Scooterotica

Have you tried

52 idle
AV266 atomiser
X13 needle
118/120 main

That should be somewhere near if you haven't got an air leak or a problem with the choke plunger (very common) You need plenty of play in the cable and to ensure that the spring is pushing the plunger home.

what problems are you actually having?

Talking about 5000 rpm & Needles.
I was going to post my findings & pick your brains.
But there's a post going.


I fitted an EGT & Rev counter before setting off for Spain.
RB22 35mm Mikuni with filter, full panelled
320 main
22.5 pilot
57 needle 2nd clip.
18deg
AF close ratio gearbox & 19 x 46
Franspeed tourer.

My main concern was travelling at the 5000rpm mark
cased of constantly speeding up & slowing down & bringing the main jet on line.
This I found strange as the Scoot just ticks over fine & before fitting the EGT this is where I would sit as I plodded along.

The scoot will not rev much past 7000rpm & the EGT reads 475-500 at 6000+rpm
At 5000rpm it can get up to 650+C.
I can keep it below 600C.

What will at franspeed tourer rev out at & what's the ratio of this gear box.
I don't think my speedo is too far out for a Lambretta at 6000rpm it says I'm doing 70mph.
Flat out is off the clock & shockingly fast on 10' wheels.

Do you think dropping down to the 3rd clip on the needle will help any?

drunkmunkey6969 wrote:what problems are you actually having?

I have a dual EGT/CHT gauge installed as well as a rev counter (tachometer). My exhaust gas temps spike to 1200F in the 25%-50% throttle range, indicating it is leaning out.

The only atomizers I have tried are the 264 and 266 with the X4 and X7 needles.

Can these PHBH carbs be dialed in reliably or should I dump it for something else? I don't want to continually fight this thing.

DaveInPortland wrote: I have a dual EGT/CHT gauge installed as well as a rev counter (tachometer). My exhaust gas temps spike to 1200F in the 25%-50% throttle range, indicating it is leaning out.

What pilot jet and what slide are you running?

RBG.....crikey.....one question at a time please mate!

So.....to clarify:

1) Your RB doesnt rev over 7000rpm?
2) At 5000rpm the heat spikes from 475 upto 650+ (what part of throttle are you on here?)
3) You want to know what a franspeed tourer will rev out to
4) What is the final drive ratio of and AF close ratio gearbox on 19/46
5) Will dropping down to the 3rd clip on the needle will help?

Am i correct on what you are saying and what you want to know?

just generalizing here of course..........
but if your EGT,CHT guages are telling you that your motor is overheating at a certain rev range....................
it does not always equate to the fact that it may be a carb prob and too lean..................
consider also that its just not cooling efficiently enough at those typically 4th gear low speeds.............
the choice of gearing can effect cooling..............

drunkmunkey6969 wrote:RBG.....crikey.....one question at a time please mate!

So.....to clarify:

1) Your RB doesnt rev over 7000rpm?
2) At 5000rpm the heat spikes from 475 upto 650+ (what part of throttle are you on here?)
3) You want to know what a franspeed tourer will rev out to
4) What is the final drive ratio of and AF close ratio gearbox on 19/46
5) Will dropping down to the 3rd clip on the needle will help?

Am i correct on what you are saying and what you want to know?

Yes mate.
1. yep 7K is about the lot. "I have a feeling that it could be the CDI" but not knowing the limit of the exhaust.
2. 1/3-1/2 throttle. Bliping the throttle brings the temp down.
3,
4. 4.8???
5. please
Other than the 5000rpm temp shocker she's running well.

Thanks.

RBG wrote: Yes mate.
1. yep 7K is about the lot. "I have a feeling that it could be the CDI" but not knowing the limit of the exhaust.

My Franspped Tourer would rev to 8000rpm according to my Pitsch Krober rev counter.

I split my inquiry off to it's own topic. We have a few different conversations going on here and it's going to get confusing.
http://scooterotica.org/forum/viewtopic.php?f=7&t=2928