OKO carb on early MAR

[Ftwelder]

My original IRZ is working just fine and with very low miles I decided to try replace it before wearing it out further.  I purchased a Taiwan made OKO kit from Mid-Atlantic trials (I am in the states) and wonder if any of you had gone this route? The tuning seems straight-forward. 

[feetupfun]

Yes they have been a good thing on every old two stroke trial-type motor I've put one on so far

[cleanorbust]

I agree with feetupfun. Put one on my SWM and it pulls much better from the bottom of the range and runs cleanly throughout. Mid Atlantic are a good company to deal with and have worked hard to get the OKOs properly dialled in for specific models.

[bullylover]

I have one on all of my 3 Sherpa Ts and they all work very well. Easy to get right and the D slide ones have much better pull right off the bottom.

[teamferret]

Is there anywhere in the UK to get OKO's from?

[cleanorbust]

I looked into that and the answer is no. The previous importer no longer does them. You can find cheap Chinese copies on eBay, marketed as OKOs, but they're not worth having by all accounts. I dealt with Mid Atlantic Trials in USA and found them excellent. Cost was about 118 quid delivered and set up ready for my bike, with some extra jets and hose to attach to air box. I think that compares quite well with buying a new Amal or Mikuni in the UK.

If you take a look at Mid Atlantic's website you'll be able to read about what they do with OKOs.

[Ftwelder]

It seems I only need to shorten the throttle cable housing 17mm and it should bolt right on!

[woody]

1 hour ago, teamferret said:

Is there anywhere in the UK to get OKO's from?

Nowhere, only copies

Buy direct from here

https://www.ebay.co.uk/itm/OKO-26mm-RACING-CARB-FLAT-SLIDE-CARBURETTOR/302886110025?hash=item46856b4349:g:rRQAAMXQHO9Re1yr

 

[cleanorbust]

5 hours ago, woody said:

Nowhere, only copies

Buy direct from here

https://www.ebay.co.uk/itm/OKO-26mm-RACING-CARB-FLAT-SLIDE-CARBURETTOR/302886110025?hash=item46856b4349:g:rRQAAMXQHO9Re1yr

 

I didn't know about that source, have you tried it yourself? Would be interested to hear your experience if so. Half the price of the ones from Mid Atlantic  but are they the same, ie genuine OKO? Also a question of how they're jetted I suppose. 

[woody]

Genuine OKO yes, I've been buying off them for about 10 years.  For virtually every bike I've put them on they run virtually straight from the box with minimal change, usually drop the needle one notch and maybe down one size on the pilot jet. Jets are standard Keihin. They come with 112 main and 48 pilot. I've never had to change the main jet.

Out of interest I bought one from Mid Atlantic a couple of years ago jetted for a 310 MAR, I wanted to see what differences there were in jetting from how I had mine jetted. It came with a weaker needle but bigger pilot jet. The bike ran the same with either carb

[Ftwelder]

1 hour ago, woody said:

Genuine OKO yes, I've been buying off them for about 10 years.  For virtually every bike I've put them on they run virtually straight from the box with minimal change, usually drop the needle one notch and maybe down one size on the pilot jet. Jets are standard Keihin. They come with 112 main and 48 pilot. I've never had to change the main jet.

Out of interest I bought one from Mid Atlantic a couple of years ago jetted for a 310 MAR, I wanted to see what differences there were in jetting from how I had mine jetted. It came with a weaker needle but bigger pilot jet. The bike ran the same with either carb

Months ago I bought a random 26mm OKO off ebay to use as a mock-up for my BSA and it ended up being legit. My new one should arrive tomorrow so Ill compare the internals myself.

[cleanorbust]

2 hours ago, woody said:

Genuine OKO yes, I've been buying off them for about 10 years.  For virtually every bike I've put them on they run virtually straight from the box with minimal change, usually drop the needle one notch and maybe down one size on the pilot jet. Jets are standard Keihin. They come with 112 main and 48 pilot. I've never had to change the main jet.

Out of interest I bought one from Mid Atlantic a couple of years ago jetted for a 310 MAR, I wanted to see what differences there were in jetting from how I had mine jetted. It came with a weaker needle but bigger pilot jet. The bike ran the same with either carb

Thanks, appreciate the reply. Thinking of trying one on my Cota 247 - nothing wrong with the standard Amal but I was so impressed by putting an OKO on the SWM that for 60 odd quid it's worth a try.

 

 

[Ftwelder]

I finished installation and it started first kick. I tried using the stock rubber spacer with the adapter spigot supplied and had a big air leak once the bike warmed up. I righted that and adjusted the idle circuit. It's very close to perfect. Ill raise the needle a little tomorrow and see if the acceleration can be improved.  I like it so far.