ET: Engine (Twin) What Happens If The Breather Tube Timing Has Gone Wrong?

[CarlHungness]

I have just attempted to check the position of my rear camshaft and followed the instructions given here previously as to when the Intake valve should be fully open
and I'm disappointed all seems to be well. I checked it with my degree wheel and it
is opening at the proper point.
So, it is possible my breather tube timing has shifted and I'll check it tomorrow.
I do have the instructions on when it should open and close, so once again will
check with the degree wheel.
Am still searching for the problem that is keeping the bike from starting and haven't
located it yet. I installed my old ATD at 6 degrees BTDC with the ears closed and still
no luck, so am trying to figure out what else inside the case may have shifted, gone
out of time, etc.

 

[rapide049]

I have just attempted to check the position of my rear camshaft and followed the instructions given here previously as to when the Intake valve should be fully open
and I'm disappointed all seems to be well. I checked it with my degree wheel and it
is opening at the proper point.
So, it is possible my breather tube timing has shifted and I'll check it tomorrow.
I do have the instructions on when it should open and close, so once again will
check with the degree wheel.
Am still searching for the problem that is keeping the bike from starting and haven't
located it yet. I installed my old ATD at 6 degrees BTDC with the ears closed and still
no luck, so am trying to figure out what els

I have just attempted to check the position of my rear camshaft and followed the instructions given here previously as to when the Intake valve should be fully open
and I'm disappointed all seems to be well. I checked it with my degree wheel and it
is opening at the proper point.
So, it is possible my breather tube timing has shifted and I'll check it tomorrow.
I do have the instructions on when it should open and close, so once again will
check with the degree wheel.
Am still searching for the problem that is keeping the bike from starting and haven't
located it yet. I installed my old ATD at 6 degrees BTDC with the ears closed and still
no luck, so am trying to figure out what else inside the case may have shifted, gone
out of time, etc.

The only way this can shift is You , when fitting the ATD , might be time to take it to your mate Glen Bewley and leave it with Him to rectify everything you have played with

 

[davidd]

David

 

[CarlHungness]

View attachment 59981

David

Those are the exact notes I have and will check tomorrow. I understand it is possible for something
to give way and possibly upset the timing of the device. I took it out years back, widened the slot
and also got another 1/16" from the oulet tube.

 

[Pushrod Twin]

I have just attempted to check the position of my rear camshaft and followed the instructions given here previously as to when the Intake valve should be fully open
and I'm disappointed all seems to be well. I checked it with my degree wheel and it
is opening at the proper point.
So, it is possible my breather tube timing has shifted and I'll check it tomorrow.
I do have the instructions on when it should open and close, so once again will
check with the degree wheel.
Am still searching for the problem that is keeping the bike from starting and haven't
located it yet. I installed my old ATD at 6 degrees BTDC with the ears closed and still
no luck, so am trying to figure out what else inside the case may have shifted, gone
out of time, etc.

Carl, I dont believe that a mis-timed breather will prevent your engine from running. On my twin the aluminium bush inside the breather pinion seized on the breather spindle and the pinion rotated around on the bush. It blocked the breather port right off and the bike continued to run satisfactorily for a long time before I had the cover off to change the magneto and noticed the metalflake mess in the timing chest. It didn't even leak any more oil that normal.
I think you have bigger issues to chase.

 

[CarlHungness]

Carl, I dont believe that a mis-timed breather will prevent your engine from running. On my twin the aluminium bush inside the breather pinion seized on the breather spindle and the pinion rotated around on the bush. It blocked the breather port right off and the bike continued to run satisfactorily for a long time before I had the cover off to change the magneto and noticed the metalflake mess in the timing chest. It didn't even leak any more oil that normal.
I think you have bigger issues to chase.

That's a disappointing reply, and appreciated. I've run out of options on what to check next. I went to a lot of work years back to widen the breather slot per Phil Irving recommendation too.