Gearbox filled with petrol

[Stein]

Hello!

 

I just found 1 1/2 litre of petrol in my gearbox..!!

Have any of you experienced something like this and know the cure?

 

 

Here the facts:

 

-Newly rebuild motor.

-T5 autolube motor.

-T5 original SI carburettor for autolube, but autolube is disconnected and closed by removing small gear by clutch, axle and closing oil tube inside carb housing. Oil channel in carb housing closed With glue.

-New float needle.

-Original valve inlet.

-SIP fastflow fuel tap. Seems to Close/open correctly.

 

 

Scooter have been hard to start and flows over. Have not managed to drive for more than 5-600 meters before it dies. It smells of petrol and it seems to be overflowing in some way. 

 I first discovered that fuel was leaking out from  mixer screw hole on the carb housing and whole top of carb was wet. I changed all gaskets and it seemed to be leaking much less, but strangely it was difficult to remove all leaking. Due to fastflow fuel tap, perhaps?

 

Have tested for leaks with letting fuel tap stay both on and off overnight. Sometimes carb top have been dry, sometimes wet.

 

Fuel have also been dripping from one of the T5 exhaust bolts, and I pressumed fuel was following the fuel line or so, but after checking I saw that connection of fuel tap to tank and fuel hose to fuel tap is tight and dry.

 

It was wet of petrol on top of the gears schalter box, and I was more than supprised when I removed the box and petrol was flowing out.

The petrol inside filled up 2 wine bottles!

 

I assumed that it was via a damaged metal oil seal by the crank that the petrol found its way to the gearbox, but to my supprice when separating the motor yesterday, all seals looked to be like they should and I see no cracks in the casings.  

 

So, before I start pressure testing or throwing the casings away, I want to ask if anyone of you might know what is happening.

 

Thanks in advance!

 

Regards from Norway,

 

Stein

 

 

[fgib98]

It could be the Shaft seal in the Clutchside

Gesendet von meinem Nexus 7 mit Tapatalk

[sammba]

Hello Stein,

 

what you wrote makes sense.

The only possibilities for the fuel mixture to get into the gearbox is by the crank seal on the clutch side and the main engine gasket (or a defect housing, but that surely doesn´t happen too often).

If the crank oil seal on the clutch side is ok, it will be the main gasket. If it was fit with some silicone or similar gasket like Dirko, Curil and so on, it is easy possible for the gasket to run out

of it´s suggested place. The fluid gasket pushes the paper gasket out of its proper position, mostly if the fluid gasket is applied too thick.

You can repair that without removing the whole engine. Just take of the outer (ignition) side and watch closely. Normally you will see, if the papergasket sat on the wrong place.

As I see, you already separated the engine. Did you take a closer look at the main gasket?

 

I don´t know much about the T5 carburator, but are you sure you fit in the correct needle? Your second problem seems to come from that direction. There are different sizes, i.e. for Cosa and PX - maybe also for T5.

Remove the top with the needle and "floater", open the fastflow tap (which surely isn´t the problem) and push the "floater" gently upwards with your finger. It needs to close completely with very less of force. If it drips or something like that, you know where the problem is.

A much more proper way to check the needle valve is surely by just posing it on a glass. If the glass fills up to the upper line, the valve has to close automatically.

If the crankcase was full of fuel, and you kicked it, there was VERY much pressure in the crankcase. Maybe even a good looking oilseal couldn´t hold that. But the maingasket surely is moreoften the "devil" in this case...

 

Sorry for my english, i hope you got what i mean.

Good Luck!

[Stein]

Thank you very much sammba for taking the time to reply to me!!

 

 

I will take a closer look at the casings just to be sure there are no cracks.

 

Also I did not use any extra sealant, only the paper gasket, but it might have been a too thin version, and also what you write about gasket out of possition makes sense. I will check further.

 

I will also check the float needle in the ways you suggest.

 

Thanks again,

 

Stein

[gatti500]

ballontest !

[Stein]

ballontest !

 

Und wie macht man ein ballontest?

[zimbo]

Ballon an die Motorentlüftung.....

[Stein]

Ballon an die Motorentlüftung.....

Aha, habe en such hier im forum gemacht und habe alles klar was zu machen.

[tarzan]

Hi Stein!

 

Some Casings have a too thin seal surface in the small half near by where the "Tannenbaum" is sitting. When then also the main Gasket is a little bit pushed away like sammba said...

 

http://www.germanscooterforum.de/topic/167895-px-motoren-die-getriebe%C3%B6l-saugen/page-8#entry1067570356

 

Maybe that together with a not closing carburator.

 

Greets from Hamburg

Bearbeitet 29. Juli 2014 von tarzan

[Truls221]

Hi Stein!

 

with the amount of 1,5 liters it is not likely that it is coming through a leaking seal or a small leak in the gasket! Sorry but I don't Believe it!

 

1,5 liters takes some time to fill up.

 

Could it come either from the vent hole in the clutch cover or perhaps from the hole where the oilpump shaft was sitting?

 

if you had such amounts of fuel in the crankcase and tried to kick it, you would not be able to kick the Engine around, and not to start it.

 

even if the fuel came into the crankcase and was leaking to the gearbox the Engine would not run if it was that wet!

 

my first pressure tested Engine was leaking from the crankcase to the gearbox. this Engine ran fine, had more than 35 ps and

just a slight hang on the throttle would assume it was having false air as well as a Little White smoke from the exhaust at full throttle. other than that no fuel in the oil or smell of fuel in the gearbox.

when pressure testing, the pressure of 0,5 bar would only hold for 10 seconds

 

my Point is, 1,5 liters is too much. it has to come directly from the tank or carb.

if you drove 10 tanks and the Engine had no idle at all perhaps I would suspect the seal but not else.

 

also I would throw that fuel tap and use either BGM or standard.

 

good luck Stein, hope you solve it!

 

cheers

 

Truls

[sammba]

Sounds logical,

but I just bought a px this year with the same Problem.

It just ran several times around the Block - no more oil left in the gearbox, instead of that more than a litre of Fuel.

There it was the main Gasket.

But you could be right, if the needle valve leaked and the whole carburator case stood full of fuel, additionally the oil Pump Holes weren´t sealed right

this could be an option.

Should be checkable by just evaluating if there was still gearbox oil (and fuel) in the gearbox...

In my case only fuel was left - the cleanest engine (from the inside) i ever had

[Truls221]

Sounds logical,

but I just bought a px this year with the same Problem.

It just ran several times around the Block - no more oil left in the gearbox, instead of that more than a litre of Fuel.

There it was the main Gasket.

But you could be right, if the needle valve leaked and the whole carburator case stood full of fuel, additionally the oil Pump Holes weren´t sealed right

this could be an option.

Should be checkable by just evaluating if there was still gearbox oil (and fuel) in the gearbox...

In my case only fuel was left - the cleanest engine (from the inside) i ever had

Perhaps that could be... but my Point is a major leak like that you will notice on the Engine running...

 

a very good thing I have used with flooding carbs came on my mind.......

 

http://www.zipnorth.com/index.php?main_page=product_info&products_id=706

 

cheers

 

Truls

[sammba]

How the heck does that work?

[Stein]

Ok guys, thanks for all the feedback and suggestions!

 

I will put on the original fuel tap, never had a good feeling about the SIP one anyway (have driven thousands of kms for more than 10 years on my 28 hp 210 with standard fuel tap, so should be good enough With a standard one on a mildly tuned T5 too).

 

Will search casings for cracks, check my closing of the premix hole, check the seal surfaces and do a test on the carb needle.

 

I am glad the scoot didnt turn into a burning inferno since I actually drowe it minutes prior to finding all the fuel in the gearbox, and yes, cleanest casings I have ever seen.