When it does it, it's more when it's running not when I shut it off. Not ether. Actually sounds like one of my older horses. Walks and farts at the same time. I'll try what you suggest.
Valve adjustment tolerence setting
- Thread starter Kruzer
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When it does it, it's more when it's running not when I shut it off. Not ether. Actually sounds like one of my older horses. Walks and farts at the same time. I'll try what you suggest.
I'm still getting the backfire or more a sputter from the muffler. On adjusting the valves, I know you get it to TDC and then 1/4" past it. When you check the exhaust valve do you keep the motor where it is or do you spin it again to another position? I tried all the other suggestions on fixing the sputter with no results. It does have a hard time starting even with a fresh battery.
Michael72
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Do as was advised by others....find TDC and 1/4" turn of fly wheel.... if both valves are closed (method) at this point you should not have to turn/re-adjust your flywheel... I do repeat the process until happy tho...if adjustment is good then its good... other issues at hand...albeit small ones...:forgot to add... have a look at your push rods and guides for any wear...if you pull rods out make sure to put them back as you found them 2cents
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I checked them and double checked them. All seem fine. I remember when this problem started. It was after I ran out of gas and the motor died. From that point on it started to have a mild backfire through the muffler. At times it would run fine but most times it would do it. I'm not sure if any of these were possible solutions but I tried running with out the cap, change the filter, ran seafoam through it. I didn't take the carb apart yet mostly because I'm not too sure what I'm looking for. The reason for thinking it's the valves is from different threads I read. Probably too much info I guess. The motor has about 250 hrs on it.
Michael72
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Just a shot in the dark here....not sure on muffler set up over there as it can vary... had a honda mower in some time back with a removable spark arrestor screen that was clogged...just removed and cleaned.... other than that with no fuel line, spark, issues etc....id replace the gasket and diaphragm in your carb and a general clean....if your diaphragm is dead it will feel a little dried up/ hard....cheap and easy to replace...did you hit anything with it lately?...tree stump etc... does engine seem hard to turn over as if battery is weak?
Thanks for the reply,
I'll try the spark arrester. It was mentioned before. Not sure where it is or if its removable. I didn't hit anything, just ran out of gas. It started do thing shortly after. I do mulch and maybe something worked it's way into the carb? Nothing was hit too. Not sure as the battery as it has one season on it. It has plenty of power as I put a snow plow on it and it doesn't struggle at all. I'll try looking at those suggestions. We're getting that blizzard soon here in Mass. This might be put on the back burner for a few days.
I'll try the spark arrester. It was mentioned before. Not sure where it is or if its removable. I didn't hit anything, just ran out of gas. It started do thing shortly after. I do mulch and maybe something worked it's way into the carb? Nothing was hit too. Not sure as the battery as it has one season on it. It has plenty of power as I put a snow plow on it and it doesn't struggle at all. I'll try looking at those suggestions. We're getting that blizzard soon here in Mass. This might be put on the back burner for a few days.
Michael72
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It would be in the muffler itself...if its a sealed unit then remove it and check if its towards exhaust port end (where it bolts to cylinder) only guessing as it might not have one but worth a look...might be worth checking the flywheel key while your at it...all I can say after that is to check air and fuel manifold just to illuminate any extra air intake etc :confused2: Happy Hunting :biggrin:
bertsmobile1
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In order to back fire through the muffler you need to be putting unburned fuel in there which gets ignited either by something that is red hot or by the following exhaust that is still burning.
Only 3 reasons why fuel does not burn in the cylinder.
Wrong air: fuel ratio
Compression too low
no spark ( includes wrong time spark )
Now the first two would cause consistant back fires
So the last is the prime suspect.
First try a new plug
Second remove the ignition cut off wire at the engine .
It is a small tubular connector with a funny cap.
This isolates the coil/s from the entire mower so if you have a bad safety switch it is not in circuit and neither is the IGNITION SWITCH . ( shouting intended to get your undivided attention )
Note THERE IS NO WAY TO TURN OFF THE ENGINE UNTILL YOU RECONNECT THIS WIRE so some caution is necessary .
If the problem goes away then tough luck as you now have to work out which switch is giving you grief.
Next trick is to run the mower without its hood & the engine without its cowl, in a dark place for a short time.
Carefully inspect all the wires coming out of the coil and you are looking for a spark sneaking out of the system some where escaping onto the engine and this goes all the way back to connector you dissconnected in the previous test.
This is best done after dark as some sparks can be really hard to see.
Also note I said a short time as running for more than 10 minues or so without the cowl can cause local overheating and distort the engine turning it into land fill.
Only 3 reasons why fuel does not burn in the cylinder.
Wrong air: fuel ratio
Compression too low
no spark ( includes wrong time spark )
Now the first two would cause consistant back fires
So the last is the prime suspect.
First try a new plug
Second remove the ignition cut off wire at the engine .
It is a small tubular connector with a funny cap.
This isolates the coil/s from the entire mower so if you have a bad safety switch it is not in circuit and neither is the IGNITION SWITCH . ( shouting intended to get your undivided attention )
Note THERE IS NO WAY TO TURN OFF THE ENGINE UNTILL YOU RECONNECT THIS WIRE so some caution is necessary .
If the problem goes away then tough luck as you now have to work out which switch is giving you grief.
Next trick is to run the mower without its hood & the engine without its cowl, in a dark place for a short time.
Carefully inspect all the wires coming out of the coil and you are looking for a spark sneaking out of the system some where escaping onto the engine and this goes all the way back to connector you dissconnected in the previous test.
This is best done after dark as some sparks can be really hard to see.
Also note I said a short time as running for more than 10 minues or so without the cowl can cause local overheating and distort the engine turning it into land fill.
Gone thru just about all suggested. As of now if I run it with the choke very slightly pulled out, the random backfire stops. This thing has been working its *** off as we have had over 40" of snow in the last couple of weeks ( and lot more on the way) and my snow blower crapped out. I have craftsman snow blade on it. I just put a new 340 CCA battery on it and starts easily so I'm guessing I got the valves right or really close. Where should I be looking? I didn't try Bert's last suggestion yet. I wanted to mention the choke first. If I have to pull the carb, I might wait and run it like it is if it don't hurt it. I'm not really confident in taking that apart.
Michael72
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Just a carb cleaning issue me thinks if not drawing any unwanted air....is there a fuel pump on her?... not sure of model specs but some will have a positive feed pipe that leads from OHV cover to fuel pump....check for any cracks in pipe etc....:confused2: