600 leaking gas

[bob600]

Okay my 600 is leaking gas from somewhere on the mechanical fuel pump. It did this once before and I tightened up all of the screws around the rim of it and then next time I used it it seemed to not leak anymore, but now today after use it started leaking again. I am wondering if it only does this when it gets hot. Maybe a small crack somewhere? Anyway,, does anyone know what info I need to bring with me for when I go to NAPA to get a gasket set? I assume a carb-rebuild set would have the fuel pump gasket? Should I just take off that bowl on the fuel pump and put some RTV on the seal? It is hard to tell exactly where the fuel is leaking from--it is a fairly constant drip/stream. Last time I went to NAPA I brought the engine model number, but he said that they needed the carb model number. However, does the fuel pump gasket get ordered off the carb number or off the engine number?

 

[Tazza]

Personally, i would try the silicone route first. Pretty sure the carb kit won't have the gaskets for the fuel pump.

 

[BobMelroe]

Personally, i would try the silicone route first. Pretty sure the carb kit won't have the gaskets for the fuel pump.

Does your 600 still have the Wisconsin VH4D engine in it? If so I have a pump I can send you if you like. It's used, but worked and didn't leak. It's off the engine that was in mine which went to hell, would have cost way to much to rebuild it, so I swapped it out. If you can't get yours fixed let me know. I'll give you the pump, all you have to do is pay the shipping on it.
My book lists the Bobcat part number for the fuel pump as: 6516374. There is no rebuild kit part number listed, it just says "NSS".
Wisconsin lists the pump as part #LP38ES1, and rebuild kit as part #LQ46 Look here---> http://www.wisconsinmotors.com/partc/optsaccess/fuel_pumps.pdf
The New York distributor they list is:
Pitt Auto Electric Co.
1241 Freedom Road
Cranberry Twp PA
800-245-0711
Hope this helps.......

 

[bob600]

Does your 600 still have the Wisconsin VH4D engine in it? If so I have a pump I can send you if you like. It's used, but worked and didn't leak. It's off the engine that was in mine which went to hell, would have cost way to much to rebuild it, so I swapped it out. If you can't get yours fixed let me know. I'll give you the pump, all you have to do is pay the shipping on it.
My book lists the Bobcat part number for the fuel pump as: 6516374. There is no rebuild kit part number listed, it just says "NSS".
Wisconsin lists the pump as part #LP38ES1, and rebuild kit as part #LQ46 Look here---> http://www.wisconsinmotors.com/partc/optsaccess/fuel_pumps.pdf
The New York distributor they list is:
Pitt Auto Electric Co.
1241 Freedom Road
Cranberry Twp PA
800-245-0711
Hope this helps.......

I think I have the VF4D. I am new to this so I am not 100% sure what I have. The engine started behaving eratically last night, ans so I thought I was runing out of gas, I refilled the tank and now it won't start. I disconnected the metal line from the fuel pump to the carb and no gas was coming out when the engine turned over, so I took the fuel pumpo apart and cleaned the brass screen etc. When I put it back to gether after a couple cranks it started spurting out gas. I put it back together and tried to start it, but when it starts it either quits fter a second, or will only run at super low idle, and if I try to give it more gas it stalls out--I think it is either gas starvtion or it is flooding! I can't tell which. Do people ever bypass the mechanical fuel pump with an electrical one? I am kinda screwed right now because I have it stuck out in the middle of my yard.

 

[sledesigns]

I think I have the VF4D. I am new to this so I am not 100% sure what I have. The engine started behaving eratically last night, ans so I thought I was runing out of gas, I refilled the tank and now it won't start. I disconnected the metal line from the fuel pump to the carb and no gas was coming out when the engine turned over, so I took the fuel pumpo apart and cleaned the brass screen etc. When I put it back to gether after a couple cranks it started spurting out gas. I put it back together and tried to start it, but when it starts it either quits fter a second, or will only run at super low idle, and if I try to give it more gas it stalls out--I think it is either gas starvtion or it is flooding! I can't tell which. Do people ever bypass the mechanical fuel pump with an electrical one? I am kinda screwed right now because I have it stuck out in the middle of my yard.

Luckily, release the brake, move the handles to neutral and pull it to where you want it. No hydro-fluid-lock, just simple clutches, Nice! (I dread the day I have to remove the pump to yank a hydro-Bob around) Gas pump option #2 for you: 12v automotive pump from autoparts store. Thats whats been done to my M600. (I dont recommend a wild Holley, Mallory, etc race pump, they seem to have a short life...but look and sound cool for awhile...dont ask -Scott

 

[BobMelroe]

I think I have the VF4D. I am new to this so I am not 100% sure what I have. The engine started behaving eratically last night, ans so I thought I was runing out of gas, I refilled the tank and now it won't start. I disconnected the metal line from the fuel pump to the carb and no gas was coming out when the engine turned over, so I took the fuel pumpo apart and cleaned the brass screen etc. When I put it back to gether after a couple cranks it started spurting out gas. I put it back together and tried to start it, but when it starts it either quits fter a second, or will only run at super low idle, and if I try to give it more gas it stalls out--I think it is either gas starvtion or it is flooding! I can't tell which. Do people ever bypass the mechanical fuel pump with an electrical one? I am kinda screwed right now because I have it stuck out in the middle of my yard.

If it's the original engine it probably is the VF4D. It has a tapered output shaft where the variable sheave mounts. The tag on the motor should say, if there is one. It sounds like either something is restricting the fuel flow, or the diaphragm in the fuel pump is ruptured. Or it's sucking water or other gunk. The easiest way to get gunk out is to take a damp rag, wrap it around your blow gun and shove it into the filler neck. Put the end of the hose that goes to the fuel pump in a gas can or other container so you can see what comes out. It takes VERY LITTLE pressure when doing this so turn the compressor regulator down to about 5 or 10 lbs and go easy. This is assuming you have a compressor of course...... And I am assuming it was running halfway decent before (ie, no carburetor problems). The only other thing I can thing of, is the float is sticking. You could try tapping on the carb body a few time lightly with a wrench to see. If that doesn't work, it's probably not the float. Yes, you can add an electric pump, but you should run a return line to the tank or run it off a pressure switch, have it fused, AND add a manual override switch up front so you can shut it off in an emergency. Otherwise you could flood the carburetor, and maybe cause a fire. I think the diaphragm type pumps have this feature built in, but I would still have a switch up front. I still have that fuel pump if you are interested. Probably less than $10 to ship it to you via USPS. Not making any money off it, just hate to see you struggling.

 

[sledesigns]

If it's the original engine it probably is the VF4D. It has a tapered output shaft where the variable sheave mounts. The tag on the motor should say, if there is one. It sounds like either something is restricting the fuel flow, or the diaphragm in the fuel pump is ruptured. Or it's sucking water or other gunk. The easiest way to get gunk out is to take a damp rag, wrap it around your blow gun and shove it into the filler neck. Put the end of the hose that goes to the fuel pump in a gas can or other container so you can see what comes out. It takes VERY LITTLE pressure when doing this so turn the compressor regulator down to about 5 or 10 lbs and go easy. This is assuming you have a compressor of course...... And I am assuming it was running halfway decent before (ie, no carburetor problems). The only other thing I can thing of, is the float is sticking. You could try tapping on the carb body a few time lightly with a wrench to see. If that doesn't work, it's probably not the float. Yes, you can add an electric pump, but you should run a return line to the tank or run it off a pressure switch, have it fused, AND add a manual override switch up front so you can shut it off in an emergency. Otherwise you could flood the carburetor, and maybe cause a fire. I think the diaphragm type pumps have this feature built in, but I would still have a switch up front. I still have that fuel pump if you are interested. Probably less than $10 to ship it to you via USPS. Not making any money off it, just hate to see you struggling.

Oh, and the old school pro's zero$ method for eliminating the fuel tank, lines & pump from the equation on carbed engines: a small lawnmower fuel tank with a bit of fuel line hanging above the carb. Doesn't need to be way above or anything special, no measurable pressure needed. Head mechanic friend has what reminds me of an IV bag / fuel / nurse tank for troubleshooting like this. If it runs good with this apparatus, then the problem is in the stock line, pump, or tank......of course, if a guy wanted and you had a place on the cage to properly & permanantly mount a good 10g tank or fuel cell....a gravity feed fuel system would be an option

 

[bob600]

Oh, and the old school pro's zero$ method for eliminating the fuel tank, lines & pump from the equation on carbed engines: a small lawnmower fuel tank with a bit of fuel line hanging above the carb. Doesn't need to be way above or anything special, no measurable pressure needed. Head mechanic friend has what reminds me of an IV bag / fuel / nurse tank for troubleshooting like this. If it runs good with this apparatus, then the problem is in the stock line, pump, or tank......of course, if a guy wanted and you had a place on the cage to properly & permanantly mount a good 10g tank or fuel cell....a gravity feed fuel system would be an option

Okay, first thanks for all of the help. Bobmelroe thanks for the great offer--I wanted to wait to identify the problem 100% before having you ship that to me. And so with your advice I rigged up a lawn mower tank with a new filter and clean gas. Had it mounted above the carb. Engine will start and run at low speed only and then die out. Crank it for awhile and then it might start again and run at low speed, and then die out again. It will die out immediatly if I give it any throttle. I took apart the carb and emptied out the bowl and cleaned everything a little bit. I checked the spark from the coil and it looked okay. I looked at the points they seem okay, maybe I should gap them? Also maybe the timing is off? I also turned the carb adjust screw and now don't know where to start it now that the engine doesn't really run I can't adjust it properly. Is there a way to adjust the timing without the engine running?

 

[bob600]

Okay, first thanks for all of the help. Bobmelroe thanks for the great offer--I wanted to wait to identify the problem 100% before having you ship that to me. And so with your advice I rigged up a lawn mower tank with a new filter and clean gas. Had it mounted above the carb. Engine will start and run at low speed only and then die out. Crank it for awhile and then it might start again and run at low speed, and then die out again. It will die out immediatly if I give it any throttle. I took apart the carb and emptied out the bowl and cleaned everything a little bit. I checked the spark from the coil and it looked okay. I looked at the points they seem okay, maybe I should gap them? Also maybe the timing is off? I also turned the carb adjust screw and now don't know where to start it now that the engine doesn't really run I can't adjust it properly. Is there a way to adjust the timing without the engine running?

Oh, it must be a crankcase gas recirculation thing, but right before the carb there is a nipple that was open with nothing connected to it so I plugged it off for now and there is the same size of one on the oil filler neck. So the carb has been sucking air from that open filter for probably a long time. Anyway it doesn't need that to run though I don't think.

 

[bob600]

Oh, it must be a crankcase gas recirculation thing, but right before the carb there is a nipple that was open with nothing connected to it so I plugged it off for now and there is the same size of one on the oil filler neck. So the carb has been sucking air from that open filter for probably a long time. Anyway it doesn't need that to run though I don't think.

Guess I can check for spark at one of the plugs. Anyway it is really weird that it runs seeminlgy smooth for a little bit and then dies. It is going to be hard to diagnose something like that for me.

 

[sledesigns]

Guess I can check for spark at one of the plugs. Anyway it is really weird that it runs seeminlgy smooth for a little bit and then dies. It is going to be hard to diagnose something like that for me.

I would think the timing is fine if it runs smooth for a bit. Guessing a fuel side problem. Next to figure if its leaning out or flooding to cause it to die. Ive had needle & seat sticking issues on a V4 before & bits of debris that took several disasseblies of the carb to get out. I'll see if my 600 manuals have initial carb settings when I find them.

 

[BobMelroe]

I would think the timing is fine if it runs smooth for a bit. Guessing a fuel side problem. Next to figure if its leaning out or flooding to cause it to die. Ive had needle & seat sticking issues on a V4 before & bits of debris that took several disasseblies of the carb to get out. I'll see if my 600 manuals have initial carb settings when I find them.

I also doubt it's a timing issue. I uploaded scans of the carb from my Bobcat manual. But I can't make anything out. Can't upload a PDF. Maybe a Mod can help me out with that.

It almost seems as though it's leaning out when you crack the throttle. Try partial to full choke when you try to rev the engine and see if that makes a difference. If it does, it's a lean condition. Could be something is still plugged somewhere. Carbs can be pretty fussy at times. The open line you plugged off is the crankcase vent, I would hook that back up. I'll upload the last carb page in my book. I'm sure you know when dealing with carbs, everything has to be looked at very carefully. Even the tiniest speck of dirt can wreak havoc. If choking it doesn't help, it's something else and we can go from there.

 

[BobMelroe]

I also doubt it's a timing issue. I uploaded scans of the carb from my Bobcat manual. But I can't make anything out. Can't upload a PDF. Maybe a Mod can help me out with that.


It almost seems as though it's leaning out when you crack the throttle. Try partial to full choke when you try to rev the engine and see if that makes a difference. If it does, it's a lean condition. Could be something is still plugged somewhere. Carbs can be pretty fussy at times. The open line you plugged off is the crankcase vent, I would hook that back up. I'll upload the last carb page in my book. I'm sure you know when dealing with carbs, everything has to be looked at very carefully. Even the tiniest speck of dirt can wreak havoc. If choking it doesn't help, it's something else and we can go from there.

I just happened to think about this. The intake and exhaust manifolds are cast as one piece. The intake manifold is directly underneath the exhaust. There is a flat narrow casting "flange" that connects the two together. Check here very closely for cracks. Mine was cracked on the intake side and someone siliconed the dog crap out of it. This could cause your problems as well. Not saying it IS the cause, but it's one more thing to check. This would definitely make it lean out and not want to run.

 

[bob600]

I just happened to think about this. The intake and exhaust manifolds are cast as one piece. The intake manifold is directly underneath the exhaust. There is a flat narrow casting "flange" that connects the two together. Check here very closely for cracks. Mine was cracked on the intake side and someone siliconed the dog crap out of it. This could cause your problems as well. Not saying it IS the cause, but it's one more thing to check. This would definitely make it lean out and not want to run.

ARRGH, Okay, I went and took out a spark plug today as it got too dark to check them at night. They were totally black, so I am keeping them to clean them but went and got a new set, Champion D16's, to try out hop[ing it would rev up and run smooth. Well it didn't really help. It seems with the right amount of playing with the distibutor timing, and the right amount of tweaking with the carb adjustment screw--the one accessed between the exhaust flange--I can get it to idle okay some of the time, but then when I go and give it gas it starts cycling(like revving up and then dying down etc) until it finally stalls out. Then it won't necessarily start again without more tweaking. I am wondering if anyone knows about how many turns to back the carb adjustment screw out to get close to the right mixture, and where from 12:00 approx the wire going to the condensor on the distrib should be. I have been trying the carb screw backed out around 2 turns from all the way in, and the distrib condensor wire around 11:00-ish. I think that maybe the choke was set at a little open when I got it and I made it shut all the way. Are you aying I should go through ll the adjustments with it set partially closed? Any and all help is appreiated, thanks

 

[bob600]

ARRGH, Okay, I went and took out a spark plug today as it got too dark to check them at night. They were totally black, so I am keeping them to clean them but went and got a new set, Champion D16's, to try out hop[ing it would rev up and run smooth. Well it didn't really help. It seems with the right amount of playing with the distibutor timing, and the right amount of tweaking with the carb adjustment screw--the one accessed between the exhaust flange--I can get it to idle okay some of the time, but then when I go and give it gas it starts cycling(like revving up and then dying down etc) until it finally stalls out. Then it won't necessarily start again without more tweaking. I am wondering if anyone knows about how many turns to back the carb adjustment screw out to get close to the right mixture, and where from 12:00 approx the wire going to the condensor on the distrib should be. I have been trying the carb screw backed out around 2 turns from all the way in, and the distrib condensor wire around 11:00-ish. I think that maybe the choke was set at a little open when I got it and I made it shut all the way. Are you aying I should go through ll the adjustments with it set partially closed? Any and all help is appreiated, thanks

I am still running with gas fed by gravity from my extra fuel tank, are you sure this will give me enough of a gas supply for the carb? thanks

 

[sledesigns]

I am still running with gas fed by gravity from my extra fuel tank, are you sure this will give me enough of a gas supply for the carb? thanks

Grab a nearby gas jug, pull the line off the carb (that comes from the lawn mower tank) and poke it in there. If its about a pissin' stream, plenty of gas. Dribbling wont quite feed it. A quote from the 600 book: " The main jet in carburetor is stationary and need no adjustment. Adjustment ofthe needle for idle jet should be made for best low speed operation while carburetor throttle is held closed by hand. Turning needle in nearer to its seat results in a heavier concentration. Turning needle out away from its seat results in a lighter concentration." So, the adjustment screw evidently is for air. Turn it out leans, turn it in richens. Like someone earlier said, one bit of dirt = problems. Hope thats not it.

 

[OldMachinist]

I also doubt it's a timing issue. I uploaded scans of the carb from my Bobcat manual. But I can't make anything out. Can't upload a PDF. Maybe a Mod can help me out with that.


It almost seems as though it's leaning out when you crack the throttle. Try partial to full choke when you try to rev the engine and see if that makes a difference. If it does, it's a lean condition. Could be something is still plugged somewhere. Carbs can be pretty fussy at times. The open line you plugged off is the crankcase vent, I would hook that back up. I'll upload the last carb page in my book. I'm sure you know when dealing with carbs, everything has to be looked at very carefully. Even the tiniest speck of dirt can wreak havoc. If choking it doesn't help, it's something else and we can go from there.

"Can't upload a PDF. Maybe a Mod can help me out with that."
When I want to post a pdf file I use mediafire http://www.mediafire.com/ It's simple and free. There are other free file hosting services around so use what ever you want.

 

[bob600]

"Can't upload a PDF. Maybe a Mod can help me out with that."
When I want to post a pdf file I use mediafire http://www.mediafire.com/ It's simple and free. There are other free file hosting services around so use what ever you want.

Okay, only because of help I have gotten here was I able to drive the bobcat out of the yard and back to my garage. After tweaking the timing and idle screw endlessly I adjusted the choke so it was on a little bit and then adjusted the timing and idle jet screw again and was ab;e to get it idling decently. Then by adjusteing the stop screw on the govener(?) I was able to get it to run roughly at full throttle. It stalled out a couple times driving back to the garage, but at least I was able to get it there. I am not sure exactly what the govener stop screw does or even how the govenor works. I am used to a car where the gas pedal is directly linked to the butterfly valve on the carb, and so no further adjustment is needed. The reason it would run and then stall I think is because the govenor would give it full throttle and then back off that is what was causing the cycling. Stay tuned for more info. Any hints on adjusting govenor thing would be great!!

 

[sledesigns]

Okay, only because of help I have gotten here was I able to drive the bobcat out of the yard and back to my garage. After tweaking the timing and idle screw endlessly I adjusted the choke so it was on a little bit and then adjusted the timing and idle jet screw again and was ab;e to get it idling decently. Then by adjusteing the stop screw on the govener(?) I was able to get it to run roughly at full throttle. It stalled out a couple times driving back to the garage, but at least I was able to get it there. I am not sure exactly what the govener stop screw does or even how the govenor works. I am used to a car where the gas pedal is directly linked to the butterfly valve on the carb, and so no further adjustment is needed. The reason it would run and then stall I think is because the govenor would give it full throttle and then back off that is what was causing the cycling. Stay tuned for more info. Any hints on adjusting govenor thing would be great!!

If you plan on keeping your 600, the maintenance book is the best attachment out there. I'll have to wait for wifey to show me how to scan in the governor pages this afternoon. I thought I'd read here about a place you could subscibe for online reading / printing of various Bobcat manuals. I know mine is blurry enough in the old book, let alone my less than pro scanning abilities. Good luck.