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Scooters - 125 to 300 => Downtown 300 => Topic started by: Yoni159 on February 22, 2020, 02:54:00 PM

Title: Oil leak from cranckcase sensor or something...
Post by: Yoni159 on February 22, 2020, 02:54:00 PM
I got oil leak from sensor or something i dont know what it is its above the cranckcase.
https://imgur.com/a/0k0pq3S
Title: Re: Oil leak from cranckcase sensor or something...
Post by: CROSSBOLT on February 22, 2020, 03:17:11 PM
Pretty messy, will have to clean off really well then watch to see where it starts coming out.
Title: Re: Oil leak from cranckcase sensor or something...
Post by: Yoni159 on February 22, 2020, 03:50:22 PM
I know where it comes from its comes from the black wire on the cranck case you can see i the picture on the left side you could see a black wire. But why its leaking?
Title: Re: Oil leak from cranckcase sensor or something...
Post by: Yoni159 on February 22, 2020, 06:03:45 PM
Update its a stator wire.. but what can i do to stop the leak?
Title: Re: Oil leak from cranckcase sensor or something...
Post by: scooterfan on February 22, 2020, 07:32:56 PM
It doesn’t look that bad. Probably just a slight oil “sweat” at a seal which started long ago. If there is no oil dripping on the floor I would just clean everything an keep an eye on it more regularly in future.
Title: Re: Oil leak from cranckcase sensor or something...
Post by: Yoni159 on February 22, 2020, 07:54:39 PM
Its not look bad because i cleaned it . But i can put a rtv glue around it?
Title: Re: Oil leak from cranckcase sensor or something...
Post by: mousejunks on February 22, 2020, 09:47:30 PM
This happens when the plastic stator connector goes brittle from heat and then oil leaks out. There is no gasket around that connector so the leak is inevitable.

You can use a gasket maker such as Permatex Black for maximum oil resistance.
Title: Re: Oil leak from cranckcase sensor or something...
Post by: scooterfan on February 23, 2020, 07:15:42 AM
The plastic stator connector is probably just a lower point at the housing and I don't think it normally gets in contact with oil. The oil is probably leaking at the crankshaft oil seal, or an engine gasket elsewhere. If so it might be better to leave the stator connector as is. If the leak is bad and you seal the connector properly I think oil might start building up inside the housing and this could cause more problems.
Title: Re: Oil leak from cranckcase sensor or something...
Post by: Yoni159 on February 23, 2020, 09:23:04 AM
This happens when the plastic stator connector goes brittle from heat and then oil leaks out. There is no gasket around that connector so the leak is inevitable.

You can use a gasket maker such as Permatex Black for maximum oil resistance.
is it safe? The glue cant get inside ?
Title: Re: Oil leak from cranckcase sensor or something...
Post by: mousejunks on February 23, 2020, 09:29:06 AM
Definitely leaking from the plastic plug/insert that holds the stator wires and crankshaft position sensor. I have attached a pic that shows the plastic insert relative to the crankcase cover. There is a thin paper gasket runs all around the edge of the cover except the plastic part. There is no gasket or sealant around that area. It simply goes hard from heat and oil can leak out while the engine is running.

I wouldn't worry about to much, oil can't leak quickly since it is on the top. Clean it and apply gasket maker. If you ever take the crankcase cover off, the gasket maker will work better for the leak but the paper crankcase gasket will rip, so get a replacement beforehand.

Source: 80,000 km on a DT300i and my new DT350i is starting to show a smear from the same location.
Title: Re: Oil leak from cranckcase sensor or something...
Post by: mousejunks on February 23, 2020, 09:30:52 AM
is it safe? The glue cant get inside ?

No, once the gasket maker cures it is tough and flexible. The gap is too small for gasket maker to go inside.
Title: Re: Oil leak from cranckcase sensor or something...
Post by: Yoni159 on February 23, 2020, 09:49:23 AM
Definitely leaking from the plastic plug/insert that holds the stator wires and crankshaft position sensor. I have attached a pic that shows the plastic insert relative to the crankcase cover. There is a thin paper gasket runs all around the edge of the cover except the plastic part. There is no gasket or sealant around that area. It simply goes hard from heat and oil can leak out while the engine is running.

I wouldn't worry about to much, oil can't leak quickly since it is on the top. Clean it and apply gasket maker. If you ever take the crankcase cover off, the gasket maker will work better for the leak but the paper crankcase gasket will rip, so get a replacement beforehand.

Source: 80,000 km on a DT300i and my new DT350i is starting to show a smear from the same location.
thanks for the explanation. Rtv glue works fine too?
Title: Re: Oil leak from cranckcase sensor or something...
Post by: mousejunks on February 23, 2020, 08:24:19 PM
Yes, just make sure it is suitable for engines