732 altenately stalls then floods

[LazyKG]

I've been reading these forums for about a month and can see we've got some very knowledgeable folks. I find myself needing help with the new-to-me 732. It alternately acts like it's not getting fuel only to flood sometimes when left off. Here's the story which started before I bought it. --- Go to look at it, won’t start. Put in gas, starts and runs fine. Go back to get it, won’t start. Seller replaces fuel pump, won’t start. Bobcat mechanic cleans carb, found a “piece of dirt”, starts and runs fine. I load it up, stopping and restarting several times, no problem. Get home, won’t start. Find carb solenoid rewired wrong – only connected to “ON” key position not “START” position. Starts and runs great. Use several times with no issue. --- One day, run it 5 minutes and shut it off for 15 minutes. While off, carb floods big time, had to take breather hose off to drain gas. Let it dry out and it starts and runs fine. Runs fine the next few ties it’s used. --- One day, runs fine for 20-30 minutes. Shut off for a bit and try to start, won’t start. I check for spark which is ok. While it’s off, carb floods big time. Pull breather hose and let it dry. Starts up fine and runs for another 10-15 minutes and shut it off for 10 minutes. Floods again while off. Dry it out and start it up again, runs fine for the rest of the day, several more short runs, 15 – 30 minutes each, no problems. --- Another day, starts up fine runs for 10 – 15 minutes then stalls in the pasture and will not run. Starts, runs for a second or two then stalls. Numerous starting attempts all end the same way. Let it sit overnight. Next day, remove carb and give it a look over and shake it up thinking the float or needle is stuck. Put it back on, no change – start, run for a second or two, stall. Numerous tries, same thing. Take the carb off and open it up giving it a quick rinse in gas (no cleaner handy). Put it back on and no change. Let it sit overnight. --- Next day, it’s flooded again big time. Shut off gas supply, remove carb, get cleaner and gasket material. Give it half-a**ed cleaning - no parts were removed out of fear of breaking something without a carb kit for replacements. Replace it, no change – start, run for a second or two, stall. Turn off gas, let it sit overnight. --- Next day, I adjust the idle valve to see of maybe something as still stuck there. No change. That afternoon, I go to test the fuel pump since I know gas if flowing but maybe not fast enough to keep It running. I crank it with gas off to clear fuel from the lines and car and the dang thing starts and continues to run! WTF? It runs rough and stalls if I try to increase speed too much (adjustment to idle valve, I assume). I drive it slowly back to the shed, restarts without trouble when it stalled on the way and restarts and runs after I parked it. --- I shut it off to mow the yard and when I get back a couple hours later it’s flooded again big time. I shut off the gas and dry it out. I’ll leave it sit until the carb kit arrives. --- Could it be the carb solenoid sticking open or closed? If so, how do I test it? What else might it be? --- Thanks in advance for any assistance.

 

[Tazza]

I was thinking the carb solenoid too. If it's not plugging the hole porperly when off, it will allow fuel to build up. Yet i'd have thought the float would stop too much fuel getting in there.
I'd check both the float valve and the electric solenoid.
If the solenoid is bad, i wonder if you could install an inline solenoid in the fuel line and plug the hole up for the carb solenoid after removing it.

 

[LazyKG]

I was thinking the carb solenoid too. If it's not plugging the hole porperly when off, it will allow fuel to build up. Yet i'd have thought the float would stop too much fuel getting in there.
I'd check both the float valve and the electric solenoid.
If the solenoid is bad, i wonder if you could install an inline solenoid in the fuel line and plug the hole up for the carb solenoid after removing it.

Thanks for the reply, Tazza. I am now convinced that it is the solenoid. It finally occurred to me to test impedence and could not get a reading connecting to the power wire and the carb body. I can get a reading through the carb body itself and through the power wire from the connector to just before that wire enters the solenoid itself. I even tried applying 12v trhough the unit but nothing happens. I did get the carb kit and thorouhly cleaned the carb. After reinstalling, though, it will not start. I can smell gas some in the motor after trying to start it, but it does not appear to be flooding on or off. The local Bobcat dealer can get a replacement solenoid for a little over $200. Hope that works.

 

[jerry]

Thanks for the reply, Tazza. I am now convinced that it is the solenoid. It finally occurred to me to test impedence and could not get a reading connecting to the power wire and the carb body. I can get a reading through the carb body itself and through the power wire from the connector to just before that wire enters the solenoid itself. I even tried applying 12v trhough the unit but nothing happens. I did get the carb kit and thorouhly cleaned the carb. After reinstalling, though, it will not start. I can smell gas some in the motor after trying to start it, but it does not appear to be flooding on or off. The local Bobcat dealer can get a replacement solenoid for a little over $200. Hope that works.

On the 632 I had there was a electrical shutoff solenoid valve on the fuel line as it went across the back cab wall. I would think you have float and needle trouble really, those things will run ok with the solenoid removed from the carb and a plug put in the hole. It is just a anti dieseling device and if the other shut off is working and the needle valve is ,it should not flood. Take the needle out and with fine emery clean the shaft so there is nothing to hold it up.

 

[LazyKG]

On the 632 I had there was a electrical shutoff solenoid valve on the fuel line as it went across the back cab wall. I would think you have float and needle trouble really, those things will run ok with the solenoid removed from the carb and a plug put in the hole. It is just a anti dieseling device and if the other shut off is working and the needle valve is ,it should not flood. Take the needle out and with fine emery clean the shaft so there is nothing to hold it up.

Thanks for the reply, jerry. Mine has the solenoid in the carb, none inline. I did replace the solenoid and it ran like a champ. However, I am still having some sporadic trouble. A couple weeks ago, I'm back and forth - carry blocks to the splitter, split the wood, carry the split wood to the barn, unload, then off for another load of blocks. I'd made three or four such circuits, shutting the engine off at each step, when the darn thing suddenly floods. I shut the fuel off, wait fro it to dry out, then stat it up and park it in the shed. Yesterday, I go to start it and it starts and runs fine. This time, and I'm hauling loads of branches, lings and rotting logs to the burn pile, after three or four trips (NOT turning the motor off at all), it stalls and won't start up. I pour in some gas (may have been out) but it still will not start. It tries to start but acts like it's not getting fuel. I'll blow out the fuel filter today in case there's scum from the tank caught in there (I really should clean that out, too) and see what it does.

 

[LazyKG]

Thanks for the reply, jerry. Mine has the solenoid in the carb, none inline. I did replace the solenoid and it ran like a champ. However, I am still having some sporadic trouble. A couple weeks ago, I'm back and forth - carry blocks to the splitter, split the wood, carry the split wood to the barn, unload, then off for another load of blocks. I'd made three or four such circuits, shutting the engine off at each step, when the darn thing suddenly floods. I shut the fuel off, wait fro it to dry out, then stat it up and park it in the shed. Yesterday, I go to start it and it starts and runs fine. This time, and I'm hauling loads of branches, lings and rotting logs to the burn pile, after three or four trips (NOT turning the motor off at all), it stalls and won't start up. I pour in some gas (may have been out) but it still will not start. It tries to start but acts like it's not getting fuel. I'll blow out the fuel filter today in case there's scum from the tank caught in there (I really should clean that out, too) and see what it does.

Well, I pulled and cleaned the carb and fuel filter, bench tested the new shutoff solenoid to be sure it was working and verified unit power to that solenoid. However, the problem still remains...it just won't start. If I leave the key in the On position for a while, enough gas enters the carb to get it to fire but it will not stay running. So, I think I'll try draining the fuel tank to see of that's just blocked with crud. If no, I wonder if the mechanical fuel pump just doesn't. The pump was replaced just before I bought it so I doubt the unit itself is bad. I think I read in this forum someone saying that the spot on the camshaft that runs the pump could be worn such that there is not enough pump action. Although, it ran just fine until it stalled so that does not seem likely either. Anyone have any other thoughts?

 

[jerry]

Well, I pulled and cleaned the carb and fuel filter, bench tested the new shutoff solenoid to be sure it was working and verified unit power to that solenoid. However, the problem still remains...it just won't start. If I leave the key in the On position for a while, enough gas enters the carb to get it to fire but it will not stay running. So, I think I'll try draining the fuel tank to see of that's just blocked with crud. If no, I wonder if the mechanical fuel pump just doesn't. The pump was replaced just before I bought it so I doubt the unit itself is bad. I think I read in this forum someone saying that the spot on the camshaft that runs the pump could be worn such that there is not enough pump action. Although, it ran just fine until it stalled so that does not seem likely either. Anyone have any other thoughts?

If you have a vacuum gauge most of them can be used to check fuel pump pressure also, it usually is only around 4-5 psi. Otherwise disconnect line at the carb and stick a hose on it to a jug and crank the engine over to see how much flow there really is. Don't rule out strange debris in the tank either, had a tractor with carb trouble and after a lot of money was spent on parts it turned out to be a butterfly that drifted over the tank outlet now and then. You also could put a manual shutoff in the line if it continues to flood when left for a time. And of course check the ignition timing, if it is a ford engine they have a habit of the distributor moving when you think it is tight.

 

[LazyKG]

If you have a vacuum gauge most of them can be used to check fuel pump pressure also, it usually is only around 4-5 psi. Otherwise disconnect line at the carb and stick a hose on it to a jug and crank the engine over to see how much flow there really is. Don't rule out strange debris in the tank either, had a tractor with carb trouble and after a lot of money was spent on parts it turned out to be a butterfly that drifted over the tank outlet now and then. You also could put a manual shutoff in the line if it continues to flood when left for a time. And of course check the ignition timing, if it is a ford engine they have a habit of the distributor moving when you think it is tight.

What a bloody marvelous idea! I don't have a vacuum gauge but I can run a line from a clean gas can. I'll give that a shot this afternoon. And there is a fuel shutoff valve; I've been using that every time I power down just in case. BTW - whereabouts in NE MN? I'm in SE MN, near the dinky town of West Concord. Thanks again for the suggestion.

 

[jerry]

What a bloody marvelous idea! I don't have a vacuum gauge but I can run a line from a clean gas can. I'll give that a shot this afternoon. And there is a fuel shutoff valve; I've been using that every time I power down just in case. BTW - whereabouts in NE MN? I'm in SE MN, near the dinky town of West Concord. Thanks again for the suggestion.

Actually gravity flow from a clean jug should be adequate. There is another thread on here about a 632 with similar trouble that was cured with a electronic ignition kit. You live down there in the banana belt whereas I am 30 miles north of Duluth in the rocks and swamps.

 

[LazyKG]

Actually gravity flow from a clean jug should be adequate. There is another thread on here about a 632 with similar trouble that was cured with a electronic ignition kit. You live down there in the banana belt whereas I am 30 miles north of Duluth in the rocks and swamps.

jerry, your idea was most educational. With a short piece of clear hose and a gas can, I was able to see that flow from the tank to the fuel filter is adequate. I can also see that the fuel pump does not seem to work real well at starter cranking speed. I had the gas can about level with the pump and ran the hose from the can to the fuel filter. Cranking, no fuel would move; but, when the engine would start to fire, the increased engine speed caused the gas to move. However, there's not enough gas in the carb to keep it running long enough for gas to get from the can to the carb. I've put the fuel line back together and am charging the battery for a bit then I'll see if that helps at all. You got some nice country amongst your rocks and swamps; down here, we got...corn.

 

[LazyKG]

jerry, your idea was most educational. With a short piece of clear hose and a gas can, I was able to see that flow from the tank to the fuel filter is adequate. I can also see that the fuel pump does not seem to work real well at starter cranking speed. I had the gas can about level with the pump and ran the hose from the can to the fuel filter. Cranking, no fuel would move; but, when the engine would start to fire, the increased engine speed caused the gas to move. However, there's not enough gas in the carb to keep it running long enough for gas to get from the can to the carb. I've put the fuel line back together and am charging the battery for a bit then I'll see if that helps at all. You got some nice country amongst your rocks and swamps; down here, we got...corn.

Charging the battery had no effect on the cranking speed or anything else, it'll try to start, run for a second or maybe two, then nothing. And that's only if I leave it sit for 15 - 20 seconds between cranks with the key on which seems to load the carb via gravity. I suspect that the pump just ain't doing the job. I was going to take the pump off and found the bolts were a little loose, not sure how, so I tightened them up with no change in operation. Based on how the pump is designed, tightening it up looks like it would just move the lever away from the cam (but then, I'm no mechanic or engineer). Not sure what to do next except maybe try an electric pump. Anyone ever make this switch?

 

[SkidRoe]

Charging the battery had no effect on the cranking speed or anything else, it'll try to start, run for a second or maybe two, then nothing. And that's only if I leave it sit for 15 - 20 seconds between cranks with the key on which seems to load the carb via gravity. I suspect that the pump just ain't doing the job. I was going to take the pump off and found the bolts were a little loose, not sure how, so I tightened them up with no change in operation. Based on how the pump is designed, tightening it up looks like it would just move the lever away from the cam (but then, I'm no mechanic or engineer). Not sure what to do next except maybe try an electric pump. Anyone ever make this switch?

Electric pumps are a popular replacement for the mechanical pump. Just make sure you get one that is designed for a carburetor. They have a much lower output pressure than ones for fuel injected engines. I put one on my machine that has an output of about 2.5 psi, works great. Picked it up at NAPA. HTH- SR

 

[LazyKG]

Electric pumps are a popular replacement for the mechanical pump. Just make sure you get one that is designed for a carburetor. They have a much lower output pressure than ones for fuel injected engines. I put one on my machine that has an output of about 2.5 psi, works great. Picked it up at NAPA. HTH- SR

Thanks for the reply, SkidRoe. Good point on the pump type, I would not have thought to check that. I did talk to my local NAPA guy and he found one that matched the 4.5 psi that matches the stock pump spec. I think I'll start a new thread as I have more questions specific to this. As for this thread, it is still odd that the current issue started all of a sudden like it did. I did take the pump off and it appears to function as it does move fuel well off the machine when actuated manually. I did find that there is some play in the placement of the pump on the block but tweaking it in any direction did not seem to have any effect.

 

[LazyKG]

Thanks for the reply, SkidRoe. Good point on the pump type, I would not have thought to check that. I did talk to my local NAPA guy and he found one that matched the 4.5 psi that matches the stock pump spec. I think I'll start a new thread as I have more questions specific to this. As for this thread, it is still odd that the current issue started all of a sudden like it did. I did take the pump off and it appears to function as it does move fuel well off the machine when actuated manually. I did find that there is some play in the placement of the pump on the block but tweaking it in any direction did not seem to have any effect.

Follow up - turns out the problem was not with the pump, just dirt in the carb. See subsequent thread: http://www.skidsteerforum.com/DesktopDefault.aspx?tabid=54&frmView=ShowPost&PostID=89420

 

[SkidRoe]

Follow up - turns out the problem was not with the pump, just dirt in the carb. See subsequent thread: http://www.skidsteerforum.com/DesktopDefault.aspx?tabid=54&frmView=ShowPost&PostID=89420

Great!! Thanks for the update!! Cheers - SR