PHBH 28

[Meds]

I am trying to set up a rapido 225 race, MB clubman, BGM electronic approx 17 deg
Phbh 28, pilot 50, 40 slide, main 120, needle x7 second from top. AV 266 mixture screw approx 1 turn out, open bell mouth.

The scoot start and ticks over when I try to pull away it bogs down so I have to rev it a lot.
Using MB site I diagnosed this as weak mixture and upped the pilot.
I replaced to pilot with a 55 which has improved it but it still needs a lot of throttle.
I have tried leaving the choke on when pulling away but it runs worse so not sure my initial diagnosis was correct.

My next thought was timing but as it starts ok I dont want start mucking about with too many things at once?

Help gratefully recieved.

[MickYork]

"Bogginess" is usually a too rich mixture not lean. BY upping your jet you have made it richer which should have a worse effect, not better ?

I would check that your choke is shutting of fully as this may be a cause.

The 120 main jet is probably about right but I would go to 125 and come down if needed (120 may be a touch too lean).

17 degrees is about right but if you're out by a couple of degrees and it's 15 that could account for the "bogginess"


good luck

[skinnerwill]

I was going to say re-check the information you read, I thought bogging down was too rich.

[Meds]

Cheers for the advice but unfortunately when I try and pull away it dies off then picks up.
I have tried increasing the timing by 2 degrees,my hats improved the starting.
I have tried a 45 and a 55 pilot jet, confirmed the path up to the carb is clear
I have checked that the choke is off
It's still doing the same, when I get it moving its ok
The atomiser is a 266
My next thought is an air leak somewhere?
Any ideas

[MickYork]

could be electrical.....faulty stator, cdi, spark plug, HT lead, flywheel ?

Something else to think about

[camel]

Try an av264 atomizer with an x13 needle....that combo you have is usually the set up for 30mm carbs.I'd be tempted to run a 125 main too...initially at least

[ian i.o.w]

I run rapido 225 I have a 30 mm dellorto similar set up but use a AS266 atomiser with marchard air filter runs lovely

[Meds]

Thanks for all the help.
I can't identify the exact problem but it's running and pulling away now, the set up isn't perfect but it's close and needs further tweaking.
I went back, re-made all the electrical connections, changed the new plug of an old known good one.
45 pilot, 2nd clip from the top on an x7 needle, mixture screw 1.5 turns out.
Removed the choke cable and fitted a simple length of cable to ensure that it is always off.
I will get it set up then sort out the choke cable, then the plug
Thanks guys

[corrado]

With regards to the choke I always recommend sticking with the factory "flip-up" choke until you've got it up and running and got a few miles under your belt. Taking the side panel on and off is not such a bit deal in the scheme of things.