GB600R oil feed problem - ideas please

[masterofpuppets]

hi all,

over the last few months i have been tinkering in the garage neatly every night putting an XR600R motor into a GB400 frame. the motor had a blown big end, so had to strip the whole thing down and do a full rebuild. Got the motor in the frame, and have been fiddling with electrics - till i finally got it running tonight.

i wanted to make sure oil was feeding thru ok, so i undid the banjo bolt on the oil feed to the head... and waited.. and waited... and waited... and no oil pressure. so i thought maybe the oil pump is sucking in a whole lotta air, so i opened one of the caps on the rocker cover, and poured in a bunch of oil thinking it will lubricate the cam and submerge the oil pump to prime it. so i ran it for about another minute, and still no oil pressure to the head.

these motors run a dry sump system. the oil tank was half full before i got it running. after the two runs it was all full. my guess is that the oil pipes to and from the oil reservoir are reversed, so oil is running the wrong way thru the system. then again i would have thought that the pumps on the gb400 and xr600 are similar.

any ideas would be appreciated.

regards,
Nik

[Grumph]

Find an XR600 and check the pipe runs...
If it's the way you have it now then you'll have to investigate why it's not pumping.

Had this happen on a TT Yamaha - someone had left off the plate between the case halves which seals off one side of the pump - mistakes like this are easy to do.