Oil Loss

[FiferWD]

I have a continuing problem with disappearing oil at higher speeds (higher than 50mph).  I have the free flow exhaust and air cleaner on my 2005 ES with 18 tooth sprocket.  The slightest blockage in my breather tube will cause oil to squirt out of the timing case tube, on one occasion thick enough to cover the windshield of the car foolish enough to stay behind me in the right lane of Rte 301.

I have blocked off the tube from the timing chest, but oil still seems to disappear at the rate of about a pint in 20 to 30 miles when I am riding above 50 mph.  To paraphrase the old song, I just "Put a little oil in the old saddle bags and ride, ride, ride!" but I would like to find a better solution.  Has anyone tried the Bunn Breather on a Bullet?

Yrs,
Bill in Bethesda Maryland

[CMW-Rhett]

Hi Bill,

Welcome to the forum. I wish that I could help but (like so many questions) this one is a bit beyond me. I've forwarded your inquiry to our tech guys.

[HRAB]

Some of the things that have been tried are fairly simple. The object is to keep a negative pressure in the engine. If it becomes pressurized, oil will pump up the timing chest tube. That tube is intended to return any oil from the catch can to the engine.

 The modification kits work. The modified breather tube for the timing side cover contains a check valve that will help prevent pumping of oil up the tube.

The simple things:
frequently check the breather tube from the top of the tank to the catch can. It can plug with a mix of oil and water vapor as a material that looks like mayonaise. One person claims that this tube can be re-routed to eliminate the sump in the middle of it by routing it over the frame member with success in reducing the build up. Check the duck bill inside the catch can to be sure the snap clip isn't holding it open. Ad an automotive PVC valve in this line to augment the duck bill.

Over filling the oil is another primary cause of the loss of oil. Check the level cold. It should be below the midpoint on the dip stick. Check the oil hot after the bike has been off for a few minutes to be sure it isn't over full when hot.

[FiferWD]

Some of the things that have been tried are fairly simple. The object is to keep a negative pressure in the engine. If it becomes pressurized, oil will pump up the timing chest tube. That tube is intended to return any oil from the catch can to the engine.

At this point I have blocked the return tube and installed a brass drain cock in the catch can to facilitate draining the goo.  I cleaned off the engine and bike thoroughly, which enables me to get a better idea of where the oil is going.  So far, I have seen no evidence of it going through the catch can, nor do I see any signs of weeping.  I also replaced all the hose clips with real screw type hose clamps.  While it is no longer escaping through the breather network, oil is still disappearing.  With 10,000 miles on the odometer, I am beginning to wonder if my rings are letting oil be burnt.  After having adjusted the valve pushrods, I can stand on the starter without losing compression, though.  I replaced the plug last week and found that the old one was pretty crusted with carbon, but it had been in there for about 6,000 miles.  I haven't looked at the new one yet.

[dewjantim]

Sounds like you need rings or valve guides. 10,000 is quite a few miles on these old 50's style motors. Most of the British engines from this era needed rebuilding (at least top end) at about 10,000 miles. Dew.

[gapl53]

I have a continuing problem with disappearing oil at higher speeds (higher than 50mph).  I have the free flow exhaust and air cleaner on my 2005 ES with 18 tooth sprocket.  The slightest blockage in my breather tube will cause oil to squirt out of the timing case tube, on one occasion thick enough to cover the windshield of the car foolish enough to stay behind me in the right lane of Rte 301.

I have blocked off the tube from the timing chest, but oil still seems to disappear at the rate of about a pint in 20 to 30 miles when I am riding above 50 mph.  To paraphrase the old song, I just "Put a little oil in the old saddle bags and ride, ride, ride!" but I would like to find a better solution.  Has anyone tried the Bunn Breather on a Bullet?

Yrs,
Bill in Bethesda Maryland

Blocking the tube from the timing chest will make matters worse because it is the return route for the oil that the positive pressure in the crankcase has pushed to the catch can under the seat. Make sure all the hoses are clear. You can blow them out with an air hose, and then check, the airbox and air filter for excessive oil contamination. You may need to replace the filter if it is oil soaked. Then follow HRAB's advice he hits it on the head.

[lunar]

I have 350Machismo from 2000. I only have breather tube, without any duck bill or valve -
Lost it somewhere on the road...  

So, now I have straight rubber hose.

Can I improvise this or should I get new breather tube with valve of some kind?

Motor runs normally, does not spit oil (few drops).

Any advice?

Thank you in advance!

[little_a_o]

I looked into my setup and I have an alluminum plug in my timing chest tube.  My breather tube goes to the can (air-filter housing). 

My question is, where would the timing tube connect to?

2006 Military

Little ao

Blocking the tube from the timing chest will make matters worse because it is the return route for the oil that the positive pressure in the crankcase has pushed to the catch can under the seat. Make sure all the hoses are clear. You can blow them out with an air hose, and then check, the airbox and air filter for excessive oil contamination. You may need to replace the filter if it is oil soaked. Then follow HRAB's advice he hits it on the head.

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[mbevo1]

Little ao - my '07 Bullet has three hoses attached to the catch-can.  One from the middle of the top of the crankcase, the other to the timing case on the right side of the motor. The third tube runs over to the airbox to vent gases back into the intake air.   I guess some of the previous versions only had the crankcase line and a drain valve in the bottom of the catch-can. The duckbill (primative but effective one-way valve to maintain slight negative crankcase pressure) is inside the catch-can connected to the crankcase line.

The timing case return line is designed to route condensed oil from the catch-can back to into  the motor.  The old RE design had an outflow tube from the crankcase (my motor has a stub at the base of the cylinder on the left side that was the original port) that terminated in a duckbill  over the chain.  Any oil (and other combustion by-products) blown out would be run down over the chain.  Automatic chain-oiler.  There was no return line to the timing chest in this configuration.  The catch-can and return line were added to eliminate the drips from the duckbill so we wouldn't pollute our pristine planet...  problem is, many of us don't want the glop going back into the oil supply, and the system can get gunked up fairly easily.  When the duckbill or return line get gunked up with condensed oil/water/etc. "mayo", negetive crackcase pressure can be lost and the bike will start blowing out a bunch of oil from wherever it can push it out.  If enough stuff gets blown into the catch-can, it will start pumping over to the airbox and will plug up the air filter.

I split the timing case hose and blocked the return line with a dowel.  Left the other end attached to the catch-can and blocked it with a dowel, too.  My configuraion keeps the catch-can and the vent to the airbox, but blocks the return line.  I have to drain and clean the catch-can regularly, but I had to do that anyway. 

Many bulleteers go back to the original configuration with the just crankcase line and duckbill and remove the catch-can completely.

[little_a_o]

Mike and others;

Well I think my catch can has been retired from the bike by the previous owner being that I don't see one on the bike.  My crank case vent pic below shows the tube entering right into the air box to make its journey through the intake.  I pulled the box and removed the tube to test for blockage.  The valve seems to be allowing suction and a slight amount of oil can be seen at the carb's inlet. 

I'm still concerned since I am dealing with a messy oil  loss around the engine.
I'd like to unplug the timing case vent hose and see if that eases the oil leakage situation. 

Can they both be vented directly overboard  (environmentally aside)  or does it require a certain amount of restriction for proper operation? 

Thanks Little ao

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[deejay]

Mike and others;

Well I think my catch can has been retired from the bike by the previous owner being that I don't see one on the bike.  My crank case vent pic below shows the tube entering right into the air box to make its journey through the intake.  I pulled the box and removed the tube to test for blockage.  The valve seems to be allowing suction and a slight amount of oil can be seen at the carb's inlet. 

I'm still concerned since I am dealing with a messy oil  loss around the engine.
I'd like to unplug the timing case vent hose and see if that eases the oil leakage situation. 

Can they both be vented directly overboard  (environmentally aside)  or does it require a certain amount of restriction for proper operation? 

Thanks Little ao

Since it looks like it's on your tappet cover i would check the head gasket, maybe re-torque the head.

[Kevin Mahoney]

We do offer a free replacement tube from the timing chest to the can for those of you who do not have the proper type. The correct type has a larger diameter for a cuople of inches after the tube leaves the timing chest. it has a one way valve built into it.

[little_a_o]

Thanks,

I Re-torqued  the head and rode roughly 35 miles today.  Looks better.

Little AO

Since it looks like it's on your tappet cover i would check the head gasket, maybe re-torque the head.

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[little_a_o]

Oil loss is still a problem and I have turned it over to the dealer to look it over.  Oil dissapears at a rate of about 1 pint per 80 miles when operated at a sustained 55 mph.

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[Foggy_Auggie]

My same problem - one time oil blowout into the air cleaner - was caused by a thick white sludge blocking both hoses going into the under seat catch can.  This blockage created a pressure causing the smaller hose from the timing chest to blowback into the catch can - filling it and then overflowing into the short hose to the air cleaner box.

The fix was removing the seat.  Taking apart the catch can. Removing both large and small diameter hoses from the can and the engine.  Then pushing a rod through the hoses - rinsing kerosene through the hoses, then air blowing dry.

There was a thick white sludge in the center of both hoses.  Caused by moisture congealing with the oil residue.  I think this started on the freight ship across the Pacific in the shipping crate.  As this problem was early on within the first couple hundred miles of riding.

After the above procedure and changing the oil and filter at 300 miles this problem has never occurred again.  Although stop and go short trips and not getting up to sustained operating temperature may cause residue to return -  I don't do short hops.

Regards, Foggy