Avanti set up

[dapper]

Avanti 225cc
JL3 exhaust
28/30mm OKO carb
Li150 gearbox
Anyone running same set up? Looking for jetting tips. I did contact Ron Moss, who advised that someone local to him (think he said the guy was called Max) was running a KOSO carb.

Here's his reply:

Jetting for Koso 30mm carb:
Main Jet 140
Pilot 50 - 52
JH needle top notch
air screw 1.5 turns out

hope this helps
regards
Ron

I tried this set up, and the scoot seemed very boggy when pulling away, to the point I had to pull the clutch in and twist the throttle a few times to get the revs up required to pull away. I've tried a 50 pilot and it still seems the same. PWK carb has had all the mods done to it.
Now I've met Ron on a few occasions and he's a really nice guy, but this pilot seems very large to me. I've looked on the ScootRS PWKcarb jetting guide and whilst there are a few using pilots around the 50 mark, most seem to a bit lower than this, so looking far a bit of guidance, please?

[corrado]

I'd try a smaller pilot jet.

[goldeneye]

I run a KOSO on a tuned 200 cast barrel and modified indian big bore pipe, JJK needle 2 notch from top, 38 pilot, 125 main , mixture 1-1/2 turns out, runs great. use BGM jets and needle if you can, the Vietnam versions of the jets you get with an OKO are all over the place.

[coaster]

I agree, the pilot seems way too big, I'd try something around 40 TBH, I would think that with a 50 in you would struggle to get the idle screw to make any effect

[shocky]

I ran a 38 on my oko was ts1225

[SpanishSX200]

38 pilot on my RT 230. 108 main thru an airfilter. JJK needle from memory. Ran great for about a year and then everything fell apart at the same time. Plating of the slide, jets with pieces falling off, needle worn to not a lot. If I was to buy another one it would be a keihin original. But they are easy to set up

Simon

[dapper]

Thanks guys. Thought it was a bit too big. I am using proper Keihin PWK jets from Splat shop and am awaiting delivery of 45 and 48 pilot. I have smaller ones, a selection of needles and main jets too. Maybe it was just a typo by Ron.

[Adam_Winstone]

I wonder if Ron's was one of those that had not had the body drilled to allow a decent amount of fuel in? It might be that his figure was big as he had no idea that the carb body was the limiting factor.

This does sound a little like when people go bigger and bigger on Dellorto VHSA/VHSB/VSHS pilots, unaware that they might have a sized pilot emulsifier tube under their pilot jet. Unlike the generic CD1 emulsifier tubes, some of the tubes are sized and can be used without another pilot jet in the system.

Who knows?!

Adam

[coaster]

One other thing to bare in mind with the 28/30mm PWK type carbs is that the float bowl is a bit on the small size and you run the risk of sucking it dry at full throttle. Careful setting up of the float height is essential as would be making sure that it sits upright when you are riding it, this is even more important with kits which are a bit on the thirsty side. I had an OKO 28/30 PWK on a home built read valved SR225 barrel which melted 3 pistons and I'm pretty sure the fuel level was to blame (it did have a LOT of down draft angle on it though). Currently have a BGM 30mm PWK on a TS1 which is running very sweetly though

[OAP]

Just to clarify this: I did NOT set that carb up, A.N. Other did, the sizes given were exactly as given to me. Also I have never test ridden that machine so I cannot say how it was running. It was an assumption on my part that the customer was happy the way they had set it up! Having said that the customer has now dumped that carb and is now using a Dellorto.

By what has been posted it is obvious that the pilot jet is far too big, anyone with one of my kits & has running issues can always call me,
it's FREE although sometimes I wish I had an 0900 number. Or you can arrange to call in and I will stack your bike on a test run.