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Redmax EBZ-8001 SN (6100XXXX) Only runs on starter fluid
#1
W
wmbrower55
W
wmbrower55
I am trying to troubleshoot an issue that has been going on for a few months now. Just to point out a few items that have already been addressed:
1. New carb has been installed (brand new and complete not rebuilt)
2. New Muffler has been installed
3. All gaskets haev been replaced
4. New Fuel Filter and Fuel Lines
5. New Spark Plug
6. New Piston and Piston rings
7. Exhaust port has been cleaned
Has strong compression. Has strong spark. Will only run if I spray a little amount of starter fluid into the intake port or the spark plug port. Once the fluid burns up it will not run any longer. If I remove the spark plug I do not see or smell the gas mixture coming out of the spark plug. The carb has gas and can prime well. I revisited the piston and removed the intake manifold to get a look at the piston as it moves up and down in the cylinder case and I noticed that on the intake side the piston rings never get below the top of the intake port. I am not sure if that is the normal operation. I suspect that there is something wrong with this operation and that the gax is never getting pulled into the chamber hence the reason why no mixture comes out of the spark port and why the engine will not run on anything other than starter fluid. Does anyone have a similar experience or any thoughts or direction in which I can go? Thanks in advance for the help.
1. New carb has been installed (brand new and complete not rebuilt)
2. New Muffler has been installed
3. All gaskets haev been replaced
4. New Fuel Filter and Fuel Lines
5. New Spark Plug
6. New Piston and Piston rings
7. Exhaust port has been cleaned
Has strong compression. Has strong spark. Will only run if I spray a little amount of starter fluid into the intake port or the spark plug port. Once the fluid burns up it will not run any longer. If I remove the spark plug I do not see or smell the gas mixture coming out of the spark plug. The carb has gas and can prime well. I revisited the piston and removed the intake manifold to get a look at the piston as it moves up and down in the cylinder case and I noticed that on the intake side the piston rings never get below the top of the intake port. I am not sure if that is the normal operation. I suspect that there is something wrong with this operation and that the gax is never getting pulled into the chamber hence the reason why no mixture comes out of the spark port and why the engine will not run on anything other than starter fluid. Does anyone have a similar experience or any thoughts or direction in which I can go? Thanks in advance for the help.
#2
reynoldston
reynoldston
You are getting a good fuel flow to the carburetor? No solenoid on bottom of carburetor and if so its working OK. Your needle valve has to be sticking in the new carburetor.
#3
7394
7394
For the record: It used to run, right ? Does the intake have any possible air leak ?
I can't see how the piston stroke (length) would change..
I can't see how the piston stroke (length) would change..
#4
d_sharier
d_sharier
Okay, Let's start with a couple of questions, and please don't be offended if they seem over simplified.
When you replaced the carburetor, did you buy OEM (Zama I believe) or one of the knock off's?
A compression test is necessary, are you able to preform one and let us know the results? Around 150 pis is great. 110 psi and under is considered the problem area (at least in Stihl's opinion) Even with new rings it could still be low if the cylinder is out of round. Why did you replace them? Old rings scored? Cylinder wall scored?
If the plug is not getting "wet" when attempting to start it, then fuel delivery is the problem. I believe that this is a ported, 2 cycle engine. There are several things that play into fuel delivery. Compression is one of those, kind of. Not cylinder compression, but crankcase compression. When the piston travels up during the compression stroke it creates a negative pressure area in the crank case. Atmospheric air is then drawn in through the carburetor picking up the emulsified fuel mix and flowing into the crank case (that is why you only see the bottom of the piston on the intake side of the cylinder, buy design so fuel goes into bottom of crankcase) Then on the down stroke of the piston, the fuel mix in the crank case is pressurized causing the fuel mix to escape to the top side of the piston via the ports in the cylinder walls. That is the quick generic version anyway.
Now if the engine is not capable of creating enough of a vacuum to draw fuel in, it can certainly mimic a carburetor issue. Assuming that the carburetor is a new OEM replacement that hasn't been altered or disassembled, then it's likely not the issue.
Here is a list of things I would check.
1. Fuel lines attached appropriately. Line with filter to inlet side of carburetor, return line to tank attached to primer assembly. Air filter new? I guess I am assuming you are trying to start it with out one installed while working on it, but a clogged filter will inhibit fuel delivery as well.
2. Compression test on top side
3. Check the intake gasket and intake manifold to make sure the pulse or impulse path is open. Should be a little hole in gasket and manifold that need to open and aligned. Helps deliver a pulse of air to the fuel pump side of the carburetor that, in turn helps delivery fuel to the engine. Also check for cracks in the manifold. I can't tell you how many I have cracked from over tightening the screws.
4. Remove the muffler and pull engine over several times and check the plug to see if wet. I have heard of some new new CAT style mufflers being faulty when new and not allowing the air to escape through it. If the engine can't exhale the exhaust, then it can't inhale air and fuel mix.
5.One of the most important tests on 2 cycle equipment that gets overlooked all of the time is a Pressure and Vacuum test of the crank case. Several years ago, I learned through a lot of wasted and unpaid hours of labor, to add this test to my diagnostic list on all 2 cycle equipment that I work on. If an air leak is present in the crank case, it will mimic carburetor problems to the point of insanity. ( HaHa ask me how I know that)
Pressurizing the crank case will highlight any air leaks present. I.E. intake manifold, cylinder gasket, crank / oil seals (these are often the problem) sometimes even a hole in the casting. Imagine the piston traveling down to pressurize the crankcase and shoot the fuel mix up the ports. If all the air getting compressed just shoots out of a failed oil seal then the fuel mix can't be forced to the topside of the piston. Sometimes an engine will pass a pressure test, but fail a vacuum test, so both are necessary. When pressurized the lip on the oil seal is forced on the crankshaft making it seal. But during the vacuum test that lip may pull inward allowing air in. If so, then this suction will also happen during the compression stroke when the engine is trying to create a vacuum in the crankcase to draw air and fuel through the carburetor. Air follows the path of least resistance. If an oil seal is leaking it will draw from there first instead of pulling through the carburetor.
All of that may sound more intimidating than it really is. A 6 or 8 dollar oil seal has driven many of us crazy, probably more than once (at least myself anyway)
Before I got the 'appropriate" tools I would go to the hardware store and get some sheets of rubber gasket material. Cut a triangle shaped piece that will fit between the muffler and cylinder, and one that will fit between the carburetor and intake manifold. Put the piston to top dead center (TDC). I used the adapter for my compression tester to screw into the spark plug hole. It has a hole in it that will accept a piece of fuel line. Run a piece of fuel line into the hole and thread the adapter into the cylinder. I have a hand pump pressure gauge that will plug onto the line. I have heard of guys using a compressor for this, but warn against it. More than 7 or so PSI and you risk blowing out good seals. I usually pressurize to approximately 6-7 psi. Then with a spray bottle filled with soapy water, spray around all possible points for leaks. Look for bubbles, and fix leaks accordingly. Vacuum test is almost the same. I use a MityVac hand pump. Follow the same steps with out soapy water, don't want the engine to inhale any. Set vacuum and see if it holds. One thing to remember, if the vacuum holds, rotate the crankshaft through several positions and see if it holds. Sometimes vacuum leaks are positional.
Sorry for the information overload. I hope some of it helps.
When you replaced the carburetor, did you buy OEM (Zama I believe) or one of the knock off's?
A compression test is necessary, are you able to preform one and let us know the results? Around 150 pis is great. 110 psi and under is considered the problem area (at least in Stihl's opinion) Even with new rings it could still be low if the cylinder is out of round. Why did you replace them? Old rings scored? Cylinder wall scored?
If the plug is not getting "wet" when attempting to start it, then fuel delivery is the problem. I believe that this is a ported, 2 cycle engine. There are several things that play into fuel delivery. Compression is one of those, kind of. Not cylinder compression, but crankcase compression. When the piston travels up during the compression stroke it creates a negative pressure area in the crank case. Atmospheric air is then drawn in through the carburetor picking up the emulsified fuel mix and flowing into the crank case (that is why you only see the bottom of the piston on the intake side of the cylinder, buy design so fuel goes into bottom of crankcase) Then on the down stroke of the piston, the fuel mix in the crank case is pressurized causing the fuel mix to escape to the top side of the piston via the ports in the cylinder walls. That is the quick generic version anyway.
Now if the engine is not capable of creating enough of a vacuum to draw fuel in, it can certainly mimic a carburetor issue. Assuming that the carburetor is a new OEM replacement that hasn't been altered or disassembled, then it's likely not the issue.
Here is a list of things I would check.
1. Fuel lines attached appropriately. Line with filter to inlet side of carburetor, return line to tank attached to primer assembly. Air filter new? I guess I am assuming you are trying to start it with out one installed while working on it, but a clogged filter will inhibit fuel delivery as well.
2. Compression test on top side
3. Check the intake gasket and intake manifold to make sure the pulse or impulse path is open. Should be a little hole in gasket and manifold that need to open and aligned. Helps deliver a pulse of air to the fuel pump side of the carburetor that, in turn helps delivery fuel to the engine. Also check for cracks in the manifold. I can't tell you how many I have cracked from over tightening the screws.
4. Remove the muffler and pull engine over several times and check the plug to see if wet. I have heard of some new new CAT style mufflers being faulty when new and not allowing the air to escape through it. If the engine can't exhale the exhaust, then it can't inhale air and fuel mix.
5.One of the most important tests on 2 cycle equipment that gets overlooked all of the time is a Pressure and Vacuum test of the crank case. Several years ago, I learned through a lot of wasted and unpaid hours of labor, to add this test to my diagnostic list on all 2 cycle equipment that I work on. If an air leak is present in the crank case, it will mimic carburetor problems to the point of insanity. ( HaHa ask me how I know that)
Pressurizing the crank case will highlight any air leaks present. I.E. intake manifold, cylinder gasket, crank / oil seals (these are often the problem) sometimes even a hole in the casting. Imagine the piston traveling down to pressurize the crankcase and shoot the fuel mix up the ports. If all the air getting compressed just shoots out of a failed oil seal then the fuel mix can't be forced to the topside of the piston. Sometimes an engine will pass a pressure test, but fail a vacuum test, so both are necessary. When pressurized the lip on the oil seal is forced on the crankshaft making it seal. But during the vacuum test that lip may pull inward allowing air in. If so, then this suction will also happen during the compression stroke when the engine is trying to create a vacuum in the crankcase to draw air and fuel through the carburetor. Air follows the path of least resistance. If an oil seal is leaking it will draw from there first instead of pulling through the carburetor.
All of that may sound more intimidating than it really is. A 6 or 8 dollar oil seal has driven many of us crazy, probably more than once (at least myself anyway)
Before I got the 'appropriate" tools I would go to the hardware store and get some sheets of rubber gasket material. Cut a triangle shaped piece that will fit between the muffler and cylinder, and one that will fit between the carburetor and intake manifold. Put the piston to top dead center (TDC). I used the adapter for my compression tester to screw into the spark plug hole. It has a hole in it that will accept a piece of fuel line. Run a piece of fuel line into the hole and thread the adapter into the cylinder. I have a hand pump pressure gauge that will plug onto the line. I have heard of guys using a compressor for this, but warn against it. More than 7 or so PSI and you risk blowing out good seals. I usually pressurize to approximately 6-7 psi. Then with a spray bottle filled with soapy water, spray around all possible points for leaks. Look for bubbles, and fix leaks accordingly. Vacuum test is almost the same. I use a MityVac hand pump. Follow the same steps with out soapy water, don't want the engine to inhale any. Set vacuum and see if it holds. One thing to remember, if the vacuum holds, rotate the crankshaft through several positions and see if it holds. Sometimes vacuum leaks are positional.
Sorry for the information overload. I hope some of it helps.
#5
J
johnsess
J
johnsess
I am trying to troubleshoot an issue that has been going on for a few months now. Just to point out a few items that have already been addressed:
1. New carb has been installed (brand new and complete not rebuilt)
2. New Muffler has been installed
3. All gaskets haev been replaced
4. New Fuel Filter and Fuel Lines
5. New Spark Plug
6. New Piston and Piston rings
7. Exhaust port has been cleaned
Has strong compression. Has strong spark. Will only run if I spray a little amount of starter fluid into the intake port or the spark plug port. Once the fluid burns up it will not run any longer. If I remove the spark plug I do not see or smell the gas mixture coming out of the spark plug. The carb has gas and can prime well. I revisited the piston and removed the intake manifold to get a look at the piston as it moves up and down in the cylinder case and I noticed that on the intake side the piston rings never get below the top of the intake port. I am noure if that is the normal operation. I suspect that there is something wrong with this operation and that the gax is never getting pulled into the chamber hence the reason why no mixture comes out of the spark port and why the engine will not run on anything other than starter fluid. Does anyone have a similar experience or any thoughts or direction in which I can go? Thanks in advance for the help.[/QUOTE
Is impulse line not cracked and connected to carb? It activates the pump in carb via pressure/vacuum generated by piston moving up and down in cylinder.
#6
d_sharier
This statement is not accurate in regards to a ported 2-cycle engine. The top of the piston will never brake the plane of the intake port. It would not run and operate if that were the case. The fuel mix must be drawn into the crankcase underneath the piston. If this did not happen then the crankshaft journal, crankshaft bearings, connecting rod, wrist pin, etc. etc. would never get oiled. The fuel is drawn in under the piston and then shot up the ports to the combustion chamber.
d_sharier
The top of the piston should extend below the top of the intake port at bottom dead center. If the piston is beveled on top, perhaps it was installed 180 degrees off. If piston is flat on top, perhaps it's the wrong piston.
This statement is not accurate in regards to a ported 2-cycle engine. The top of the piston will never brake the plane of the intake port. It would not run and operate if that were the case. The fuel mix must be drawn into the crankcase underneath the piston. If this did not happen then the crankshaft journal, crankshaft bearings, connecting rod, wrist pin, etc. etc. would never get oiled. The fuel is drawn in under the piston and then shot up the ports to the combustion chamber.
#7
W
wmbrower55
W
wmbrower55
Guys,
First off thanks for the input as it is much appreciated. I apologize for not replying sooner... the holidays have been rather busy and I haven't been receiving emails notifying me that someone has responded to my thread. After days of thinking about this I think that D_Sharier is right. I went back to some oldbooks of mine to refresh my troubleshooting methods and a vaccum and pressure test is definitly needed. I can't think of any other reason why the fuel is not being delivered. I am just not sure if it is because it never makes it into the crankshaft or if it ever makes it out of it. For clarification the carb is a Walbro that I ordered from redmaxpartsdirect.com using the serial number of the unit. The original piston was replaced because it has a huge dent on the head of it and the rings were stuck on. The cylinder walls suprisingly has no scratches or bores so I replaced what I needed. I will report back with what i find after the tests. Thanks again to all of you and D_sharier you have confirmed what I have been mulling over for the past few days.
First off thanks for the input as it is much appreciated. I apologize for not replying sooner... the holidays have been rather busy and I haven't been receiving emails notifying me that someone has responded to my thread. After days of thinking about this I think that D_Sharier is right. I went back to some oldbooks of mine to refresh my troubleshooting methods and a vaccum and pressure test is definitly needed. I can't think of any other reason why the fuel is not being delivered. I am just not sure if it is because it never makes it into the crankshaft or if it ever makes it out of it. For clarification the carb is a Walbro that I ordered from redmaxpartsdirect.com using the serial number of the unit. The original piston was replaced because it has a huge dent on the head of it and the rings were stuck on. The cylinder walls suprisingly has no scratches or bores so I replaced what I needed. I will report back with what i find after the tests. Thanks again to all of you and D_sharier you have confirmed what I have been mulling over for the past few days.
#8
B
bertsmobile1
Chap & nasty way of verifing the carb is to pull it off open both the choke & trottle fully and blow through the air intake.
If you have a vacuum that blows it is better than using compressed air but that will work in fact a leaf bolwer will also work but you will need to grow an extra hand to hold everything together.
Just pull the carb off and leave it connected to the fuel tank.
If it is working & connected correctly then you will see & feel fuel being blown out of the engine side although it may take 3 or 4 minutes.
I use a compressor air gun with a 1/4" tube on it so I can direct the air strait across the venturi opening.
Just 1 word of caution, you are blowing an explosive mix of fuel & air out of the carb so just bear in mind where all that potential fire risk is heading towards.
now if you do not get a fuel mix comming out of the carb then check your fuel line connections.
The one nearest the primer bulb is the return line to the fuel tank and the one furthest away is the fuel delivery line.
The primer sucks the fuel through the carb It does not pump fuel into the carb and it is very easy to get things mixed up.
If you still see no fuel then I connect the crab to a spare tank with a known good filter in it , suspend the tank above the carb and repeat the blow test.
If it worke with the auxilliary tank then I know I am looking at the fuel ines in the real tank and most likely the fuel filter.
easy for me because I have all the plumbing supplies on hand , a bit harder for you but for the purpose of this test some cheap pvc tube will be good enough .
B
bertsmobile1
Guys,
First off thanks for the input as it is much appreciated. I apologize for not replying sooner... the holidays have been rather busy and I haven't been receiving emails notifying me that someone has responded to my thread. After days of thinking about this I think that D_Sharier is right. I went back to some oldbooks of mine to refresh my troubleshooting methods and a vaccum and pressure test is definitly needed. I can't think of any other reason why the fuel is not being delivered. I am just not sure if it is because it never makes it into the crankshaft or if it ever makes it out of it. For clarification the carb is a Walbro that I ordered from redmaxpartsdirect.com using the serial number of the unit. The original piston was replaced because it has a huge dent on the head of it and the rings were stuck on. The cylinder walls suprisingly has no scratches or bores so I replaced what I needed. I will report back with what i find after the tests. Thanks again to all of you and D_sharier you have confirmed what I have been mulling over for the past few days.
Chap & nasty way of verifing the carb is to pull it off open both the choke & trottle fully and blow through the air intake.
If you have a vacuum that blows it is better than using compressed air but that will work in fact a leaf bolwer will also work but you will need to grow an extra hand to hold everything together.
Just pull the carb off and leave it connected to the fuel tank.
If it is working & connected correctly then you will see & feel fuel being blown out of the engine side although it may take 3 or 4 minutes.
I use a compressor air gun with a 1/4" tube on it so I can direct the air strait across the venturi opening.
Just 1 word of caution, you are blowing an explosive mix of fuel & air out of the carb so just bear in mind where all that potential fire risk is heading towards.
now if you do not get a fuel mix comming out of the carb then check your fuel line connections.
The one nearest the primer bulb is the return line to the fuel tank and the one furthest away is the fuel delivery line.
The primer sucks the fuel through the carb It does not pump fuel into the carb and it is very easy to get things mixed up.
If you still see no fuel then I connect the crab to a spare tank with a known good filter in it , suspend the tank above the carb and repeat the blow test.
If it worke with the auxilliary tank then I know I am looking at the fuel ines in the real tank and most likely the fuel filter.
easy for me because I have all the plumbing supplies on hand , a bit harder for you but for the purpose of this test some cheap pvc tube will be good enough .