Topic: PD42 carb #2 fuel lines

[Frank Rodgers]

I'm putting together a 77F 750 much of which came in boxes.  I'm using PD42 carbs and it is not obvious to me as to the setup of the fuel supply lines to #2 carb. On number #2 carb on the left side of the carb are 2 spigots. The larger one is the fuel supply from the gas tap I assume but what is the smaller diameter spigot in front of the larger spigot for and where is it connected?

[madmtnmotors]

The smaller one is the bowl vent that is shared between the four carbs. The bowl vent crossover tubes is the small rubber line connecting the carbs just below this connector. The stock configuration uses a small rubber line connected to this vent and routed up over the airbox. There is a small clip on top of the airbox to hold this vent line in place, open ended, facing to the rear.

[Frank Rodgers]

Thank you. That is very helpful information.

[madmtnmotors]

Happy to help. There is a very informative thread dedicated to these PD carbs as well:

http://forums.sohc4.net/index.php/topic,48858.msg515204.html#msg515204

[Frank Rodgers]

I searched the forum and have read the thread you reference but it didn’t  answer my specific question but is a very valuable  guide to rebuilding  PD carbs.
In the late 70’s I had a 71’ 750 and then a 74’ Rickman CR but afterwards a steady diet of 750/850 Norton’s and 650/750 Triumph’s and then BMW K bikes. Stopped riding in 2012 to design and build our own home on the West coast of Canada promising myself I wouldn’t buy a bike until the house was finished which has taken 7 years. I did buy a Ducati Monster but traded it for work on the house! Definitely a character weakness on my part. I used to buy and sell British bikes and would come home from a swap meet and tell my wife that a bought a bike or 2 today and she would say, “ that is not news, tell when you sell one.” With 5 children The bike sales financed college education and daughter’s marriages hence the Rickman sale.
A 70 yr + right hip said to me “no more kick starting” so an electric thumb 70’s 750 Honda was my choice. I have made a Cafe bike out of the bike building a fibreglass mould for a cafe seat and side covers.