous importer here put 1 on a early model 3.2 & couldn't speak highly enough of the carb, think it was the stock size though- 28mm?

Maybe these are the go on shercos

that 28mm oko is how they are sold now (well its a keihin but its neerly the same carb),

i really think the 24mm is a great improvement for most riders ( top guys may miss some high end power?)

now i will "develop" my bike further i plan to change ignition timing by slotting the mounting holes a bit so i can turn the ignition plate a bit and mayby put a trp rear shock on the bike

i would like to increase the weight of the flywheel a bit to but that seems not so easy.

regards bob

Share this post


Link to post
Share on other sites
 

The early ones were a lot more docile than the later models, great for clubmen etc, from trying a new one out just after it had been assembled I think they're aimed more at the top guys now as the power is quite aggressive

Share this post


Link to post
Share on other sites
 

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...

×
×
  • Create New...