Try our new info resource - "Aladdin's Cave" (Main menu)Just added a separate link to Ash's Dropbox thread (shortcut)
I just emailed Castrol about ma spec oil and they replied I don’t know if the info is any help
I no it’s odd the gtx oil is the last thing to try this is a page from Honda workshop manual from the 70s if this doesn’t sort it looks like I will have to take engine out and look at gearbox I don’t know what else it could be