"boost sensor" vac line ?

[bald josh]

its a long story so the question is... on the vac line to the vacuume sensor as it should be called, there is a small plastic piece that couples two pieces of vac line tiogether. there is an arrow on that piece that points towards the carb, or toward the sensor???

I have been fighting an extremely annoying problem for some time now that i think may be related to this part and its orientation in line.

Im gonna cry if its just a matter of the stupid thing being in the wrong way... its almost always a very easy fix, made alot more difficult by our own over thinking....

[Squeeze]

The Arrow points towards the Sensor.

[Venturous Randy]

Josh, what are your symptoms?

RandyA

[bald josh]

the bike hesitates and surges very, very mildly. took it to the mc mech and put it on the dyno. didnt see anything for a while then he noticed the timing on #2 cyl was all over the place and #4 was a bit crazy too. ive put my replacement tci in and no change, so i replaced pickup coils. took it for a test ride yesterday and no change.i had replaced the boost sensor when prob first came up the sensor/timing has always been in the back of my mind so i fiddled with it. plugged the line( no vac to sensor ) bike ran HORRIBLE, then turned the plastic piece around so arrow pointed to sensor, and it seemed better, but at that point i was in traffic, close to home, and slick roads, so i was more focused on stayin alive. got home and looked at my 86 and found the arrow pointing toward sensor on it.

Im gonna test ride again when time permits but maybe all i did was put that dumb part in backwards, it seems so hard to believe that it would make that much difference but...

 

thanks for any help!!!

[Condor]

That plastic connector is nothing more than a vacume pulse smoother outer . Smooths out the vacume pulse to the sensor. It also can become clogged and cut way back on sensor response... My 2¢

[bald josh]

thanks for the info, if it smoothes out the pulses, and has an arrow on it i would think it would make a difference wich way the arrow points. seems minor but maybe it will make that big of a difference.

[dingy]

I have one of the boost sensor lines in my hand.

 

The plastic restrictor is a straight through opening. No baffles or valving that I can see.

 

Flow seems to be the same through it in both directions by blowing into either end.

 

The shorter, larger diameter hose goes to the carb intake boot.

 

Gary

[Texaskid]

BJ, you might want to see which cylinder your vac line is hooked up to. On my 89 it is hooked to the number 2 cylinder. I have hooked it to number 1 but it ran not to good.so I hooked it to number 2 where it is suppose to be.

[bald josh]

pretty sure its on #2, forward left cyl sitting on bike...