o0norton0o
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- Joined
- Apr 27, 2015
- Messages
- 1,738
I also have a 70 commando with a timed cam breather. I just recently decided to do the timing chest reed valve modification after researching all the options. Like many people, I didn't want to rebuild my engine and have the added expense of the comstock breather modification, although everything about it seems like the best option.
I have 2 3/8ths holes from the timing chest into the crankcase to allow air movement and a 1/4 inch hole drilled behind the oil pump to allow oil to drain back to the crankcase from the timing chest.
I mounted the mikes's reed valve on a flat blanking plate and replaced the stock dished blanking plate on the back of the timing chest. I routed the the pipe to a Tee so it connects to the cam breather hose right before it enters the oil tank.
Everything works really well so far. I can't believe my bike finally doesn't leak oil anywhere. I always had the typical commando leaks with this bike ever since I rebuilt it 30 years ago. I am pretty happy with the results...
I have pictures of my modification too, let me see if I can upload them...
breather holes are red arrows
oil drain hole is yellow arrow
reed valve hole is green arrow
I have a single question about blocking off the timed breather since I have seen numerous people mention the same advise . My question is, Why do people say you need to block off the timed cam breather once you install the timing chest reed valve???
It seems to me that it's fine just the way it is, as a secondary route for air pressure to escape the crankcase. Logically, I think 2 places to vent crankcase pressure would work better than one...
.... comments please... thanks
I have 2 3/8ths holes from the timing chest into the crankcase to allow air movement and a 1/4 inch hole drilled behind the oil pump to allow oil to drain back to the crankcase from the timing chest.
I mounted the mikes's reed valve on a flat blanking plate and replaced the stock dished blanking plate on the back of the timing chest. I routed the the pipe to a Tee so it connects to the cam breather hose right before it enters the oil tank.
Everything works really well so far. I can't believe my bike finally doesn't leak oil anywhere. I always had the typical commando leaks with this bike ever since I rebuilt it 30 years ago. I am pretty happy with the results...
I have pictures of my modification too, let me see if I can upload them...
breather holes are red arrows
oil drain hole is yellow arrow
reed valve hole is green arrow
I have a single question about blocking off the timed breather since I have seen numerous people mention the same advise . My question is, Why do people say you need to block off the timed cam breather once you install the timing chest reed valve???
It seems to me that it's fine just the way it is, as a secondary route for air pressure to escape the crankcase. Logically, I think 2 places to vent crankcase pressure would work better than one...
.... comments please... thanks