[Mjolinor]

Well one would assume that when things returned to normal it would go back up again to a correct level. Is it also reasonable to assume that if it did then that may have been mentioned?

I just assumed it went down and stayed down.

 

[C-130 jumper]

I don't believe the oversized jets are the cause for excessive fuel in the crankcase. I suspect the carb float valves are not sealing. By what other method does that much fuel get into the crankcase? Fuel must be running out the carbs down through the intake valves, into the cylinders, past the rings and into the crankcase. Notice the angle the carbs are mounted at, poor float valves let fuel just overflow into the intakes.

Try lowering float levels like he suggested may be the problem. If you need jets this is the source I use:

Carburetor jets, parts and tuning items - Jets R Us

www.jetsrus.com

 

[WFO-KZ]

It's a simple application of the laws of physics. Under full throttle anything not nailed down will move with the G-force.
The fuel won't slosh until the throttle is backed off.

This is easier to explain with G-forces of braking. If you slam on your car brakes at high speed, you will be thrown forward against your seatbelt and you will remain firmly against the seat belt until the G-force reduces.

A physics teacher could explain it better probably.

 

[Mjolinor]

Inertia, not gravity.

 

[WFO-KZ]

Well one would assume that when things returned to normal it would go back up again to a correct level. Is it also reasonable to assume that if it did then that may have been mentioned?

I just assumed it went down and stayed down.

Good point, but I can tell you one thing. At full throttle on a bike with over 100 HP I can ill afford more than a momentary glance at any gauges, so I would not rely on the accuracy of being able to tell if the needle returned to the exact same spot or stayed low. Surely the OP is not telling us that the needle moved by some huge amount like 1/2".

The common sense moment is trying to figure out how it would even be possible for carbs to feed so much fuel into the engine so that one could watch a fuel gauge going down in mere seconds. IMHO it would not be possible for that engine to accept so huge a volume of fuel and still stay running. I think it would be a stream of raw gas, that would likely hydro-lock the engine, or it would be impossible to ignite.

But it's an interesting debate.

 

[WFO-KZ]

Inertia, not gravity.

Hmmm. Interesting. I think you are right, it is inertia of the gasoline that causes it to stay put, but it is the G-force of acceleration of the bike that then pushes the fuel tank against the fuel, deforming the fuel. The end result is the fuel will end up at the back of the tank.

If there were no G-Force of acceleration, the fuel would stay level.

 

[Mjolinor]

Well I know that a bike with two cylinders running on one if abysmal but it is over 40 years since I thrashed a 4 cylinder so have no idea how it would feel on three. Certainly if the rings are buggered on one cylinder it can put an enormous amount of petrol into the oil but would it be obvious if you were not familiar with that type of bike?

 

[WFO-KZ]

With all due respect, several of us... (me included) have taken this in a direction that is not overly helpful to the OP.
We are now speculating, when what we really need is more input from the OP. Let's get this thread back on track please and wait for more input and questions from the OP.

 

[Mjolinor]

No one has mentioned it yet unless I missed it but a compression test would be a good test to do once the plugs are out.

I would also mention that running it is not a good idea as it will wear the engine out double quick if the fuel is washing the bores.

 

[WFO-KZ]

A compression test is a good idea along with the other suggestions made in this thread such as removing the spark plugs to see if they are wet, and testing of the float valve. But we have yet to hear back on the results of any of this advice from the OP.

 

[C-130 jumper]

A compression test is a good idea along with the other suggestions made in this thread such as removing the spark plugs to see if they are wet, and testing of the float valve. But we have yet to hear back on the results of any of this advice from the OP.

First time register with a mechanical problem is usually like this. They want a free diagnosis not tips on troubleshooting.

 

[DerEnstafferrrr]

The fact that someone is asking for help does not mean they want a free diagnosis.
I was running out of ideas, but a few suggestions in this thread were really helpful, as I did indeed find the problem.
Not everyone has dozens of years of experience, and asking for ideas is not asking for a free diagnosis.
Thanks to everyone who made a serious effort to help and keep this thread on track, and @C-130, while helpful at first, your last comment really made you look like a bigheaded idiot. Feel free to ban me if you need to do so, in this case I will not apologize.

 

[C-130 jumper]

The fact that someone is asking for help does not mean they want a free diagnosis.
I was running out of ideas, but a few suggestions in this thread were really helpful, as I did indeed find the problem.
Not everyone has dozens of years of experience, and asking for ideas is not asking for a free diagnosis.
Thanks to everyone who made a serious effort to help and keep this thread on track, and @C-130, while helpful at first, your last comment really made you look like a bigheaded idiot. Feel free to ban me if you need to do so, in this case I will not apologize.

Frankly dgaf lol

 

[Mjolinor]

And the problem was?

 

[Mjolinor]

Not looking like we are going to find out.

It is the worst thing about Internet forums is that. You invest yourself in the problem and are left hanging for eternity.