Engine Breather:
I am re-commissioning my recently-acquired Navigator and noticed that, when kicking the engine over (without the spark plugs in place) the âhuffingâ from the breather is very loud. This led me to wonder whether the breather and its associated pipework had been installed correctly â for example, should it have been vented into the primary chaincase or should it have been directed through some sound-muffling rubber hose arrangement onto the secondary chain in the vicinity of the gearbox final drive sprocket, which is the general area from which the huffing sounds appear to emanate. Neither the parts book nor the ownersâ manual offer any diagram or other clear description of the breather arrangement, apart from a brief list of components, none of which are illustrated. I suppose that the arrangement would be revealed if I removed the primary chaincase but that would be a time-consuming procedure that Iâd rather avoid if possible.
I would be grateful for any advice or photoâs throwing some light on what to expect in the engine breather department. Also, I wondered whether anyone had experimented with improving the breather arrangement because, just at the moment, my bikeâs system sounds as if it could be gulping into the crankcase just as much crud from the area around the final drive chain as it might be venting later in the engineâs cycle.
The breather should be pip…
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Previously tim_gostling wr…
Previously tim_gostling wrote:
The breather should be piped back to the oil tank, on the delux there is a connection for the breather pipe just below the cap in the filler neck of the tank, I imagine the standard oil tak has a similar arrangement. (The oil tank then has it's own breather which just vents to atmosphere to release the pressure) Without this pipework you will hear the pressure being pushed out of the breather when the pistons fall & a certain amount being sucked back in as the pistons rise.
The breather can be modified by drilling down through the casing just behind the barrel to break into the breather port & adding a fitting to attach the breather pipe, then blanking the original outlet by the final drive sprocket, the breather pipe then exits from above the casting. The main advantage is to allow the use of a larger final drive sprocket to improve the gearing, the disadvantage is it's not so neat & hidden. I don't think it makes any difference to the breathing of the engine.
HTH, Regards, Tim
Here's a picture of that area
Attachments breather-93912-jubilee-jpg breather-resiting.JPG- Log in to post comments
Previously andy_sochanik w…
Previously andy_sochanik wrote:
Attachments breather_1a-jpgPreviously tim_gostling wrote:
The breather should be piped back to the oil tank, on the delux there is a connection for the breather pipe just below the cap in the filler neck of the tank, I imagine the standard oil tak has a similar arrangement. (The oil tank then has it's own breather which just vents to atmosphere to release the pressure) Without this pipework you will hear the pressure being pushed out of the breather when the pistons fall & a certain amount being sucked back in as the pistons rise.
The breather can be modified by drilling down through the casing just behind the barrel to break into the breather port & adding a fitting to attach the breather pipe, then blanking the original outlet by the final drive sprocket, the breather pipe then exits from above the casting. The main advantage is to allow the use of a larger final drive sprocket to improve the gearing, the disadvantage is it's not so neat & hidden. I don't think it makes any difference to the breathing of the engine.
HTH, Regards, Tim
Here's a picture of that area
***And here a picture of the stoopid breather pipe that gets damaged the very first time you shut the trottle! Note that on engines after 106838 (& all Electra) do not have this.
The breather is untimed - just a hole to atmosphere - so the noise you hear is the air being displaced below the pistons.
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Previously andy_sochanik w…
Previously andy_sochanik wrote:
Previously andy_sochanik wrote:
Previously tim_gostling wrote:
The breather should be piped back to the oil tank, on the delux there is a connection for the breather pipe just below the cap in the filler neck of the tank, I imagine the standard oil tak has a similar arrangement. (The oil tank then has it's own breather which just vents to atmosphere to release the pressure) Without this pipework you will hear the pressure being pushed out of the breather when the pistons fall & a certain amount being sucked back in as the pistons rise.
The breather can be modified by drilling down through the casing just behind the barrel to break into the breather port & adding a fitting to attach the breather pipe, then blanking the original outlet by the final drive sprocket, the breather pipe then exits from above the casting. The main advantage is to allow the use of a larger final drive sprocket to improve the gearing, the disadvantage is it's not so neat & hidden. I don't think it makes any difference to the breathing of the engine.
HTH, Regards, Tim
Here's a picture of that area
***And here a picture of the stoopid breather pipe that gets damaged the very first time you shut the trottle! Note that on engines after 106838 (& all Electra) do not have this.
The breather is untimed - just a hole to atmosphere - so the noise you hear is the air being displaced below the pistons.
Thanks, Andy & Timfor the extra, pictoral advice. I've reinstated the original breather arrangement for now, although I've added a non-return valve in the pipe leading back to the oil tank on the premise that, at low revs at least, it ought to reduce the mean crankcase pressure in the hope that leaks will be suppressed.
In the meantime, I've diverted onto refurbishment of the Roadholders, which on strip-down were revealed to have been lubricated by a smidgeon of skanky grease rather than oil. Miraculously, the wear hasn't been excessive, so new stanchions, bearings and seals and of course some oil or ATF should restore the situation. The bodges some idiots do!!
Anon, Ian.
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The breather should be piped back to the oil tank, on the delux there is a connection for the breather pipe just below the cap in the filler neck of the tank, I imagine the standard oil tak has a similar arrangement. (The oil tank then has it's own breather which just vents to atmosphere to release the pressure) Without this pipework you will hear the pressure being pushed out of the breather when the pistons fall & a certain amount being sucked back in as the pistons rise.
The breather can be modified by drilling down through the casing just behind the barrel to break into the breather port & adding a fitting to attach the breather pipe, then blanking the original outlet by the final drive sprocket, the breather pipe then exits from above the casting. The main advantage is to allow the use of a larger final drive sprocket to improve the gearing, the disadvantage is it's not so neat & hidden. I don't think it makes any difference to the breathing of the engine.
HTH, Regards, Tim