Boost sensor restrictor-83 Venture

[Oldgold]

I think I've seen mention of a restrictor in the vacuum line to the boost sensor, does anyone know for sure if there is one and where is it located ?

[hipshot]

dave, on my '86, it is located "inline" on #2 carb. about three of four inches up from where the vac.tube attaches to the carb.

on mine, there is a noticeable "insert", and i believe it is marked with a small white arrow.

not sure how an '83 is set up, though.hope this helps.

just jt

[Denden]

There wasn't one on my '83 when I bought it from the 2nd owner with 32k miles on it. I'm pretty sure that it was completely stock at that point. Since only the '83 uses vacuum from the base of the #2 carb (differnt from all other years), I don't think there is supposed to be a restrictor in the line.

[Dano]

As I understand it, the 83's vacuum line comes from the intake side of the carb (above the carb), and the 84 & up bikes come from below the carb. I'm not sure if it's a restrictor or a gate valve to keep the vacuum in the line.

[Denden]

As I understand it, the 83's vacuum line comes from the intake side of the carb (above the carb), and the 84 & up bikes come from below the carb. I'm not sure if it's a restrictor or a gate valve to keep the vacuum in the line.

it's not a gate valve, it's a restrictor, or "snubber". It's purpose is to even out the peaks in the vacuum pulses. The carb syncronizers use the same thing in the lines, whether it's a mercury stick sync tool, or the Carbtune.

[Dano]

Larn' sumtin new every day! Thanks Denden. More knowledge means smarter wrenches!

Dan

[Oldgold]

Thanks for the quick response, my 83 had about 9000 miles on it when I got it years ago and I was never able to locate a restrictor. As Denden

notes the 83's take off above the throttle plate so perhaps this location

provided enough of a restriction since the vacuum would be much lower than later models which draw manifold vacuum. I did a test splice in line with a .007 HVAC restrictor and was able to see voltage change on a digital meter, test ride showed some difference in throttle response,nothing dramatic.