Scooterotica

hello all,

I have a Rapido classic 225, Nk Rally Road and 30mm PHBH. I want some advice on the jetting now as it has been slightly tuned and manifolds have been matched. The exhaust port is now aprox 67% of the bore.

Current jetting which has given a nice brown plug;

Main - 125
Pilot - 60
Needle - X13
Clip Position - 2nd from top

Cheers,

Is the atomiser an AV266 or AV264? Is the carb filtered? If so, how?

I'm not especially familiar with the Rapido, although as you say it's been tuned, unless you're able to specify the port timings it would be difficult for any of the guys on the forum to give you reasonably precise jetting feedback.

From my knowledge of the PHBH 30, the 60 pilot seems a bit big but if you have the leaner atomiser, the AV264, that may be an explanation.

PSL in Kirkby charge £45 (that was last year) to dyno it. That includes an air/ fuel analysis. You can save yourself a small fortune on jets and needles, and petrol, by dynoing to set the carb. I think you're in Cumbria so how about booking it in on the way to one of the first "southern" rallies of the year

Other dynos are available and I'm not on commission

Thanks for the advice... I forgot about the atomiser which is the AV264. And it is not filtered.

Basically the exhaust port has been raised and enlarged, I don't know the exact port timings. He did say that he would expect it to rev on for approximately 500rpm more. He hasn't modified the transfer or inlet port timings, but has slightly reshaped them. And all the manifolds have been matched.

I was just hoping for a guide for some safe jetting as I will get it on the dyno, I just need to find a spare weekend and where to go. I never thought of doing it on the way to a rally, I plan on doing Modra.

rayspeed used to publish a ball park jet settings on their site,its gone now but here is their recommendation for a rapido race 225 with an expansion pipe and 30mm round slide delorto carb-main jet128,slide 30-40 deg,av 266 attomise/needle jet,x7 needle 2nd clip from top,55 pilot,70 choke and mixture screw 2.5-3.5 turns out.hope this helps cheers Jeff.

I have exactly same setup as you currently except barlow has reworked transfers

I have av266 x7 p2.5 pilot 55 and a 118 main, air 1.75 all dynoed and all sweet, but thats my motor not yours.

I have been for a few runs out..,. Including some fast dual carriage way riding with the current jetting set up. All seems well so far, but will check plug colour tomorrow when i get chance.

Here is a pic of the plug... I havent done a proper plug chop yet, but the last bit of riding was fast dual carriage way at full throttle for a few mile or so. It looked a tad lighter in reality. I have upped the main jet to a 128 and will see how i get on, but it doesnt look too far out.

Lookin good on the plug.

Havn't had the privelege of that exhaust yet (how is it?) Jet numbers look good to me and prob to reduce size on the pilot/idle to mid 50's eventually

"but the last bit of riding was fast dual carriage way at full throttle for a few mile or so". Still running in then!. If you feel it starting to slow then flick the choke on whilst NOT shutting the throttle off. Could be a Guiness Book Of Records fastest run-in tiime? You'll have to ask http://www.norrismcwhirter.com/ to be sure!

I am now running a rapido race 230 and having trouble getting it right.

On the coast to coast i ran;

60 Pilot
AV264
X13 3rd Clip
140 Main
40 Slide

It was OK, but quite boggy especially when going up hills from low revs.

I upped the clip position to get up the passes, but the plug went a much lighter colour.

I have tried an AV266 and X7 2nd clip down, boggy and wont pull. AV268 and X13 2nd clip down, just as boggy again.

At the moment I have,

60 Pilot
AV264
X7 2nd Clip
135 Main
40 Slide

This is OK, but stutters at low revs and struggles up hill from low revs. If you gently wind up the throttle it is OK, but if you open it up really quick this is when it bogs. It also stutters a little on 3/4 throttle.

Any advice appreciated.