BOBCAT 642 GAS 1.6lt ford gas flooding the old carb and the new carb

[BOB624GAS]

Been here a few times because google sent me, read plenty and felt it was time to join.

That said I need some help understanding why my machine was running fine for a month and then seemed to flood out never to start again for the last couple weeks, and with winter coming I need her to come home.

What happens is that when I turn key to (on) position the carb fills and wont stop filling. I watched gas flow freely out the overflow, backup into intake tube, and if engaged to start has made its way out the exhaust manifold.

Drained oil, and there was lots of fuel in the oil.

Refilled with oil, swapped for a new carb (old one looked fine)

With the fuel pump disconnected I checked for spark it was good, so then we sprayed quickstart into the intake tried starting. Loooong turns of the ignition gave the odd coughs to try and start but very far and few between.
)
Connected a new 1.25-3psi 12v fuel pump (the old one was 3-5psi) and turned to the on position, again fuel just dumped out the new carb just like the old one did which remember it looked fine once we had it off.

So why do you guys think the fuel keeps overflowing the bowl/needle/seat, why suddenly after days of work did she start to lose power and "dog out" to the point I was like crap I should park it for the day with the bucket up just in case.

Before this I already changed the coil with a flame thrower pertronix, new coil, fuel lines, cleaned the fuel tank, filter new, and the 3-5psi pump.

Thanks in advance!

 

[BOB624GAS]

 

[BOB624GAS]

 

[ZekeSkyree]

My thought is an issue with the needle and seat. I'd get a rebuild kit and thoroughly clean/rebuild the carb. It's an easy one to rebuild.

It also could be that the fuel shut off solenoid on the carb is stuck open, which, if there is a problem with the needle/seat would allow a large amount of gas to freely flow into the engine oil, or even the cylinder head and hydro lock the engine .... Ask me how I know.

I hope this helps...

 

[BOB624GAS]

I swapped out the old carb and it was actually ok, but still I put a new one in same thing!
This fuel shutoff solenoid can it be bypassed for a test? Location?

 

[Sapientoni]

For sure the float and seat of the fuel bowl are the problem. If the float is a cork or phenolym type, it will absorb the methanol from the new fuels and then sink or fail to properly operate. I have dried this type float out in the past and tried sealing it with POR-15 sealant. It needs to be as thin a coat as you can brush onto it, but get full coverage. Then reset the level. In the rare case a brass float was available, that would be the best option. I have adapted a Briggs and Stratton brass float to an S & S carb on an old Harley and it worked great. NAPA had LOTS of engineering drawings on their website of the parts you could buy and the Briggs Float was pretty close. I had to fabricate the bracket for the needle adapt. It might take some looking to see if you could do that. I don't know how much trouble it would be to adapt a TBI from something like a Geo Tracker, but that might be something to consider if the simpler things don't fix it. Good luck and let us know what you find out and do.

 

[BOB624GAS]

So I opened the old carb up and when I blow thru the fuel inlet it works as it should. As I lift the float it closes. This is a brass float and seems to be sealed to me.
Also remember I put a new carb on

But your saying it coincidentally was able to absorb or leak in methanol within less than 10secs of me turning key to on position and my old brass floats are NG.

I don’t say the above like a dik I’m just challenging you a bit. I mean in a way I want you to be right but two floats same thing?

I’m unsure what the floats are in the new one as I didn’t open it. Crap who knows maybe the new one didn’t even come with floats pre installed?!

I’ll attach a video of the old one because it’s here now.

 

[BOB624GAS]

My thought is an issue with the needle and seat. I'd get a rebuild kit and thoroughly clean/rebuild the carb. It's an easy one to rebuild.

It also could be that the fuel shut off solenoid on the carb is stuck open, which, if there is a problem with the needle/seat would allow a large amount of gas to freely flow into the engine oil, or even the cylinder head and hydro lock the engine .... Ask me how I know.

I hope this helps...

So I located the fuel solenoid but did not test its operation

 

[ZekeSkyree]

To test the solenoid, just apply 12v to it and see if the needle retracts. Also, there is another fuel shutoff you can check. Looking at the engine compartment it's on the upper right side and has wires going to it. It is normally closed so applying voltage will open it. Let me know if you want a picture ..

 

[Sapientoni]

So I opened the old carb up and when I blow thru the fuel inlet it works as it should. As I lift the float it closes. This is a brass float and seems to be sealed to me.
Also remember I put a new carb on

But your saying it coincidentally was able to absorb or leak in methanol within less than 10secs of me turning key to on position and my old brass floats are NG.

I don’t say the above like a dik I’m just challenging you a bit. I mean in a way I want you to be right but two floats same thing?

I’m unsure what the floats are in the new one as I didn’t open it. Crap who knows maybe the new one didn’t even come with floats pre installed?!

I’ll attach a video of the old one because it’s here now.

Yes, your issue is a puzzle. Perhaps there's an engine vibration that's overpowering the float? For certain I've never seen a carb that didn't have a float and needle to control the gas level. The constant flow points to needle not seating correctly for some reason. The possibilities are limited, obstruction, over pressure, damaged seat or needle, float obstruction.
Absolutely keep the brass float in there.
Good luck and let us know what corrects the issue.

 

[BOB624GAS]

So we eliminated the fuel pump, and went with gravity feed and a ball primer that stopped the flow of gas out the carb.

Inside the distributor cap the rotor was loose, a wire was fried, and the contacts closed.

Adjusted and she fired immediately. Gave it throttle while cold and she died (impatient I was)

Now there’s no spark again, so clearly we need to go I. The cap again.

Before I go in again I bought this kit and a new cap

 

[ZekeSkyree]

Just a thought. I got tired of points & condenser a few years back and swapped for this kit. Been solid as a rock and half the cost of the Pertronix kit.

https://simonbbc.com/Powerspark-Electronic-Ignition-Kit-for-Motorcraft-4-Cyl-Distributor-K12

 

[BOB624GAS]

I had already bought the pertronix, was not the right one.

For fear of making another mistake and delaying farther in to the freeze weather I opted for the kit listed above.

Your right imo and wish I had seen this sooner

 

[BOB624GAS]

ok so heres the update, I installed the cap, points, rotor, plugs and condensor. The 3gpm 12v fuel pump is removed and I am relying on gravity feed with the primer ball.

She fired and ran well enough for me to get it from down in the location where it was "stuck" and back to the house. I let it run for a while and then shut it down for dark.

Unsure if the gravity feed will be able to supply enough gas but what I do know is that the fuel is NOT running out like it was. Ill be back with more info in a day or so.

HOWEVER my tilt was getting weak before all this happened. Loader lifts and lowers as it should (left pedal control) but the tilt (right pedal control) only goes down and not up. Before it quit on me I would have to really step into it to make it tilt upward. I feel this is linkage, any advice?

 

[foton]

with gravity feed I heard somewhere that for about every 18 inchs of height you can get about 1 psi of pressure,that was most likely water not gas, but maybe close enough to make a guess.

 

[brdgbldr]

Your weak tilt is probably a bad piston seal in he tilt cylinder.

 

[BOB624GAS]

so the tilt turned out to be and old rag under the pedal, and the linkage way out of whack.

And the fuel gravity feed don’t work. Prime it and she runs strong. After awhile she plays games I feather the choke and keep it going but eventually that just don’t really work until I get out and go to the motor and prime again, repeat. Will reconnect the 3psi fuel pump as it always had and assume that’s gonna work ?!

BUT

Now the exhaust manifold is getting cherry red, and I don’t know how to confirm if it’s cooling?

 

[foton]

the red exaust manifold might be your timing is out of spec.

 

[shankatank58]

From the other issues he’s discribing probably running much too lean. Check the plugs

 

[spitzair]

Sounds like a timing issue to me if the exhaust is getting red hot. I'll have a look in my manual later today and post the timing procedure for you so you can verify that.