Dependable screamer fond of oil
Although the five-valve four is high-revving and has a fairly high oil consumption rate (expect to get through a litre every 1000 miles – so keep an eye on the level), it’s essentially solid with no problems.that said, watch out for blue smoke, oil leaks and any deposits in the end-can as all are sure signs of trouble ahead.
Yamaha’s EXUP valves are known to get sticky whatever model you’re dealing with and theyzf is no exception. Make sure the servo motor turns when you switch the ignition on. It’s located inside the frame rail under the base of the tank on the right side. You should hear a tell-tale whirr.at the same time check the cables running to it move freely and correctly.
THEYZF’S clutch, like manyyamahas of the period, isn’t its strongest suit, even more so because of the strain the 750’s performance puts it under.any example over 20,000 miles is likely to need a replacement, so budget accordingly.the six-speed gearbox is generally sound if notchy but second gear in particular is prone to wear.
Aftermarket exhausts rarely improve the performance of theyzf and more often than not actually reduce its flow as back pressure is critical, especially if the EXUP valve is removed with a full system. Even if just a race can is fitted, beware – the EXUP valve means that carbs will need careful setting up.
Although theyamaha Deltabox is fairly solid it’s easily damaged and is susceptible to that as so manyyzfs have ended up on track. Inspect carefully and beware of polished frames.they may look shiny but are often buffed to remove evidence of damage.
Front six-pot calipers are OK if looked after, but like many calipers of the era are prone to seizing if neglected, although they do free up fairly easily.the calipers’ tendency to seize also means warped discs are not uncommon. Check for pulsing through the lever and aftermarket replacements.
The location of most of the electrical gubbins under the seat means they’re right in the line of spray from the back wheel and thus prone to early corrosion.when inspecting ensure you remove the seat and check around the battery tray area very thoroughly.
The speedometer cable on theyzf750 is prone to working loose at the drive end with the result being a clicking or jumpy speedo needle – or one that doesn’t work at all. If left to run when notchy the inner cable can be damaged and break although it’s simple and fairly cheap to replace.
The earliest models have a switch on the left-side fairing inner panel for fuel reserve. Check that it’s connected up and working properly as otherwise you’ll be running in the reserve position and will be liable to run out of fuel.
As with mostyamahas of the period the YZF’S finish in some areas isn’t the best with flaky white wheel paint and corrosion-prone fasteners and fork sliders the worst culprits. You won’t have to look hard to spot it: any bike that’s been at all neglected will stand out a mile away. Questionable DIY paintjobs and nasty aftermarket anodised bolts abound.