Author Topic: After a winter in the basement...discovered where oil leak coming from.  (Read 3312 times)

Chris0381

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Well after sitting a winter in the basement, I discovered  where that pesky 2T oil leak was coming from that was dripping down the carb-gas reservoir hose. Its actually coming past the o-rings of the 2T oil senor that fits in the oil reservoir.

Am I putting too much oil in the res? I would think not as that is the reason for the o-rings. Wondering if I should empty the res and wipe off the o-rings to where they are bone dry and reinstalling them may stop the leak. After all, it plastic against o-rings and I can imagine the tolerances not too good with those parts.

Other solution would be to just keep the level below the o-rings.
2013 Super 8 50cc 2T Air Cooled Mfg'd 2012
Stock pipe derestriction
Smooth Boss
6.5gm Dr Pulley sliders
Malossi Torsion Controller
Malossi Fly Clutch- yellow springs
Polini Variator
#95 Main Jet
Purple Malossi Contra Spring
42 MPH on the flats with the wind

kimura

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BettinANDlosing

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OOOO that sucks, the only thing to do is replace the oil sending unit or get a plug and get rid of the oil sensor (Bad idea). I've seen this happen mostly on china made bikes. Usually it comes out of where the wires come into the sensor, and I've tried many different kinds of sealers, glue, epoxy JB weld etc to fix this and nothing worked except getting a new sensor for ~$40.
2002 Kymco B&W 300; MRP 78MM "300CC", Naraku cam, Yoshimura rS3 exhaust, 17g Sliders, Yellow torque spring drilled airbox, stock carb #115 main #40 pj.

2001 "Yamaha" Zuma AKA MBK Booster; MHR OverRange, Dellorto 19mm BHBG, Polini "big" intake, RS-3 Rear shock, Stock cylinder.

Chris0381

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THAnks Bettin

I can try a few things.

Keep the level low an fill frequently, make a dispstik oil cap.

See if cleaning and drying may form a seal - feeling you tried that.

Bigger or fatter o-ring.

Maybe some duct tape on the inside of the reservoir hole to reduce the I.D. that the o-rings fit to.

Go to the auto parts store and get an expandable freeze plug.

Since its fed to the bottom of the res, the fluid has to go quite low before non gets to the engine.
Right now I just wrap a rag around it and change the rag every week as its a very slow leak.

I see a sensor on ebay but I have a feeling its on ebay because of the same problem. If it seal via o-rings, I assume the o-rings play a big part but could be the reservoir was blow molded on a hot day and didnt cool properly. I used to design blow molds and summer was a disaster for production runs as the bottles dont cool properly and lose tolerances. Helen Curtis used to scream at us when their shampoo bottle shoulders didnt hold .005 inches.

Ill work something out.
« Last Edit: March 18, 2015, 07:55:59 PM by Chris0381 »
2013 Super 8 50cc 2T Air Cooled Mfg'd 2012
Stock pipe derestriction
Smooth Boss
6.5gm Dr Pulley sliders
Malossi Torsion Controller
Malossi Fly Clutch- yellow springs
Polini Variator
#95 Main Jet
Purple Malossi Contra Spring
42 MPH on the flats with the wind

Chris0381

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2013 Super 8 50cc 2T Air Cooled Mfg'd 2012
Stock pipe derestriction
Smooth Boss
6.5gm Dr Pulley sliders
Malossi Torsion Controller
Malossi Fly Clutch- yellow springs
Polini Variator
#95 Main Jet
Purple Malossi Contra Spring
42 MPH on the flats with the wind

Chris0381

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After spending this morning drilling andtapping new CVT cover threads, I took a close look and the oil reservoir.

He is what I think the solution to the leak is:

There is plenty of volume below the o-rings for oil supply so simply dont fill it above the oil sensor o-rings. If you look at the bottom of the reservoir cover cap, you will see a hole in it. Simply press fit a tube of some sort in that hole, make a level mark on the tube and use that as a dipstick so you can keep an eye on the oil level as the reservoir its self is white and hard to see through to see the oil level.

Dont fill above the o-rings.
Make a dipstick to get a sense of the oil level so its not too high.


2013 Super 8 50cc 2T Air Cooled Mfg'd 2012
Stock pipe derestriction
Smooth Boss
6.5gm Dr Pulley sliders
Malossi Torsion Controller
Malossi Fly Clutch- yellow springs
Polini Variator
#95 Main Jet
Purple Malossi Contra Spring
42 MPH on the flats with the wind

Chris0381

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No o-rings there its just a plug type of seal. Just took oil out so oil isn't at the level of the seal.

Forefinger finger dry - could use some oil.

Pinky finger wet - too much oil.

Actually by looking at the system and judging how deep the sensor bottom sits, I can guess that if the oil light just comes on, you still have quite a ways to go until the outlet feeding the manifold/carb begins to suck air. I would never solely depend on the oil light coming on to tell me to fill up on some 2T oil.

I may be wrong, don't hold me on that. Ill do my best to keep the level just below the sensor seal.
« Last Edit: March 24, 2015, 05:08:01 PM by Chris0381 »
2013 Super 8 50cc 2T Air Cooled Mfg'd 2012
Stock pipe derestriction
Smooth Boss
6.5gm Dr Pulley sliders
Malossi Torsion Controller
Malossi Fly Clutch- yellow springs
Polini Variator
#95 Main Jet
Purple Malossi Contra Spring
42 MPH on the flats with the wind

BettinANDlosing

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Good call. yeah the Oil light comes on at about 1/2 tank or a little less on most 2t scoots, plenty of reserve. I think the designers figure people don't act on a bright red light right away (true in my experience). One thing to look out for that I just remembered, look out for cracks around the oil sending unit. There was one bike I worked on that I even tried a new sending unit and it still leaked then I ended up taking the bottle out and looking super close and there was a small hairline crack that would leak 2t when the reservoir was full. If you decide to get a new unit, I can help you get the right part. PM me if you'd like a quote. Also about the duct tape, I tried all of that and the only permanent solution was a new sending unit, I think one of those "stop plugs" would work though I never tried that.
2002 Kymco B&W 300; MRP 78MM "300CC", Naraku cam, Yoshimura rS3 exhaust, 17g Sliders, Yellow torque spring drilled airbox, stock carb #115 main #40 pj.

2001 "Yamaha" Zuma AKA MBK Booster; MHR OverRange, Dellorto 19mm BHBG, Polini "big" intake, RS-3 Rear shock, Stock cylinder.

Chris0381

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Thanks Bettin

Ill inspect the unit more when bring it up from the dark basement in a week or two. Really good points.

Thanks again.
2013 Super 8 50cc 2T Air Cooled Mfg'd 2012
Stock pipe derestriction
Smooth Boss
6.5gm Dr Pulley sliders
Malossi Torsion Controller
Malossi Fly Clutch- yellow springs
Polini Variator
#95 Main Jet
Purple Malossi Contra Spring
42 MPH on the flats with the wind

Chris0381

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I should add if you ever do run you bike to where the oil light comes on and you want to try and make it to a place to get more 2T oil. Be careful of tilting the bike to a point where the bottom of the res is exposed allowing air to get drawn into the pump.

Or could you introduce air into the oil system by dumping you bike even with a mostly full res ?

I'm not sure on any of this.
« Last Edit: March 27, 2015, 01:58:39 PM by Chris0381 »
2013 Super 8 50cc 2T Air Cooled Mfg'd 2012
Stock pipe derestriction
Smooth Boss
6.5gm Dr Pulley sliders
Malossi Torsion Controller
Malossi Fly Clutch- yellow springs
Polini Variator
#95 Main Jet
Purple Malossi Contra Spring
42 MPH on the flats with the wind

AgileWhitey

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Re: After a winter in the basement...discovered where oil leak coming from.
« Reply #10 on: March 27, 2015, 02:48:05 PM »
Just a quick idea. Use teflon tape wrapped behind the o ring groove. It expands the diameter of the oring once installed. I work in a tool repair shop and we use this little trick on nail guns.
The captain sinks with the ship..... (why am I the only one left swimming)

Chris0381

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Re: After a winter in the basement...discovered where oil leak coming from.
« Reply #11 on: March 28, 2015, 12:44:21 PM »
Upon further inspection, there are no o-rings but ridges on a plug I thought were o-rings at one point.

Not sure if the plug or reservoir is bad. Im still under warranty but the dealer is about 40 miles away and I wont lug my bike there unless something more serious is happening.


« Last Edit: March 28, 2015, 12:47:03 PM by Chris0381 »
2013 Super 8 50cc 2T Air Cooled Mfg'd 2012
Stock pipe derestriction
Smooth Boss
6.5gm Dr Pulley sliders
Malossi Torsion Controller
Malossi Fly Clutch- yellow springs
Polini Variator
#95 Main Jet
Purple Malossi Contra Spring
42 MPH on the flats with the wind

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