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General Category => General Discussion => Topic started by: samfrank on August 09, 2020, 01:08:55 PM

Title: oil leak '73 Eldorado
Post by: samfrank on August 09, 2020, 01:08:55 PM
I was out riding a few weeks back and the bike started to lurch/hesitate. I pulled into a gas station and noticed a serious oil leak coming from the air filter housing area. I added some oil to get me home. I don't consider myself very mechanically astute but I checked some things out. The air filter was in serious need of replacing. I did that. I'm not sure if a fouled air filter would lead to an oil leak. I don't understand the mechanics of the oil recirculating system. The mechanic I HAD replaced this oil breather a few years back but not with OEM equipment.  Any ideas on what to look for or where to start would be greatly appreciated. I've got way too much $ into this bike and not really to looking at pouring more into it.
Thanks

Sam Frank
Title: Re: oil leak '73 Eldorado
Post by: nick949 on August 09, 2020, 01:26:59 PM
Had you over-filled it? 3 litres only or it will puke.

Nick
Title: Re: oil leak '73 Eldorado
Post by: Antietam Classic Cycle on August 09, 2020, 04:04:42 PM
On Loopframe Guzzis the engine breather and air filter are two totally separate systems, not connected in any way (at least not from the factory). If the breather wasn't replaced "OEM equipment" then what was installed? A photo might help.

It could be "the mechanic" replaced the breather box with one with a working disk-type check valve and added a Tonti-style ball-type check valve as well. If so, they can work against one another and cause oil to be ejected from the engine.

Perhaps it's nothing more than a burst breather hose.

However, neither of the above would cause it to lurch/hesitate. 
Title: Re: oil leak '73 Eldorado
Post by: moto-uno on August 09, 2020, 04:16:34 PM
 ^+1 , possibly if the air filter itself was saturated in oil it could sure throw the running off , no ?  Peter
 As above pics are always a help.
Title: Re: oil leak '73 Eldorado
Post by: Antietam Classic Cycle on August 09, 2020, 04:53:43 PM
^+1 , possibly if the air filter itself was saturated in oil it could sure throw the running off , no ?  Peter
 As above pics are always a help.

Assuming stock air box, it would be very difficult to saturate the filter. The breather isn't connected to it in any way and the only openings are small louvers on the sides and holes in the bottom. Oil would have to blow up from underneath, or blow back through the carbs to get inside.
Title: Re: oil leak '73 Eldorado
Post by: samfrank on August 09, 2020, 06:49:53 PM
Here are a few pics of the breather and air filter


(http://<br />[url=https://ibb.co/SvcNtbp][img]https://i.ibb.co/SvcNtbp/B167-DDDE-AF12-41-B4-B513-CAA7-FBF298-A8.jpg)[/url]

(https://i.ibb.co/m4P9YFZ/5-C2-E3034-EEAA-4311-977-F-78256827-C432.jpg) (https://ibb.co/m4P9YFZ)
[/img]
Title: Re: oil leak '73 Eldorado
Post by: Antietam Classic Cycle on August 09, 2020, 07:24:06 PM
Everything I posted above is made irrelevant by that photo. I'm not sure what breather box that is, something "custom". It looks like there's a second one back above the voltage regulator with a hose right into the air filter housing. So, the air filter could definitely be saturated with that system and that would definitely cause it to lurch/hesitate. How it's all supposed to work is something only the guy that built it knows.
Title: Re: oil leak '73 Eldorado
Post by: Furbo on August 10, 2020, 04:01:17 PM
Don't think I've ever seen an Eldo with the original filter still in place....
Title: Re: oil leak '73 Eldorado
Post by: TOMB on August 10, 2020, 06:54:55 PM
It looks like a variation of an Agustoni breather from the LeMans bikes, and used incorrectly,


TOMB
Title: Re: oil leak '73 Eldorado
Post by: moto-uno on August 10, 2020, 06:58:51 PM
 Nice colour matching on the intake manifolds ! Peter
Title: Re: oil leak '73 Eldorado
Post by: Antietam Classic Cycle on October 21, 2020, 08:39:35 PM
Sam's Eldo is here at the shop now and I've started digging into it. The breather system is quite bizarre - the box itself is quite nice - reed type valve in top, but the rest is a bit of a mess. It's all removed and will be replaced with a standard Loop breather box.

The hose going through the airbox is the oil return.

(https://i.ibb.co/KhHkwQp/OLYMPUS-DIGITAL-CAMERA.jpg) (https://ibb.co/KhHkwQp)

It snakes around the right side of the box...
(https://i.ibb.co/Hp3qdTw/OLYMPUS-DIGITAL-CAMERA.jpg) (https://ibb.co/Hp3qdTw)

...and hooks up to the return line on the top of the engine.
(https://i.ibb.co/YNc8sSh/OLYMPUS-DIGITAL-CAMERA.jpg) (https://ibb.co/YNc8sSh)

A couple of extra holes in the airbox.
(https://i.ibb.co/Nt8SKSJ/OLYMPUS-DIGITAL-CAMERA.jpg) (https://ibb.co/Nt8SKSJ)

This is inside the top of the airbox.
(https://i.ibb.co/NjP0fdF/OLYMPUS-DIGITAL-CAMERA.jpg) (https://ibb.co/NjP0fdF)

Connections poking out the back.
(https://i.ibb.co/YXZ7QQZ/OLYMPUS-DIGITAL-CAMERA.jpg) (https://ibb.co/YXZ7QQZ)

Why would you put a jet into the oil return circuit to restrict flow?
(https://i.ibb.co/KFHWgNv/OLYMPUS-DIGITAL-CAMERA.jpg) (https://ibb.co/KFHWgNv)

All of it removed.
(https://i.ibb.co/9GtPKLH/OLYMPUS-DIGITAL-CAMERA.jpg) (https://ibb.co/9GtPKLH) (https://i.ibb.co/WVFwwgj/OLYMPUS-DIGITAL-CAMERA.jpg) (https://ibb.co/WVFwwgj)

Reed valve in the top of the breather box.
(https://i.ibb.co/d6frZ5x/OLYMPUS-DIGITAL-CAMERA.jpg) (https://ibb.co/d6frZ5x)

Someone went to a lot of trouble to rotate the top of the box from it's original orientation.
(https://i.ibb.co/Ldyss8C/OLYMPUS-DIGITAL-CAMERA.jpg) (https://ibb.co/Ldyss8C)
Title: Re: oil leak '73 Eldorado
Post by: Antietam Classic Cycle on October 21, 2020, 10:14:46 PM
I've never had any "expulsion of oil" unless I filled to the 3 liters specified in the manual. 3 quarts and there's been zero problems over more than 100,000 miles. <shrug>

There's a Harper's/Pertronix Ignitor in the distributor.
Title: Re: oil leak '73 Eldorado
Post by: Antietam Classic Cycle on November 01, 2020, 09:19:45 AM
Original type breather installed.

(https://i.ibb.co/cX3jxGJ/OLYMPUS-DIGITAL-CAMERA.jpg) (https://ibb.co/cX3jxGJ)

Title: Re: oil leak '73 Eldorado
Post by: fotoguzzi on November 01, 2020, 10:30:36 AM
That looks a lot less cluttered.
Title: Re: oil leak '73 Eldorado
Post by: Antietam Classic Cycle on November 01, 2020, 10:35:28 AM
And it won't pump oil into the air filter.
Title: Re: oil leak '73 Eldorado
Post by: stmike on November 01, 2020, 02:29:18 PM
One of our riding crew had one of these awhile back. We affectionately called it Moto Valdez.
Title: Re: oil leak '73 Eldorado
Post by: Antietam Classic Cycle on November 01, 2020, 03:26:44 PM
One of these what? If you mean an old Eldorado, they're no more likely to leak than any other Guzzi and if they do, need to be repaired. Simple.
Title: Re: oil leak '73 Eldorado
Post by: Cam3512 on November 01, 2020, 03:50:04 PM
Much better.  Making a living unfarking other so-called “mechanics” handy work.  Lotta job security out there!