PWK 24 + Casa 185 + Clubman - rough jetting guide?

[dansuper]

Hi everyone,

I'm putting together the above spec for my LI 125 S3, and would love some feedback on a jetting start point.

Fully appreciate I'll need to spend proper time tuning by hand, eye and ear, but it'd be nice to get a head start.

Cheers,

Dan

[storkfoot]

A few questions first. Is it the ScootRS PWK? Does it have a power jet, and does it have a diaphragm attachment (just behind where the throttle cable attaches as you look at the front of the carb)? Also exactly what needles and jets do you have?

What exhaust?

I've never set up this model but I have some experience of non- power jet PWKs. Let us know what you've got

[dansuper]

Hi Storkfoot,

Thanks for the quick response.

It is a ScootRS PWK - and I've read both negative and positive things about them (including stuff on this forum).

No powerjet - but out of curiosity - can they be retro fitted? The 'hole' is there and the hose has been blanked off between the float chamber and the carb body.

Not too sure about the diaphragm attachment - I'll plead ignorant and post a pic later

I bought the kit, which includes: 108 main, JJH needle, 38 pilot.

Spares include a 5 main jet pack 110-118
Spare needle = JJF
Spare pilot jets = 32 and 34

Haven't bought the pipe yet - it will likely be an AF Clubman.

Many thanks,

Dan

[storkfoot]

OK, you can't miss the diaphragm valve, it's on the top, and it feeds down into the top of the bore. If it's there, and you don't blank it off, your carb will suck air in and screw up your jetting.

As I understand it the Casa kit is not tuned to any degree, so the jets you've got may well sort it, if they are decent quality jets. Try them but, if you start having problems, and think they may not be bored right, get proper Keihin jets and needles. ScootRS jets look a bit scabby, dull brass, poorly stamped numbers etc. Keihin ones are miles better and you know that their JJF will be leaner at 1/4 than the JJH, as it should be.

Anyway, try what you've got first before you start buying other stuff. In the absence of anyone else who'll come on here with personal experience of this carb and this kit, personally, I'd start with the 108 main, 34 pilot, JJH needle clip 2nd from top. In the UK I set my float at either 21 or 22mm, and make sure your choke is working properly. If you're going to stick up a photo on this site, I'd be interested to see the new ( I think) ScootRS choke mechanism, because the old ones weren't up to the job, at all.

If you haven't set a Mikuni or Keihin type carb before, print off the ScootRS tech pages, and the SCK catalogue, as these will be a great help to get your head round them.

Power jet. Yes, you can retro fit them but you won't need it with a Casa kit and a Clubman. Let us know how you get on, and good luck

[dansuper]

ScootRS jets look a bit scabby, dull brass, poorly stamped numbers etc.

Yep, that's a good description for the ones supplied! Interestingly the pilots and needle look very bright in comparison. I wonder what the deal is?

I haven't got a pic of the choke mechanism, but it is the 'same' as the one pictured here. I say 'same' as there are slight differences in the the size of the nut, the thread depth, the hole in the plunger etc, but it is essentially identical. Do you know if this is the new one, or the old one? What was the problem with the old one?



I've had a look at the ScootRS tech pages and will bear all the related info in mind. Off to look at the SCK info now. Will hopefully be in a position to commence the engine rebuild soon.

Also very interested in anyone's feedback on gearing for this kit. A friend is running ultra tall gearing and loves how it works with the Casa's torque. But I've read other things where people (from the UK) seem to be relatively disappointed. My intention is to run a GP200 set up, so I think that's about 5.2 final drive. I would love to be able to cruise at about 95 kph and stretch to 105kph if possible (60 - 65mph).

Cheers,

Dan

[storkfoot]

To my knowledge ScootRS never have never sold any genuine Keihin jets and needles. Genuine Keihin ones have the Keihin star shaped logo stamped next to the number. Many bikes have Keihin carbs so you shouldn't have much problem getting them if you need them.

Those pics are different to the ones they used to sell. Whether they are any better?? The throttle adjuster in the photo doesn't seem to allow it to be screwed into the top of the carb?? I use standard dell'orto adjusters which screw straight into the top of the carb.

My choke adjusters are from SCK. They are better made and, more importantly, have a stronger spring. Rather oddly though, I found the ScootRS plunger to be the correct size, and the SCK one too big

5.2/ GP200 gearing would be good for your set up but I doubt you'll see a genuine 65mph, maybe 60.

[rog60]

Not sure if this is relevant but I am running a Casa210 kit with SX150 gears 19x47 sprockets and Delly 28mm carb/KBA Clubman exhaust.(4,54 final drive)
It is much torquier than the supplied Indian Stage 4 barrel set up but doesn't rev very highly. (I can only get an indicated 65mph in 4th max). The Casa kits seem to prefer tell gearing????

I have test driven the Scootopia SX150 with Casa 185 and this copes very well with the jump from 3rd to 4th and will also pull away in 1st or 2nd (they have fitted Sx150 gears, 17x46 sprockets SH1/20 jetted to 118 main and 50 pilot and clubman exhaust.

Finally I am building an Sx150 with Casa 185 similar to Scootopia's set up............will post results when finished.