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Another Briggs Quantum 675 dies after about 5 minutes.
#1
T
tuit
T
tuit
Hi everybody, long time lurker but a newbie to the forum with first post. I rebuild transmissions at a local Ford dealership but never worked on small engines until now. I have a 5 year old Snapper Hi-vac mower with a Briggs and Stratton Quantum 6.75hp motor. Numbers on the motor is 125K02 - 0141 - E1. Problem is after about 5 minutes of cutting the motor starts cutting out, rpm drops down to about idle speed then dies. Feels like it is running out of fuel. Have to wait about 30-45 minutes before it will start then do the same thing after a couple of minutes. Tried pushing the primer bulb and loosen gas cap before it dies but does not make any difference. Did check oil level, it is on full mark with 30w oil. It's not flooding down, it doesn't smoke nor smell like its running rich. First time it happened I pulled the plug and checked for spark, didn't see a spark so tried a new plug, no change. Being i am trying to do this by myself, i can not get a good pull on the starter rope and see the plug spark at the same time. figured that i would bite the bullet and check the spark the old fashion way, pulled the spark plug back out, held the coil wire lead and pulled the cord as much as i could to turn it over to feel how hard the coil bites. Coil did not bite as hard as I thought it should so next day went to mower shop to get a new coil. Was told that they don't have many coil problems, they might replace one coil a year. They also stated that it does not produce a strong spark until around 1700 rpm. I bought the new coil anyway, also bought a carburetor overhaul kit and another spark plug while I was there. Ended up speeding $84 for the three pieces. Put the new coil on and set the air gap at .010 and replaced the plug. Started and let it run to see if I fixed the problem, they were right, it was not the coil. Pulled the plastic cowling, fuel tank and carburetor. Their is no in-line fuel filter on the model. Removed to float bowel, it was clean as a whistle inside, no water, dirt or rust inside. Cleaned everything with carb cleaner, ran wire thru all the passages and thru the jet then blew off with compressed air. Checked float level and replaced all the gaskets. Reassembled, filled with gas (I have alway used premium unleaded gas with Briggs fuel stabilizer), no change- still feels like it starving for gas. Pulled back apart, even though i have good fuel flow out of fuel tank, i ran an old speedometer chain couple of inches into fuel tank nipple until it hit what felt solid- assumed it was the side of tank (speedometer chain is what makes the speedometer turn in older cars. It's about 1/8 thick metal/brass cable and very flexible) it's not restricted then replaced fuel line- no change. Really surprised there is no kind of fuel filer on this motor. By this time starting to get pissed. Pulled carb off again, replaced needle and seat this time. Reassembled again, let run around 10 minutes. Didn't die as usual but rpm did start dropping and sputtering. Something I did notice threw out all of this, did not check compression but feels like its good as it is hard to pull starter rope. With motor running and air filter off, I see a fine mist of gas puffing out of carburetor. I assume it is from the mechanical compression release but I could be wrong.
I must be over looking something simple causing this to die but I'll be damned if I can think of what it could be. Next thing, I had no idea I could buy another motor with shipping for under 200 bucks from small engine suppler dot com. I emailed them info on what motor i had, they respoded with this link- Search for: 126L02-1625 -have already spent half of what a new motor costs. Not sure if I should just cut my losses and get another motor or keep screwing with this one?
Thanks in advance for any other suggestions or ideas.
Hal
I must be over looking something simple causing this to die but I'll be damned if I can think of what it could be. Next thing, I had no idea I could buy another motor with shipping for under 200 bucks from small engine suppler dot com. I emailed them info on what motor i had, they respoded with this link- Search for: 126L02-1625 -have already spent half of what a new motor costs. Not sure if I should just cut my losses and get another motor or keep screwing with this one?
Thanks in advance for any other suggestions or ideas.
Hal
#2
jroske
jroske
I would check the Valve clearances. Once the engine heats up the tolerances that are there disappear and the valves are not sealing properly.
#3
G
Gsnod
G
Gsnod
tuit -- I have this same issue on a B&S engine, and it does the same thing. Runs well for about 5 minutes, and then sputters and dies. I checked for spark, to determine whether the coil was firing when it got hot. I did have spark, leading me to believe it is not a coil issue. I have an extra coil that I can put on while I've got it apart.
Tomorrow I'll pull the head and adjust the valves. What leads me to thin that the valves might be involved is I have the same fine mist of gas being pushed out of the throat of the carb.
JROSKE -- is it likely that my coil, even though it produces spark, gets weaker as it warms up and then does not have a strong enough spark to run the engine? OR, should I move to adjusting the valves as suggested?
Tomorrow I'll pull the head and adjust the valves. What leads me to thin that the valves might be involved is I have the same fine mist of gas being pushed out of the throat of the carb.
JROSKE -- is it likely that my coil, even though it produces spark, gets weaker as it warms up and then does not have a strong enough spark to run the engine? OR, should I move to adjusting the valves as suggested?
Hi everybody, long time lurker but a newbie to the forum with first post. I rebuild transmissions at a local Ford dealership but never worked on small engines until now. I have a 5 year old Snapper Hi-vac mower with a Briggs and Stratton Quantum 6.75hp motor. Numbers on the motor is 125K02 - 0141 - E1. Problem is after about 5 minutes of cutting the motor starts cutting out, rpm drops down to about idle speed then dies. Feels like it is running out of fuel. Have to wait about 30-45 minutes before it will start then do the same thing after a couple of minutes. Tried pushing the primer bulb and loosen gas cap before it dies but does not make any difference. Did check oil level, it is on full mark with 30w oil. It's not flooding down, it doesn't smoke nor smell like its running rich. First time it happened I pulled the plug and checked for spark, didn't see a spark so tried a new plug, no change. Being i am trying to do this by myself, i can not get a good pull on the starter rope and see the plug spark at the same time. figured that i would bite the bullet and check the spark the old fashion way, pulled the spark plug back out, held the coil wire lead and pulled the cord as much as i could to turn it over to feel how hard the coil bites. Coil did not bite as hard as I thought it should so next day went to mower shop to get a new coil. Was told that they don't have many coil problems, they might replace one coil a year. They also stated that it does not produce a strong spark until around 1700 rpm. I bought the new coil anyway, also bought a carburetor overhaul kit and another spark plug while I was there. Ended up speeding $84 for the three pieces. Put the new coil on and set the air gap at .010 and replaced the plug. Started and let it run to see if I fixed the problem, they were right, it was not the coil. Pulled the plastic cowling, fuel tank and carburetor. Their is no in-line fuel filter on the model. Removed to float bowel, it was clean as a whistle inside, no water, dirt or rust inside. Cleaned everything with carb cleaner, ran wire thru all the passages and thru the jet then blew off with compressed air. Checked float level and replaced all the gaskets. Reassembled, filled with gas (I have alway used premium unleaded gas with Briggs fuel stabilizer), no change- still feels like it starving for gas. Pulled back apart, even though i have good fuel flow out of fuel tank, i ran an old speedometer chain couple of inches into fuel tank nipple until it hit what felt solid- assumed it was the side of tank (speedometer chain is what makes the speedometer turn in older cars. It's about 1/8 thick metal/brass cable and very flexible) it's not restricted then replaced fuel line- no change. Really surprised there is no kind of fuel filer on this motor. By this time starting to get pissed. Pulled carb off again, replaced needle and seat this time. Reassembled again, let run around 10 minutes. Didn't die as usual but rpm did start dropping and sputtering. Something I did notice threw out all of this, did not check compression but feels like its good as it is hard to pull starter rope. With motor running and air filter off, I see a fine mist of gas puffing out of carburetor. I assume it is from the mechanical compression release but I could be wrong.
I must be over looking something simple causing this to die but I'll be damned if I can think of what it could be. Next thing, I had no idea I could buy another motor with shipping for under 200 bucks from small engine suppler dot com. I emailed them info on what motor i had, they respoded with this link- Search for: 126L02-1625 -have already spent half of what a new motor costs. Not sure if I should just cut my losses and get another motor or keep screwing with this one?
Thanks in advance for any other suggestions or ideas.
Hal
#4
R
Rivets
R
Rivets
Have you checked to see if the fuel cap vent is clogged. This will create a vaccum in the tank, not allowing fuel to flow. Run unit with the cap loose and see it the problem occurs. I doubt that it is the valves on an L-head engine.
#5
G
Gsnod
G
Gsnod
Thanks Rivets -- Yes, I actually took the fuel cap off the mower, and it did the same thing. I also have a new fuel line on it. It will restart soon after it dies out, but then repeats the action of coughing/stuttering and dies....Carb was soaked and cleaned, and the bowl always seems to have fuel in it.
Any other suggestions?
Any other suggestions?
Have you checked to see if the fuel cap vent is clogged. This will create a vaccum in the tank, not allowing fuel to flow. Run unit with the cap loose and see it the problem occurs. I doubt that it is the valves on an L-head engine.
#6
I
ILENGINE
I
ILENGINE
I don't think that engine has the compression release. I would go ahead and take off the muffler, and take the breather off and check the valve clearances just to make sure it isn't floating one of the valves. I think it could be floating the intake valve slightly due to you saying that it is spraying fuel back out of the carb.
Had one a few years ago that was hard to start and had no power. Found out that the exhaust seat wasn't square with the valve, so it wasn't sealing causing compression problems. More was a new unit that the customer had purchased just a couple weeks before. Briggs warrantied the recutting of the seat to align it with the valve.
Had one a few years ago that was hard to start and had no power. Found out that the exhaust seat wasn't square with the valve, so it wasn't sealing causing compression problems. More was a new unit that the customer had purchased just a couple weeks before. Briggs warrantied the recutting of the seat to align it with the valve.
#7
jroske
jroske
Tomorrow I'll pull the head and adjust the valves. What leads me to thin that the valves might be involved is I have the same fine mist of gas being pushed out of the throat of the carb.
JROSKE -- is it likely that my coil, even though it produces spark, gets weaker as it warms up and then does not have a strong enough spark to run the engine? OR, should I move to adjusting the valves as suggested?[/QUOTE]
I would still check the valves. I had one the other day had the same issue. I lapped both and had to take about .003 off of one of them and it runs great. No complaints from the customer at all.
JROSKE -- is it likely that my coil, even though it produces spark, gets weaker as it warms up and then does not have a strong enough spark to run the engine? OR, should I move to adjusting the valves as suggested?[/QUOTE]
I would still check the valves. I had one the other day had the same issue. I lapped both and had to take about .003 off of one of them and it runs great. No complaints from the customer at all.
#8
G
Gsnod
G
Gsnod
I'll pull the muffler and breather tonight to check valve clearances. I don't have a spring compressor, so (while difficult), if I need to pull the valves for tail end gringing, getting the spring retainer off and on is difficult....but not impossible. Without the head off, as long as both valves are seated, I'm OK to check clearances, correct?
I don't have a grinding wheel....will a file work OK for this purpose?
I would still check the valves. I had one the other day had the same issue. I lapped both and had to take about .003 off of one of them and it runs great. No complaints from the customer at all.[/QUOTE]
I don't have a grinding wheel....will a file work OK for this purpose?
Tomorrow I'll pull the head and adjust the valves. What leads me to thin that the valves might be involved is I have the same fine mist of gas being pushed out of the throat of the carb.
JROSKE -- is it likely that my coil, even though it produces spark, gets weaker as it warms up and then does not have a strong enough spark to run the engine? OR, should I move to adjusting the valves as suggested?
I would still check the valves. I had one the other day had the same issue. I lapped both and had to take about .003 off of one of them and it runs great. No complaints from the customer at all.[/QUOTE]
#9
jroske
Do not use a grinding wheel.. you. Will take way too much off and end up replacing the valve. I use fine wet/dry sandpaper or fine file.
jroske
[/QUOTE]I'll pull the muffler and breather tonight to check valve clearances. I don't have a spring compressor, so (while difficult), if I need to pull the valves for tail end gringing, getting the spring retainer off and on is difficult....but not impossible. Without the head off, as long as both valves are seated, I'm OK to check clearances, correct?
I don't have a grinding wheel....will a file work OK for this purpose?
I would still check the valves. I had one the other day had the same issue. I lapped both and had to take about .003 off of one of them and it runs great. No complaints from the customer at all.
Do not use a grinding wheel.. you. Will take way too much off and end up replacing the valve. I use fine wet/dry sandpaper or fine file.
#10
T
tuit
T
tuit
Sorry for the delay getting back, busier then a cat covering for the last few days. Thanks for all the replies, never thought I would get this kind of response.
Don't feel any loss of compression while trying to restart, if intake valve was hanging open enough to stall engine would expect to feel a easier pull on rope or a gas soaked air filter. Granted I have a fine mist but not enough to to leave any residue on the filter.
Pulled every thing back apart again that I had done previously double checking every thing, carefully reassembling found nothing. Only thing done different is pulled primer bulb out of housing to look and make sure it was not cracked or damaged which it was not.
Added gas, few pumps of the primer bulb, started right up. Let it run at full throttle for over 30 minutes, almost a full tank of gas and it didn't die the entire time. Figure this weekend will tell if I actually fixed anything or not. One way or another I'm going to make this problem go away. Dead set that it if it still continues to die i'm going to just order another motor and be done with it.
Will update this post as soon I cut the grass tomorrow.
Don't feel any loss of compression while trying to restart, if intake valve was hanging open enough to stall engine would expect to feel a easier pull on rope or a gas soaked air filter. Granted I have a fine mist but not enough to to leave any residue on the filter.
Pulled every thing back apart again that I had done previously double checking every thing, carefully reassembling found nothing. Only thing done different is pulled primer bulb out of housing to look and make sure it was not cracked or damaged which it was not.
Added gas, few pumps of the primer bulb, started right up. Let it run at full throttle for over 30 minutes, almost a full tank of gas and it didn't die the entire time. Figure this weekend will tell if I actually fixed anything or not. One way or another I'm going to make this problem go away. Dead set that it if it still continues to die i'm going to just order another motor and be done with it.
Will update this post as soon I cut the grass tomorrow.
#11
G
Gsnod
G
Gsnod
Thank you all for your guidance. I was able to grind the valve down, which then was adjustable to within specs. Next, it was all about putting it back together and pulling the cord....started right up!
Thank you all!
Thank you all!
Sorry for the delay getting back, busier then a cat covering for the last few days. Thanks for all the replies, never thought I would get this kind of response.
Don't feel any loss of compression while trying to restart, if intake valve was hanging open enough to stall engine would expect to feel a easier pull on rope or a gas soaked air filter. Granted I have a fine mist but not enough to to leave any residue on the filter.
Pulled every thing back apart again that I had done previously double checking every thing, carefully reassembling found nothing. Only thing done different is pulled primer bulb out of housing to look and make sure it was not cracked or damaged which it was not.
Added gas, few pumps of the primer bulb, started right up. Let it run at full throttle for over 30 minutes, almost a full tank of gas and it didn't die the entire time. Figure this weekend will tell if I actually fixed anything or not. One way or another I'm going to make this problem go away. Dead set that it if it still continues to die i'm going to just order another motor and be done with it.
Will update this post as soon I cut the grass tomorrow.