Scooterotica

friend of a friend has a lambretta ts1 225, been stood over 10 years, done a full engine rebuild, bearings seals etc, fitted a new oko 30mm carb its got a 45 idle and a 140 main, needle is 3 from the top, got it to start, but it wont tick over and when you try to rev it it just backfires, any idea if the jetting is anywhere near where it should be ?
cheers
holty

What's the needle and pilot?

If it's a genuine OKO with hex jets (not a cheapo ebay copy with round jets and unmarked needle etc) then 42-45 idle,1-2 turns on idle mixture screw, 140-145 main and a JJH mid clip should get you somewhere near as a good starting point

Take the main jet out and start jetting from there can give you a clearer idea ...obviously below 3/4 throttle.
The jetting Padge mentions seems about right

I had an OKO on a piston port 225 I tuned and to be honest I wouldn't waste your time. Mine ran great and was quite easy to get to a good level. I loved its ease of set up etc. but after only 2 years of minimal use the slide was so worn the thing wouldn't even start or tick over. I had a breathe sweet filter on as well. The chrome plating was just tin foil wrapping I think! I bet it didn't do 1500 miles all told.

You might as well get a decent carb from the kick off.

A genuine OKO is made under licence (from Keihin) in Taiwan and are a decent carb, a lot smaller than a round slide, easy to dial in, smoother running and better throttle response than a round slide dellorto (ride the same bike with both carbs set up correctly and the difference is night and day) BUT The problem with these carbs is there are so many cheap Chinese copies and it's a bit of a lottery getting an original one, some of the ones I have seen are shocking, crap/sticking slides, no markings on jets/needle, bad castings/warped bodies, needle jets that wont seal etc
I've fitted and set up quite a few of these carbs an if you get a good original one and they're a great carb, get a crap one and yer pi$$ing in the wind from the get-go

Agree , I've got a stage 6 PWK and have a few OKO and badged Keihin ( but aren`t ) carbs.
Some I wouldn't use.

I nearly got a genuine PWK but in the end decided to jump to PHBH as all my other motors had them on and I had tons of spares.

The PWK is a great carburettor virtually all 2 stroke dirt bikes use them and they are very easy to set up, but my experience with the copy was initially great but ultimately poor.

I had a bgm/pwk on my iron 200.performance was great but it still had issues,had to drill out float needle jet and I'm sure there is another tube/chamber inside that needs enlarging for increased fuel flow rate to be safe. Also had Mikuni on it and now a vhst dellorto but I still say one of the most reliable out the box carbs is the phbh dellorto.

thanks for all the input, found why it wouldnt run, faulty ignition switch, replaced and runs fine now, cheers