Scooterotica

Just got a new carb for the Lammy and was looking for confirmation that I'm starting in the right ballpark with the jetting (hoping not to blow it up straight away ).

The engine is a 225 Rapido classic with a bit of porting to "stage 4" specs ( 170ex/126tran/150inl), casing matched to transfers, manifolds matched, JL3, Indian GP200 gearing.

Carb is an OKO PWK 28/30 and I am thinking of starting with a 40 pilot, 132 main, JJH needle middle clip, remote foam type filter (think it might be a Breathsweat).
Most riding done pretty near sea level and in warm temps (upto about 40c).

Any suggestions/comments welcome.

I have a similar top end & carb, but Rapido Race version & no filter, but it looks about spot on to me, perhaps a tad rich with the remote filter.
Don't forget to get the float height as high as possible and grind off the small float stops inside the bottom of the bowl, otherwise starvation issues may occur when WOT.

chris2470 wrote:Don't forget to get the float height as high as possible and grind off the small float stops inside the bottom of the bowl, otherwise starvation issues may occur when WOT.

Already done , and thanks for the reply.

The pilot might be a little rich so be prepared to drop a size or 2 if it's boggy at low revs. With regard to fuel starvation, make sure you mount the carb as upright as possible (check off stand sitting on bike) as that will also affect the fuel level in the float bowl. The PWK float bowls are small compared to a PHBH and need a lot more care in positioning than a Delortto.

coaster wrote:The pilot might be a little rich so be prepared to drop a size or 2 if it's boggy at low revs. With regard to fuel starvation, make sure you mount the carb as upright as possible (check off stand sitting on bike) as that will also affect the fuel level in the float bowl. The PWK float bowls are small compared to a PHBH and need a lot more care in positioning than a Delortto.

Thanks for the info, I bought some extra jets when I got the Carb so I'll keep that in mind.

Well even with my first guess at jetting I seem to have got rid of the 4 stroking at low throttle openings that was plagueing me with the Dellorto. Early days, but so far so good.

Any update on this? Have you changed anything?

corrado wrote:Any update on this? Have you changed anything?

Hi Martin, no changes so far, but I have been in catchup mode at work after a 3 week holiday in the UK (I'd forgotten how cool a English warm summers day could be ).
I took my exhaust off for some paint while I was a way and haven't got it back on yet. I also got the LTH filter elbow that you recomended for the PWK (thanks for that) while I was in the UK and once I get this and the exhaust back on I'll do some plug chops and see where we are!
I'll report back when I find out what's what.

Hi John, you may be aware when following jetting posts and set ups on here most are used on engines in a climate with more air density than our climate so jetting will generally be richer for like engines.
Start points are great cause it means erring on the rich side. I never jetted a like engine any where as rich as i did back in England

Your right about that Mick, they've been complaining of extreme temperatures of 25C +
But as you say It's better to start off rich and then lean off.
I'm assuming that lower temp= higher air density, therefore needing bigger jetting?
I guess cos the Perth coastal plane is basically sea level at least altitude won't have any effect. I wonder how high you have to go before there is a noticable effect?