30mm OKO Carb

[kevspeed]

Anybody on here running a 30mm OKO carb on their Lambretta?,if so,any hints/tips?,ive not used one before,but have been offered one to try out!!

[dapper]

Running a 28/30mm on my Avanti. If you don't know much about them, there are certain mods which are required to be carried out.
1. Don't use a clear plastic float bowl. The petrol/ethanol warps the plastic. Use a proper ally bowl.
2. Grind out the float stops in the bottom of the bowl with a Dremel to help prevent fuel starvation.
3. Use proper Keihin jets and needles from Splat Shop.
4. Because I'm a lazy fecker I can't be arsed to type up all the other bits you need to do/check, so do a search on here and all the detail is there.

They have come in for some stick off some scooterists, but I think a lot of the problems people had when they first tried them out were down to not knowing about or doing the mods required. They are very simple to set up compared to a Dellorto.
If you want to know more PM me.

http://www.miniriders.com.au/tech-talk/ ... -mods.html
http://www.carbparts.com/keihin/needles ... r_carb.htm
http://scootrs.com/tech.cfm?tip=jetpwk
http://www.splatshop.co.uk/performance- ... pares.html

[kevspeed]

Thanks for the quick response,very useful links,ill give it a go later in the week,if all is good,i may well invest in another!!

[ArmandTanzarian]

The float stop thing is important. If you don't do it, they suffer from fuel starvation.

Check the choke is moving freely too. Mine wasn't sitting all the way down and so when I set it up the choke was slightly on. A few miles worth of vibration and it closed properly making the engine run lean. This was shortly followed by a loud bang and a holed piston.

[Minority]

I use one on my Rapido 225 and prefer it to 30 PHBH that was on there before.
Biggest difference that I noticed was the cleaner running at low throttle openings.

[dapper]

Also try to set the float height as high as possible by bending the little tab, as this also helps prevent fuel starvation. Oh bugger, I might as well of typed the whole thing up

[goldeneye]

mines a 28/30 mm oval bore flatslide KOSO, like a better quality version of the OKO, but not as good as the Keihin they are based on. I cant really fault it, it gives more power , and 15 mile more to the tank than the 30mm dellorto I had on, was easy to jet , and very cheap to buy, and came with 2 boxes of BGM jets /manifold, 2 rubbers and 2 clips , five needles and a foam filter ...50 quid! I ground the float stop off , but didn't really do much else. settled on a jjk ,top notch needle, 36 pilot and 125 main jet on a cast 200 with clubman style exhaust. goes well. I could get away with a leaner pilot jet (32), but keep the richer in for when i want to cruise at low throttle opening. good carbs when set up right.

[hobospeed]

Check out this great site when it comes time to fine tune your carb's jetting/needle set up:

http://www.kyajet.com

I love that you can have your current jetting plotted onto a graph and then overlay changes.

Tim

[shocky]

Check out this great site when it comes time to fine tune your carb's jetting/needle set up:

http://www.kyajet.com

I love that you can have your current jetting plotted onto a graph and then overlay changes.

Tim

Great info

[LI225Canada]

I am using a 26mm OKO. Even though I had done all the recommended modifications I still could not get it jetted. Pulled it apart 'again' and found that the main fuel port right above the float needle valve was drilled off-centre so was starving for fuel. Corrected this and was able to get it jetted (Basically you have to re-drill everything.) still not 100% there yet with the jetting.
Other irritating issue[s] is the top cable guide does not fit a standard cable end and it comes loose and falls into the carb body. Corrected this issue with a dab of solder.
In the end I got it working but it was a hassle, maybe get a BGM unit or save up for the Keihin.
FYI, It is running a Rapido 225 Classic w. a Ancillotti, Uni/Ram air filter. Pulls-like-stink.