FJowners.com

General Category => Maintenance => Topic started by: fuel80guy on February 23, 2014, 03:37:25 PM

Title: Vacuum lines
Post by: fuel80guy on February 23, 2014, 03:37:25 PM
Got my carbs back for my 85 and got stumped on vacuum lines.
My bike is an american bike and while replacing o rings on boots i came across 4 vacuum lines.
#1 goes to tdi box and#2 and #3 are looped together joining boots.
However #4 goes out of top of boot but i cant find where it attaches to anything.
Am i missing a part that the PO threw out?
Im told its a california bike.
Rob
Title: Re: Vacuum lines
Post by: Pat Conlon on February 23, 2014, 04:26:26 PM
Hi Rob, on my '84 Calif model I've disconnected the vacuum lines (and capped them at the carbs)  that run to the charcoal canisters, part of the vapor recovery system used on Calif model bikes.

I have also disconnected/capped the vacuum line to the TCI ignition module (off #2) this is also part of the emissions control system and does not affect the performance of the bike.

So now I have only 1 vacuum line in use:
#1 cylinder goes to the vacuum petcock. (#1 cylinder is far left as you are sitting on the bike)

#2, #3 and #4 at the manifold are capped off. Use the heavy rubber oem Yamaha caps with the spring collars.
It's hot on that engine side of the heat shield and this temp. will split the thin walled automotive vacuum caps

So, oem vacuum lines are like this;
at the intake manifold: #1 petcock, #2 TCI,
at the carbs: ( vacuum ports) #2 and #3 to the charcoal canisters... Hope this helps. Pat
Title: Re: Vacuum lines
Post by: fuel80guy on February 23, 2014, 06:07:11 PM
Hey Pat
So no vacuum line is needed to run to TCI module?
Do you need to cap fitting on module?
Thank you so much for your imput.
Rob
Title: Re: Vacuum lines
Post by: FJmonkey on February 23, 2014, 07:03:29 PM
No cap required for the module.