My bike - carb issues part 2, fixed

Following on from part 1 of my carb/ running issues I have now re-built the carb to exact Aprilia specifications. For good measure I replaced the spark plug which is a NGK BR10EG and I also had to replace the battery as mine was dead and wouldn't except a charge, I bought a Motobatt 12N5.5-3B from Busters.

With everything back together the bike fired in to life, ran sweetly and most importantly the carb didn't over flow which points to the float weight all along.

Now that I am happy that bike is running correctly I can move on to some more restoration type jobs.

Carb settings - 1989 Dell-Orto PHBH 28 RD

 Carb settings - 1989 Dell-Orto PHBH 28 RD

Here are the stock setting parts and sizes for the PHBH 28 RD as fitted to the1989 Sintesi Replica taken from the 1989 owners manual. I have added links to the UK Dell'Orto supplier, just select he variant size you need.

Main jet – 120 - order here
Idle jet – 55 - order here
Atomiser - CF 266 - order here
Needle - X4 third notch from the top - order here
Slide - 50 - order here
Air screw – 1 turn
Choke jet - 70 - order here
Float – 11.3g - order here

The idle speed adjustment must be carried out with the engine warm, proceeding as follows.

- Adjust the idle screw (fig. 17 pos. A) in order to obtain a constant rotation of the engine.

- Tighten and unscrew the air screw (fig. 17 pos. B) until the highest number of engine rpm is obtained

- If necessary, further adjust the minimum screw

Note if you buy a brand new complete carb it will need setting to the above specs as it will not be set up for the AF1, plus you will need the cable choke kit rather than the manual lever. Buy a complete carb here