Anyone know where to get a 5jj engine need one ASAP none on ebay. .

Try malc at yorkshire engines theres not much he doesnt have

Full 4xv package in for sale section, not sure on differences?

I have a 4xv complete with carbs and a k+ N filter and uprtated clutch up for sale for the right price I can throw in a spare engine for rebuilding and a manual

as far as I am aware the 5jj has a slightly better gearbox and runs injection instead of carbs but they should be interchangeable I may be wrong however

stand corrected according to my Haynes manual there on carbs its the 5pw's that are on injection

I think the main differences is in the gearbox as said, but the 5jj also has an emission re circulation contraption that I don't think the 4xv has. No doubt there's a few tweaks in the ecu etc too.

From Wikipedia


At 127.8 horsepower (95.3 kW) at the rear wheel, top-end output remained the same, but changes to the engine management system were intended to result in a smoother, broader distribution of power.

Mechanically, the carburetors were re-jetted in an effort to improve throttle response, especially in the low end, all the way up to the bike's 11,750 rpm redline. The redesigned camshafts were lightened and used internal oil ways to lubricate journals that, when combined with reduced tappet clearance, provided less friction and created less engine noise. The gearbox received a taller first gear, a hollow chrome-moly shift-shaft with an additional bearing and a completely redesigned shift linkage and foot pedal. These changes were aimed at eliminating problems with the transmission in earlier models, and to help to seamlessly transfer the bike's power to the road.

David