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Royal Enfield Motorcycles => Vintage Royal Enfield => Topic started by: AB55TB on May 03, 2013, 03:21:27 am

Title: Oil coming out of breather, on 700 twin
Post by: AB55TB on May 03, 2013, 03:21:27 am
Well seems we have a super meteor instead of a trailblazer, but I removed timing cover an found a rubber seal damaged really bad on the bolt that goes in the end of the crank,I think this may be why the oil
Is getting into the crank housing...does any one agree that this rubber seal is the culprit ?
Title: Re: Oil coming out of breather, on 700 twin
Post by: Arizoni on May 03, 2013, 05:16:51 am
I haven't been inside a RE twin but just as a point of information, most of these 4 stroke engines supply the oil to the connecting rod big end bearings by pumping oil into the crankshaft on the timing side.
Because the oil pump is pumping oil into the rotating crankshaft a oil seal is needed there to keep the oil going where it is intended instead of being just blown out on the cam/crank gears.

If I am right, leaving the damaged seal could starve your rod bearings and the cylinder walls from getting a good supply of oil.

As for this causing extra oil to accumulate in the crankcase I don't see how it could.
As I mentioned, the seal isn't to keep oil out of the crankcase, it is there to make sure oil gets into the crankcase thru the rod bearings.
Title: Re: Oil coming out of breather, on 700 twin
Post by: High On Octane on May 03, 2013, 05:39:34 am
Have you done a compression or leak down test on the cylinders?  When the piston rings get badly worn it can cause excessive blow by.  And I agree with Arizoni about needing to replace that seal.  In fact, I hate to say it, but if that seal is that badly worn, you may want to consider doing a tear down and overhaul.   :(    Give the engine a very thorough examination and make sure everything else is in working order and come up with a plan from there.  All the parts are available through Hitchcock's.

Scottie 

Are you having any other issues with it running?
Title: Re: Oil coming out of breather, on 700 twin
Post by: ERC on May 03, 2013, 01:13:14 pm
Arionzi is correct on that.  ERC
Title: Re: Oil coming out of breather, on 700 twin
Post by: barenekd on May 03, 2013, 10:35:12 pm
the oil is pumped through the filter, the routed through passages in the case to the end of the crankshaft, where the seal is, and up to the lifters and valves. hte most important one is the one that goes to the end of the crankshaft. That one feeds the main bearings, rod bearings and oils the  cylinder walls and crankpin with the oil, by splash, as it comes out of the bearings. If that seal is damaged it could stop some or all of the oil from going into the crankshaft. this can lead to great difficulties.
The top end oil goes through another passage is in unaffected by the seal.
I'm not really sure what you mean about the oil going into the crankcase. Oil should go into the crankcase, but it also should be pumped out by the scavenge side of the pump. What symptoms are you getting that oil is going the wrong place? Does the engine have any clunking noises? Questions for a nosy mind and a source of data to figure out what is really going on here.
As for the Super Meteor and Trailblazer, they are the same bike less some minor appearance changes, like handlebars, the casquette headlight was on the 54 or 55 and later Brit models, not the Indians, the mufflers may have varied a bit.
Very minor stuff. The numbering was probably the same. It was a cheap conversion.
Title: Re: Oil coming out of breather, on 700 twin
Post by: AB55TB on May 07, 2013, 05:34:55 pm
All u guys are great, I am having a time with it though... It runs good for about ten min, then I can shut it down an check the oil an it will be between the high an low marks, then start it up an then the smoke starts an then it starts spitting out out the breather..between 7to10 min... Of runnining,before that runs great no smoke or oil no where...lol
Title: Re: Oil coming out of breather, on 700 twin
Post by: AB55TB on May 07, 2013, 05:57:45 pm
To barenekd...well I've just been reading that the engine can be wet sumping, so I don't really understand it says it has a regular oil tank, then it has a place for the oil to go when it wet sumps, but this motor only has one oil plug on the lower right hand side,an it has a screen on it.. An also the metal tube that runs inside the oil fill spout what is its purpose, I just figured since the level was going down pretty quick while the engine is running its going into this other tank I've read about, not understanding that part yet.
Title: Re: Oil coming out of breather, on 700 twin
Post by: High On Octane on May 07, 2013, 07:01:52 pm
The tube inside the filler neck isis the oil return.  Out should be pumping oil out of that tube when the bike is running.  If it isn't your return oil pump had failed.

Scottie
Title: Re: Oil coming out of breather, on 700 twin
Post by: AB55TB on May 24, 2013, 11:11:54 pm
Ok... I have replaced all there is to replace on the oil pump, both discs, spindle, an new oil filter an all internal parts there, an also bowed air through the ports why all was apart, the return pump on the front of the motor is building up pressure an pushing oil out the end cap gasket on the pump,an I'm still not getting oil out of my return tube...I feel that this pressure building up is filling the crank case to the point it's going out the breather, cause it can't return to the oil tank...I need help in what to do next, it seems as if there is a blockage somewhere....can some of you enfield master mechanics point me in the right direction as what to do :)
Title: Re: Oil coming out of breather, on 700 twin
Post by: AB55TB on May 24, 2013, 11:23:39 pm
Ok... I have replaced all there is to replace on the oil pump, both discs, spindle, an new oil filter an all internal parts there, an also bowed air through the ports why all was apart, the return pump on the front of the motor is building up pressure an pushing oil out the end cap gasket on the pump,an I'm still not getting oil out of my return tube...I feel that this pressure building up is filling the crank case to the point it's going out the breather, cause it can't return to the oil tank...I need help in what to do next, it seems as if there is a blockage somewhere....can some of you enfield master mechanics point me in the right direction as what to do :) also would like to know if there is a website I can go on or a PDF so I can find a better service manual, we have got one for this bike but it does not go Into detail like i was hoping.
Title: Re: Oil coming out of breather, on 700 twin
Post by: High On Octane on May 25, 2013, 12:37:58 am
The PDFs are towards the bottom of the first page in this topic.

http://www.enfieldmotorcycles.com/forum/index.php/topic,15603.0.html

Scottie
Title: Re: Oil coming out of breather, on 700 twin
Post by: rotorwrench on May 25, 2013, 03:43:23 pm
The oil system on a Royal Enfield twin is  a unique system and has always been a source of tension with owners. The two warnings I can give you are old ones relating to making any kind of modifications. The first is the bobbin seal has to be servieable or the con rods will end up on the ground with a hole in the case. The bobins can be modified but you have to know what works there or just stay with the rotating neoprene rubber seal. The second warning is never change the pump pistons & disks without knowing exactly what will work and which end it goes on. The return pump is larger than the pressure pump for a reason. Never swap them or damage to the engine will occur. Don't use late pumps on older engines unless you talk to an experienced Enfied mechanic about what will work and what will not.

The oil tank is part of the engine case behind the crankcase and all the passages are internal to the case. There is a pickup screen in the bottom of the crankcase that can get coated with old interior crankcase paint or other crud. There is access to the oil ports with the timing cover removed and there are several cap plug screws to cap off drilled oil passages. You will need an old shop manual to see a diagram of the system. A parts break down can also help some to explain how things work in there but not all manuals have good exploded views.
Title: Re: Oil coming out of breather, on 700 twin
Post by: ERC on May 25, 2013, 07:33:36 pm
Pay attention to what Rotor say's, he's right on the money about messing around with this system.  ERC
Title: Re: Oil coming out of breather, on 700 twin
Post by: ERC on May 25, 2013, 07:52:16 pm
Here's a diagram of what your system basically looks like.  ERC