Oil Pump

[Gav]

Hey. My ZXR750 dosent seem to get oil to the top end on start up for a few seconds, is this normal ? Maybe oil pump? Something more sinister?. 46,000 on the clock. This bike gets new oil & filter every 5000..Cheers

[robracer]

How are you checking this?
Oil has to travel from the sump to the head so it will take a few seconds to pump through the oil galleries anyway

[Gav]

When I start it up it just seems to rattle a bit at the top end till the oil arrives, after that it shuts right up. I dont want to have problems later with cam bearings flogging out. Yeah I dont know to much about this motor...

[timmyrocks]

what viscosity oil are you using? seeing as its colder the oil will be thicker and harder for the oil pump to pick up, therefore will take longer to get to the head, a few seconds will be fine, although maby try a thiiner oil

[Byproduct]

Sounds like the cam chain is getting a bit loose. Mine did this for a fair while, really loud rattle for 10-30 secs. Then one day it stopped doing it, must have been the chain adjuster clicked out a notch. It was much quieter on cold starts from then on but i didn't use that engine much longer after it happened. New engine doesn't have the rattle at all

I've read camchins typically need repacing in these every engines 35-50k depending how they have been treated. I have also found that warming the bike up at full vertical makes the startup rattle dissipate much quciker. The camchain is on the right had side of the engine so when warming up on the sidestand the cold thick oil takes much longer to reach the top end. Always sit on the bike for at least that first 30 secs of warmup, your top end will thank you