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Old 08-23-2011, 01:16 PM   #21
tcrave
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Re: Crankcase filled with fuel...help!!

Quote:
Originally Posted by Gz Rider
Quote:
Originally Posted by tcrave
I'm guessing the fuel got into the crankcase because my buddy tapped on the float and unstuck it. He thought he was fixing it, but I think that just made it worse. I read somewhere in my research that these bikes have a safety mechanism in the carb that when the petcock fails, the float gets stuck and lets the fuel go out the drain pipe instead of into the crankcase. I also noticed that before he did that, the oil window looked fine, then after he did, thats when it looked bad. Lesson learned though.
I'm not sure of exactly what happend when but I don't think tapping of the float caused any part of your problem.

As I understand it the system works something like this:

Fuel sits in your fuel tank and is held back by a vavle in the petcock. The engine provides vacuum to the petcock via a small tube in the back if the petcock. This vacuum opens the vavle while the engine is turning or cracking and the fule runs into the carb bowl.

The fuel raises the float in the bowl until the float rises so high that is causes a vavle/needle to shut off the flow of gas. The carb has lots of little holes/jets that then stuck the gas out of the bowl and into the intake for combustion. The float drops from lack of gas and the vavle/needle opens again allowing more gas into the bowl.

In your case it seems like two things had to have happened. First, your petcock seems to have failed because you describle fuel flow without the engine turning. That shouldn't happen.

Second, even if fuel does flow when it shouldn't, the float in the bowl should cat off the flow prior to overflowing the bowl. Tapping on the bowl could cause the malfunctioning vavle/needle to reseat itself and cut off the fuel and that would be a good thing. I can't see any harm comming from tapping the bowl.

All I see happening is that the two items failed (probably one failed quite a while ago) allowing your float bowl to overflow and once it did that the gas flowed into the cylinder and then into the crackcase. With the crackcase filled with oil and gas the cylinder was hydrolocked.

I have to say I was very impresses with Blaine's diagnosis given the description (no offense to you). It sounded to me at first read like you bike had become possessed by the devil!

Now go apologize to your buddy for ever having doubted him.
Ahhh...I actually have an idea now that you mentioned the vacuum valve. I was wondering what that was, I thought it might have been a vacuum, but wasn't sure. I took the petcock off and took it apart and everything in there looks fine. I saw some dirt on the filters attached to the tubes, but nothing beyond that. All the gaskets seemed fine and everything. I looked at the petcocks channels and realized there is nothing in the petcock to hold the fuel back...so I was wondering what the hell holds the fuel back, then I saw that tube. I am wondering if maybe the vacuum pressure in the tube actually holds the fuel and PREVENTS it from coming out and going into the carb?? Then onces the engine is running maybe the pressure stops and lets the fuel run?

I really did not see a single thing in the petcock that would stop the flow of fuel...that kinda scares me...well, I take that back, there was a little disc with a spring loaded...maybe that has something to do with it...but it looked fine to me, so I don't know how that could have failed.

I am wondering that maybe if my theory is correct, maybe the vacuum hose got disconnected and didn't provide the suction needed to prevent the fuel from flowing? Or maybe the vacuum fell off in the open position?

So it hydrolocked bad? Is it repairable?

Yes, I agree, blaine did a great job, so did you.

Well, I never accused him of doing anything wrong, that was just a theory I kept to myself. He is a diesel mechanic and knows just about everything there is to know about gasoline engines as well...and so does his dad, and both of them where there. He suggested to me not to mess with the carb and just to drain the crankcase out, put fresh new oil in it and a new oil filter, change the spark plug, and go from there. (provided that I had already drained the airbox.) I really would like to clean the carb, but at the same time, I don't want to do more damage that I need to. I have never taken a carb apart before so I only have a slight idea of what I am getting myself in to.

Thanks for you help!!



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Old 08-23-2011, 01:19 PM   #22
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Re: Crankcase filled with fuel...help!!

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I am wondering what was the exact reason for transporting the bike on it's side rather than upright. You stated it was the wrong kind of trailer so what was the issue with the trailer ??
It was just a flat trailer, no sides or anything. They didn't have much notice or idea on what was going on either, they both figured we could get it start up, so they only brought like 3 straps. Since we didn't have any sides to wedge the bike against, we didn't want to take a chance of it falling over or rolling or anything and we just laid it down for transport. Put a spare tire under it to protect the turn signals and blankets to protect the paint.
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Old 08-23-2011, 08:17 PM   #23
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Re: Crankcase filled with fuel...help!!

Quote:
Originally Posted by tcrave
I am wondering if maybe the vacuum pressure in the tube actually holds the fuel and PREVENTS it from coming out and going into the carb?? Then onces the engine is running maybe the pressure stops and lets the fuel run?

I really did not see a single thing in the petcock that would stop the flow of fuel...that kinda scares me...well, I take that back, there was a little disc with a spring loaded...maybe that has something to do with it...but it looked fine to me, so I don't know how that could have failed.

I am wondering that maybe if my theory is correct, maybe the vacuum hose got disconnected and didn't provide the suction needed to prevent the fuel from flowing? Or maybe the vacuum fell off in the open position?

So it hydrolocked bad? Is it repairable?
The petcock works exactly the opposite.It needs the vacuum for the petcock to open and the fuel to flow.That way when the engine is not running,the petcock is closed.The hydro lock will be eliminated when you drain the old oil & change the plug.
:cool:
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Old 08-24-2011, 12:11 AM   #24
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Re: Crankcase filled with fuel...help!!

We need suggestions for getting rid of any fluids that may be in the cylinder. Maybe spinning the motor over with the starter and the spark plug out.
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Old 08-24-2011, 01:16 AM   #25
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Re: Crankcase filled with fuel...help!!

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We need suggestions for getting rid of any fluids that may be in the cylinder. Maybe spinning the motor over with the starter and the spark plug out.
Yes agreed.I should have stated that! :plus1:
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Old 08-25-2011, 01:58 PM   #26
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Re: Crankcase filled with fuel...help!!

Quote:
Originally Posted by blaine
Quote:
Originally Posted by tcrave
I am wondering if maybe the vacuum pressure in the tube actually holds the fuel and PREVENTS it from coming out and going into the carb?? Then onces the engine is running maybe the pressure stops and lets the fuel run?

I really did not see a single thing in the petcock that would stop the flow of fuel...that kinda scares me...well, I take that back, there was a little disc with a spring loaded...maybe that has something to do with it...but it looked fine to me, so I don't know how that could have failed.

I am wondering that maybe if my theory is correct, maybe the vacuum hose got disconnected and didn't provide the suction needed to prevent the fuel from flowing? Or maybe the vacuum fell off in the open position?

So it hydrolocked bad? Is it repairable?
The petcock works exactly the opposite.It needs the vacuum for the petcock to open and the fuel to flow.That way when the engine is not running,the petcock is closed.The hydro lock will be eliminated when you drain the old oil & change the plug.
:cool:
Hmm...that scares me because when I was draining the fuel from the tank, there was no way to stop it from coming out....as in even when it was in the "on" position, it still kept flowing out. When I took apart the petcock, everything looked fine from what I could tell...didn't see any broken or worn parts. Maybe I can take some pictures and see what you think.

Good deal on eliminating the hydro lock, thanks!
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Old 08-25-2011, 02:00 PM   #27
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Re: Crankcase filled with fuel...help!!

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Originally Posted by Water Warrior
We need suggestions for getting rid of any fluids that may be in the cylinder. Maybe spinning the motor over with the starter and the spark plug out.
Good point! I am really glad you brought that up! Thanks for saving me $50 and a huge headache!
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Old 08-25-2011, 02:11 PM   #28
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Re: Crankcase filled with fuel...help!!

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Originally Posted by Gz Rider


I think Blaine answered your question with regard to the petcock.

Hydrolock as I used it was an attempt to show what was happening inside of your engine. Almost everything in your engine had fluid of some sort in it. The fluid was oil, oil mixed with gas and straight gas. The fluid flowed down from your intake valves, I believe and filled up the engine below. That means the crankcase is full, the cylinder is full and even that space above the piston is full of fluid.

If the piston tries to move downward it would have to displace fluid below the piston. Some fluid could pass from the crankcase to the space above the piston by running through the piston rings but that space is small. You would also need more pressure on the piston to do this than your starter can provide.

If the piston tries to move up, then suction would be created below the piston preventing it from moving and if it did move, the fluid on top of the piston would tend to be ejected either out the exhaust valves (that could be a mess in the muffler) or out the intake valves (which is what I believe happend based on your description of squirting fluids). You might want to pop off the muffler and check it(not a hard job but if the exhaust bolts are seized from heat (normalish) you could have difficulties.

The point is the engine would not move with fluid all around it. Hydrolock is a good thing for you in this case as you would not want the engine to rotate in this condition anyway. The only part of you bike that should have suffered should have been the poor starter trying to turn that engine. I'm sure your starter is no worse for the wear though.

So, drain the engine and hydrolock is cured. Give it at least a half hour of drain time. More wouldn't hurt. I would drain it, get it running and then change the oil again as that would help wash out any hidden pockets of gas. You think your OCD??

I disagree with not cleaning (disassembling) the carb because the carb has shown a fault. I understand the thinking of fix one thing at a time but if you fill the bike with gas and that float bowl valve stick again, the float bowl would overflow again. If you want to follow his advice, the I suggest a minimum amount of gas should be put in the tank (The petcock would have to be in reserve for this) and you should do just enough to get the bike running to your satisfaction then clean the carb and change the oil (if the float valve leaks, there may be a little gas in your oil again).

I could also see getting the bike running and running the carb cleaners (seafoam) through it that many on this board use. I've never had need for them but seafoam seems to have cured a world of ills for carbs. A cleaner could easily fix the sticking float valve. Still change to oil when the carb issue is fixed regardless of how you do it.
[/quote]
Thanks a bunch!! I will get back to answering this after work!
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Old 08-25-2011, 03:03 PM   #29
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Re: Crankcase filled with fuel...help!!

Quote:
Originally Posted by tcrave
Quote:
Originally Posted by Water Warrior
We need suggestions for getting rid of any fluids that may be in the cylinder. Maybe spinning the motor over with the starter and the spark plug out.
Good point! I am really glad you brought that up! Thanks for saving me $50 and a huge headache!
Fluids in the combustion chamber don't compress like an air/fuel mixture. Major damage can result in some cases. A bent connecting rod is not uncommon.
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Old 08-26-2011, 09:07 AM   #30
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Re: Crankcase filled with fuel...help!!

Yeah. If you have to be totally certain, there is nothing wrong with pulling the plug and looking. Heck, shoot some compressed air in there and see if you blow some fluids around.

I'll be the liquids drained past the rings and you have nothing to worry about. You're not the only person to ever have a flooded engine.
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