Yep, your engine is definitely a 2000/2001 5JJ. That 'unit' behind your exhaust headers is the AIS system, which the 98/99 4XV engine's didn't have. They used the same casings though, hence the 4XV stamped in places.

The hose leads from the inlet manifold to the AIS unit to operate the vacuum diaphragm.

Just unplug that from the inlet manifold, block the hose off with a hose clamp or suitable plug and hook up your carb balancing tool to that manifold spigot and the other cylinder's takeoffs. Balnace as normal then connect the hose back up when you're done

 

That's a bit of good news, thanks a lot for the help

After a quick search on AIS systems & finding a crapload of "how to remove the AIS" threads on other sites, what exactly is the advantage of removing the AIS system other than reducing exhaust popping?

 

No worries for the help

Removing the AIS system, good thing to do. There's no disadvantages.

You'll lose a good bit of weight, little bit smoother throttle response and the popping that you know about.

I notice that your bikes not quite the cleanest, so be careful undoing any bolts/exhaust manifold studs and blocking the AIS exhaust port spigots is the trickiest bit. The How To's cover that though

 

Thanks a lot for the info, the only disadvantages I found on my quick search was that the AIS reduces exhaust emissions so may go for my MOT beforehand just incase. The bike has gone through 30k miles so not in the best shape now, always try my best to restore / replace most parts though! Also already run through a lot of rounded heads, snapped heads on bolts etc, used to it and have the tools to get around these issues now!

 

Are you in the UK?

You mentioned an MOT that's why I'm asking.

 

i'm tipping he is for sure.
just the way he types words. plus the 5jj reference.
only you guys call them that in general terms.

 

Yep, in the south east (east sussex to be exact)

 

:lol :thumbup

 

it's ok. we're safe in here. moderators never give help in these sections!:hammer::hammer::vanish:vanish:vanish

 

Yeah,carb #1 is fixed,you adjust the other 3 by its setting