Author Topic: Eliminating the catch tank under the battery box  (Read 854 times)

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Offline timtune

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Eliminating the catch tank under the battery box
« on: January 02, 2022, 04:40:46 PM »
I'm getting my 76 750F slowly back together. In order to clean things up visually I'd like to scrap some of the ugly venting and overflow hoses including the plastic catch can under the battery box.

Can some of this be replaced by a short hose with a small K&N filter mounted? Is there much oil? Any help greatly appreciated.

Thanks.

Offline Alan F.

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Re: Eliminating the catch tank under the battery box
« Reply #1 on: January 02, 2022, 05:36:46 PM »
I understand that you'd need to check a filter regularly for fear it'd clog up with dirt and stop venting.

Offline 70CB750

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Re: Eliminating the catch tank under the battery box
« Reply #2 on: January 03, 2022, 03:33:31 AM »
I'm getting my 76 750F slowly back together. In order to clean things up visually I'd like to scrap some of the ugly venting and overflow hoses including the plastic catch can under the battery box.

Can some of this be replaced by a short hose with a small K&N filter mounted? Is there much oil? Any help greatly appreciated.

Thanks.

Red has 78F engine and I routed the top breather hose to the secondary chain, if there is any oil coming out it drips on the chain.  I never had any problems with it.  The bottom hose connects from the back of the engine to the oil tank port.
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Offline Don R

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Re: Eliminating the catch tank under the battery box
« Reply #3 on: January 03, 2022, 08:01:24 AM »
 I used a K&N type filter, it eventually dripped oil. I moved it up higher on a hose and ended up back to stock. I had also connected the oil tank vent to the hose for a while too. That might just be my bike though, it was a fresh 836.
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Offline timtune

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Re: Eliminating the catch tank under the battery box
« Reply #4 on: January 03, 2022, 05:43:07 PM »
Thanks All.

Don R did you hook both the valve cover and rear case vents to the same hose? Any reason that would be problematic?

Should I expect some oil to dribble from both those vents?

Offline Tracksnblades1

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Re: Eliminating the catch tank under the battery box
« Reply #5 on: January 03, 2022, 08:42:20 PM »
I’d be interested in purchasing your OEM breather if it’s complete and in good condition.
I have the K&N breather with the rag under the seat to lay under it after a ride. 🤔
Your complete air cleaner box too, if it’s perfect.
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Offline timtune

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Re: Eliminating the catch tank under the battery box
« Reply #6 on: January 04, 2022, 07:39:40 AM »
I have extra air boxes if you need one. Shipping from Ontario Canada???

Offline scottly

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Re: Eliminating the catch tank under the battery box
« Reply #7 on: January 04, 2022, 08:35:22 PM »
Thanks All.

Don R did you hook both the valve cover and rear case vents to the same hose? Any reason that would be problematic?

Should I expect some oil to dribble from both those vents?
The spigot on the rear case is connected to a like sized spigot on the oil tank. This hose drains oil from the oil/air separator inside the tank into the case, and will have oil dribbling through it. It should not be connected to the vent hose from the valve cover. Earlier bikes had the cover vent tube routed over the carbs and down on the right side near the swing-arm pivot. 
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Offline BomberMann650

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Re: Eliminating the catch tank under the battery box
« Reply #8 on: January 05, 2022, 10:12:24 PM »
Seems tempting to plug a one-way breather valve on the end of the hoses.

Offline Don R

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Re: Eliminating the catch tank under the battery box
« Reply #9 on: January 06, 2022, 12:38:07 PM »
Thanks All.

Don R did you hook both the valve cover and rear case vents to the same hose? Any reason that would be problematic?

Should I expect some oil to dribble from both those vents?
It is an issue, oil leaked everywhere even when I added a filter vent to the top of it. I didn't know where those hoses were supposed to go back then and tried the connection. There was no pressure vent. My K0 doesn't leak all over with the hoses going down to the swingarm area. Even the 836 engine.
No matter how many times you paint over a shadow, it's still there.
 CEO at the no kill motorcycle shop.
 You don't need a weatherman to know which way the wind blows.