Honda GB400 cam doesn't have a centre journal oil hole?

[ShotgunNZ]

Just pulled out my cam and noticed some massive scoring on the centre journal and corresponding cam area. This is typical for a head that's been lacking oil. Must be some supply issue.

My cam has an oil hole per cam lobe but doesn't have one to lube the centre journal. Does anybody know if all GB400 cams are like this? It seems crazy that there wouldn't be an oil hole there. This means it only gets oil that's sloshing round in the head, which isn't likely to be much.

I can confirm that XR600s definitely do have an oil hole for the centre journal. As for the GB500 and other RFVC family engines, I have no idea.

Can anybody shed any light on this?

[Flip]

GB 400's always used to chop out the cams. Regular oil changes, semi synthetic oil and keeping the head temp down extends the cam life. You have me confused as you in one paragraph talk about a journal and a cam follower in the next. If its done a cam and follower in Cam-tek used to hard face the follower and regring the cam for me for a very resionable price. They used to put a trail bike profile on them and they always went better after thay had been done. I had about 8 of these bikes as courier bikes many years ago. You can get 2 or 3 regrinds from a cam. The cam lobe dips itself into oil each revolution. Hope this helps.

[ShotgunNZ]

I worked out why the cam centre journal hole wasn't visible. There was so much damage that the hole was filled by about 3mm of metal and nicely covered in scoring. Must've got progressively worse until the hole was blocked off and then center journal ran unlubricated. Talk about exponential failure!

Anyway, it's XR600 engine time. Spending dollars on keeping the 400 engine going seems a bit silly.