Carb choice between stock 34 and 38

[Capt_Zoom]

I'm trying to decide which set of carbs to use on my wife's bike. I have two sets

-Stock 34mm from 1980, look brand new and will need to be rebuilt, jetted, and canadian needles (I have all the parts for this). I think I have a good set of boots. Would need new air pods.

-Stock 38mm from 1977, look dirty as heck, work, but might need to be rejetted for short pipes. I have working boots. and air pods

This is for the wife's bike so I want a good reliable performer. Which carb is more reliable?

 

[5twins]

I don't think there would be any difference in reliability. Both are good carb sets. The 34s are a more modern design and lighter. The 38s might be easier to tune.

 

[Patches]

Really, there is no need for the Canadian needles, but I believe that the BS34 will prove to be the carb of choice. The 1980's are a little unique in that they have brass floats and different bowls, but I believe they are the ones that make it possible to change the main jet with out removing the carbs from the bike.

BS38's are fine carbs, but I have had slightly better luck tuning the 34's. Also I personally believe they have better throttle response (maybe it has something to do with having a smaller diaphram). Yes, they may not flow as many CFM's but we are dealing with diaphragm carbs here and they will basically only give the motor as much air as it wants.

Just my 2 cents.

In terms of reliability, you'd be fine with either. They both have outstanding aftermarket support, parts are cheap (fairly) and easy to come by.

My wife's bike is going to have a set of Lectrons but that's just because I'm wanting to be fancy pancy....

 

[gggGary]

I am slightly in favor of the 34s I prefer the main jet being higher in the float bowl especially on a bike that may sit a while between uses. The smaller 34mm venturi probably helps the bike run smoother in "normal" part throttle use. If your wife is the drag racer type ignore that.......... Foam floats are a nice toss in upgrade on the 80's