bobcat 610 carb pouring raw fuel out intake side

[Yzracer239]

Ive got a 610 which I bought last year and though it was only a very short moment when limping it off the trailer, I know it ran, and seemed pretty well too. Fixed a bunch of mechanical stuff needed, now back to getting it running so I can use it. Im having trouble getting it to start and stay running...but mostly start. Other than a few seconds, some with ether, some without, I cant seem to get it to fire and stay running. I have the air cleaner assembly off, so open carb. When I crank it for a few seconds then stop. Raw fuel dumps out the intake side of the carb. Behind the mechanical fuel pump on the block, there is a petcock looking lever device. What is that? right now the little lever on it is in the vertical position. I have 4 new sparkplugs, checked for spark on all cylinders, and checked compression. It has 90, 100, 110, and 110 psi. I had the carb off last week, took completely apart, polished all brass, bead blasted the body, and returned all screws to same position(assuming they were right, though I know it ran), and made new cork gaskets. I was a slightly unsure making the gasket for the two carb halves, as the one on it was also home made, but poorly made. There was a certain portion I was unsure to leave gasket material in place or not, though I cut it out, as it seemed to make more sense. Seemed to be some kind of passage, though I dont see that being my issue. Maybe it is and I should order and oem gasket. Any help why my carb is dumping fuel and what is the lever behind the petcock.

 

[Yzracer239]

Something I also want to add is, when I bought the machine, it had a dead fuel pump and a gravity fed fuel tank. I replaced the pump but never really ran the machine with it. I read something about those sometimes having too strong of a spring and flooding carb. If thats it how do I go about finding the new spring?

 

[Tazza]

Something I also want to add is, when I bought the machine, it had a dead fuel pump and a gravity fed fuel tank. I replaced the pump but never really ran the machine with it. I read something about those sometimes having too strong of a spring and flooding carb. If thats it how do I go about finding the new spring?

You have made a good start, that's what i'd do too.
Does it have a float? i wonder if that could be set wrong, allowing it to over fill and dump fuel into the cylinders.
As for the screws, i had in my head that the setting that *should* get pretty well all carb engines running is all the way in then out 1 1/2 turns as a starting point. Then you tweak it from there, it may help you get it going.

 

[mark18mwm]

The fuel running out of the carb is almost assuredly a stuck / sunk float or bad needle valve. First lightly tap on it, that might jar it loose and it might work correctly. If that don't do anything you have to take it back apart to see why the valve is open Usually one of three things, float has filled with fuel and sunk in the gas letting gas keep running. to see if it sunk take the float off and shake it to see if you feel or hear gas in it, it should be empty. there might be a piece of debris between the needle and seat letting gas run and overflow the carb. If that don't seem to be the problem change the needle and seat, they are relatively cheap, they can go bad and not stop the gas from running. You said you made a new cork gasket, did you make it for between the top and bottom halves of the carb? those should be paper gaskets, a home made gasket might be touching the float not allowing it to move. Did you check the float height when you had it apart? It should sit leval when the top half is held upside down. I suspect the home made gasket might be the trouble but you should look at all these things to make sure. As for the petcock on the carb, that is to drain water out of the carb should any get in it. If I was you, I think I would get a carb kit and go through the carb with oem parts, then you know what you have. The carb kit will have all the gaskets and a new needle and seat.

 

[mark18mwm]

The fuel running out of the carb is almost assuredly a stuck / sunk float or bad needle valve. First lightly tap on it, that might jar it loose and it might work correctly. If that don't do anything you have to take it back apart to see why the valve is open Usually one of three things, float has filled with fuel and sunk in the gas letting gas keep running. to see if it sunk take the float off and shake it to see if you feel or hear gas in it, it should be empty. there might be a piece of debris between the needle and seat letting gas run and overflow the carb. If that don't seem to be the problem change the needle and seat, they are relatively cheap, they can go bad and not stop the gas from running. You said you made a new cork gasket, did you make it for between the top and bottom halves of the carb? those should be paper gaskets, a home made gasket might be touching the float not allowing it to move. Did you check the float height when you had it apart? It should sit leval when the top half is held upside down. I suspect the home made gasket might be the trouble but you should look at all these things to make sure. As for the petcock on the carb, that is to drain water out of the carb should any get in it. If I was you, I think I would get a carb kit and go through the carb with oem parts, then you know what you have. The carb kit will have all the gaskets and a new needle and seat.

tazza is right about the adjusting screw go all the was in until it lightly seats and back it out 1 1/2 turn. If the spring on it is what you are talking about, don't worry about it. It is there to keep the screw from backing out due to vibrations.

 

[Yzracer239]

The fuel running out of the carb is almost assuredly a stuck / sunk float or bad needle valve. First lightly tap on it, that might jar it loose and it might work correctly. If that don't do anything you have to take it back apart to see why the valve is open Usually one of three things, float has filled with fuel and sunk in the gas letting gas keep running. to see if it sunk take the float off and shake it to see if you feel or hear gas in it, it should be empty. there might be a piece of debris between the needle and seat letting gas run and overflow the carb. If that don't seem to be the problem change the needle and seat, they are relatively cheap, they can go bad and not stop the gas from running. You said you made a new cork gasket, did you make it for between the top and bottom halves of the carb? those should be paper gaskets, a home made gasket might be touching the float not allowing it to move. Did you check the float height when you had it apart? It should sit leval when the top half is held upside down. I suspect the home made gasket might be the trouble but you should look at all these things to make sure. As for the petcock on the carb, that is to drain water out of the carb should any get in it. If I was you, I think I would get a carb kit and go through the carb with oem parts, then you know what you have. The carb kit will have all the gaskets and a new needle and seat.

Yes it has a float, but it worked before and I was sure not to bend it, and be sure no debris got in the needle and seat before re-assembly. Even if the float height was wrong, shouldnt there be an overflow tube (can't remember there being one or not) to pour out, not the intake! As for the petcock, im not talking about the float bowl drain, this is entirely separate from the carb. Its a lever located on the fuel pump housing on the block.

 

[Yzracer239]

Yes it has a float, but it worked before and I was sure not to bend it, and be sure no debris got in the needle and seat before re-assembly. Even if the float height was wrong, shouldnt there be an overflow tube (can't remember there being one or not) to pour out, not the intake! As for the petcock, im not talking about the float bowl drain, this is entirely separate from the carb. Its a lever located on the fuel pump housing on the block.

As tazza also said, about float height being wrong and dumping fuel intake cylinders. Its not even making it there. The second you stop cranking it sloshes out the intake side of the CARB, as I have the air cleaner assembly off

 

[6brnorma]

As tazza also said, about float height being wrong and dumping fuel intake cylinders. Its not even making it there. The second you stop cranking it sloshes out the intake side of the CARB, as I have the air cleaner assembly off

The lever is a primer.

 

[Unicam]

As tazza also said, about float height being wrong and dumping fuel intake cylinders. Its not even making it there. The second you stop cranking it sloshes out the intake side of the CARB, as I have the air cleaner assembly off

mine wants to flood super easy. being an updraft carb gas will run out the inlet (lowest point). i think the crank case vent is low too, i'd have to look but you don't want gas going in there. make sure your choke is functioning properly too, also make sure the internal venting is clear, it needs to breath to function properly. I have a gallon of chem-dip from walmart i soak carbs in.

 

[upnorth4951]

The lever behind the fuel pump is a optional primer pump on some engines. Takes 20 pumps to prime the pump never used mine as it pumps great. You should have 2-3 psi fuel pressure more than that will cause flooding. Book says after a while the spring in the pump can become weak and the pressure will actually increase and is fixed easily with a pump kit. Problem is that the kits don't seem to be available any more. It doesn't take much debris to stick the needle open either so a small micron fuel filter may help also. Remember if gas gets really deep in that vent neck it goes straight to the crankcase and would need to drop the oil again and again. I thought about venting that fuel to the ground when flooding occurs and vent the case separately but haven't done so yet. Hope this helps.