Quote from: FJ1200W on November 03, 2025, 07:30:33 AMI must be the exception as I have never had an issue with the stock slave cylinder.

I never really had an "issue" with mine, just since the bike clicked over 100,000 miles and slave cylinder maintenance periods were getting a bit closer together, I thought "why not give it a try" - plus, the big reason behind it all was................ MODITIS.

I've changed or upgraded the forks, brakes, 17" wheels, yokes, rear shock, FZ1 bars, FZ1 mirrors, Remus exhaust, modified fenders/mudguard, all the lights are LED, FJR clutch master cylinder, FZ1 brake master cylinder, span adjustable levers, all braided hydraulic lines, K & N air filter, iridium plugs (for longer life), the list goes on and on........

And I was getting the itch to change/improve something else (I'm not a fan of the spin on oil filter swap, just happy with the stock affair).

Probably the next thing I'll upgrade/change is the oil cooler, but maybe I'll wait for that until I decide to give the engine a big bore kit and some tuning - the only thing is, I'm loathe to take the engine apart while she's still running so well and reliably.

I'm really struggling to find any other worthwhile bits I can add/change on the bike to improve it, or make it more "my bike" (I've also already also got crash bars and a full Krauser luggage system, and a usb socket for charging "things" on the move).

Despite all the changes, 99% of other bikers think my bike is stock when they see it 

Thanks yet again for sharing your knowledge. Just capped of the vacuum fitting at the TCI box.

For comparison my FJ1200 has high flowing pod air filters, stock headers and open wide mouth mini-mufflers. I'm running 45 pilots and 120 mains. I admit I'm rich on the pilots but I had trouble getting the 42.5's dialed in and the 45's are working fine. The 120 mains are great, I could probably go up a size from there but rarely riding in that throttle range. I run HSR Dyna springs and HSR tapered needles with needles on the 3rd clip from the top, bike runs great and for me it's most important the bike is dialed in for the mid range between 3k-6k rpm and this set up is spot on for me. I rarely let the bike idle except at stop lights and rarely go past 3/4 throttle except for maybe a few seconds, the bike has so much torque I have no need to twist the throttle that much.

Pat is right in his starting point and then you can dial it in from there based on symptoms.

Very good!

The vacuum ports you have to worry about are the 4 ports on the intake manifold.
2 of the 4 ports are occupied by the vacuum line to your petcock and vacuum line to the TCI box, the other 2 ports should be capped with the heavy rubber oem Yamaha caps and clamps. Don't use thin walled vacuum caps you can get at your auto parts store. The heat in that location will destroy light duty caps...you need the heavy walled oem caps, with clamps.

The TCI box (Transistor Controlled Ignition) on your '84 has a vacuum line that is part of the advance system for smog, and can be capped off with no issues. Often the diaphragm in the TCI box rots out and then leaks unmetered air into your intake manifold.
 Do the suck test on this vacuum line. You should not be able to suck any air into this vacuum line. If so, cap it off.
Here's more reading on the TCI and DCI vacuum lines. : https://fjowners.com/index.php?topic=11690.0

If you have a Calif. model you have a vent on the carbs #1 and #4 that are connected to the two charcoal canisters that fuel tank vapors draw into. They should be capped if not used.

The downward facing ports on your carbs are the choke vents (not vacuum) They draw air into the choke circuit only when the choke is activated. You need short 14" hose lines on those ports running to the back of the engine.
You will also notice 2 larger hoses connected to T's between carbs 1/2 and 3/4, those are your fuel bowl vents, those also should have hose lines running to the back of the engine. Don't plug, kink or pinch these choke vents or bowl vent hose lines.

Good move on getting those carbs to Robert at RPM.

Hope this helps.

Pat

Welcome Juan! I glad that poor bike is in your hands now.

Cheers

Pat

Quote from: Millietant on November 03, 2025, 05:59:03 AMYou could try the FJR master cylinder, they also come with a span adjustable lever so you can position the lever and take up Point where it's comfortable. I've not used my Oberon with a FJ master cylinder so can't comment.

Thanks Dean, I'll give that a try.  Steve, glad you are having good luck with the stock slave.  I've owned the bike since almost new and it gave me trouble early.

I almost did something I didn't need to do -

"Most excellent!"

I must be the exception as I have never had an issue with the stock slave cylinder.