freefly103
VIP MEMBER
- Joined
- Apr 17, 2013
- Messages
- 285
Been putting a few miles on the '70 since the top end rebuild. Bike is running well, but have noticed a leak from the tach drive that's more annoying than anything else. Not a lot of oil leaking from there, but enough to have to clean it up after a ride.
The '70 has a camshaft breather. Upon inspection, the hose shows no signs of any blow back to the oil tank i.e. the hose is clear and the breather appears to be functioning but the pressure and leak is manifesting itself at the tach drive and not being released via the breather. I changed the oring in the tach drive body and installed another between the nut where the cable meets the drive body, but that has made little difference. I'd like one of Jim's reed breathers but to dismantle the engine and send the crankcase to the US to have it machined and installed is a bridge too far at this stage. An electronic tach with the analogue drive port blanked off will be the next step. That doesn't solve the inherent problem though, just the current symptoms.
Should the camshaft breather be an effective solution to the crankcase pressure build up or is it a useless design feature?
The '70 has a camshaft breather. Upon inspection, the hose shows no signs of any blow back to the oil tank i.e. the hose is clear and the breather appears to be functioning but the pressure and leak is manifesting itself at the tach drive and not being released via the breather. I changed the oring in the tach drive body and installed another between the nut where the cable meets the drive body, but that has made little difference. I'd like one of Jim's reed breathers but to dismantle the engine and send the crankcase to the US to have it machined and installed is a bridge too far at this stage. An electronic tach with the analogue drive port blanked off will be the next step. That doesn't solve the inherent problem though, just the current symptoms.
Should the camshaft breather be an effective solution to the crankcase pressure build up or is it a useless design feature?