Outdoor Power Equipment and Small Engines - Oil Sludge and difficult pull start
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wattsje
03-20-07, 08:58 AM
I just bought a pressure washer at auction with a 6 HP B&S engine. I noticed the pull start was very difficult to pull and the oil was like sludge. My question is whether there is a product out there to run through the engine to clean out the sludge. Also, could this be the source of the pull start problem?
Thanks!
Thanks!
backyardwonder
03-20-07, 12:26 PM
If you bought it at an auction, anything is possible. My first thought is that the engine may have been tipped over at one time through rough handling, etc. and oil got up into the cylinder. This would increase compression to the point where the pull start could be very difficult.
Oil sludge could also result from the engine not being used for some time and/or the oil has never been changed regularily as it should be.
I would leave whatever oil is in there for the moment and just top it up with fresh oil. Then remove the spark plug and pull the cord a few times to work the oil around. If the cord is easier to pull now, the issue is very likely oil in the cylinder. Drop a couple of table spoons of gas into the cylinder, replace the spark plug and try to start it. If it fires, then stalls, you also have a fuel supply problem and will need to do the carb. If it fires and runs, let it idle about 5 minutes to warm up then shut it down and change the oil.
You should now be OK.
Oil sludge could also result from the engine not being used for some time and/or the oil has never been changed regularily as it should be.
I would leave whatever oil is in there for the moment and just top it up with fresh oil. Then remove the spark plug and pull the cord a few times to work the oil around. If the cord is easier to pull now, the issue is very likely oil in the cylinder. Drop a couple of table spoons of gas into the cylinder, replace the spark plug and try to start it. If it fires, then stalls, you also have a fuel supply problem and will need to do the carb. If it fires and runs, let it idle about 5 minutes to warm up then shut it down and change the oil.
You should now be OK.
puey61
03-20-07, 12:48 PM
I'll bet there are products out there that claim to remove sludge but I wouldn't buy it. Where's it going to go? Aside from disassembling the engine (which I would recommend since you have no way to know the service/maintenance history), I'd recommend simply changing the oil, run the engine for 1 hour at full throttle (be sure you have a wet-sump pump before doing this), change the oil again, operate the unit for a weeks worth of work, change the oil again one final time by running for 20 minutes just prior to dumping the oil. Are you sure the difficult pull start is related to the oil? And not a tight engine? Just more reason to get inside the engine and have a look and provide you opportunity to clean the sludge out.
geogrubb
03-20-07, 04:00 PM
I have always used a mixture of 1/2 30w oil and 1/2 Type F auto transmission fluid(the cheap stuff) to remove sludge in small engines, the transmission fluid does the cleaning. I put the mixture in and run the motor at idle for 10-20 minutes and drain and do it again until the oil is clean, usually 3 times. Then fill with new oil. I have been using it for 40yrs, since an old guy told me he could fix the rattling/sticky lifters in my 55 pontiac for .50, he checked the oil, it was down a quart, he poured in a quart of transmission fluid and within 10 minutes all the noise went away, I was amazed. Have a good one. Geo
Azis
03-20-07, 04:12 PM
Transmission fluid is an excellent detergent. It is also very acidic and corrosive and is not safe for a lot of seals and gaskets.
There are engine flushes such as "gunk" that are added to the oil prior to changing, ran to temp, then drained out with the old oil. Diesel fuel can also be used in this manner.
Some very high time engines may suffer from removing too much sludge as it may be part of what is holding it together, literally.
There are engine flushes such as "gunk" that are added to the oil prior to changing, ran to temp, then drained out with the old oil. Diesel fuel can also be used in this manner.
Some very high time engines may suffer from removing too much sludge as it may be part of what is holding it together, literally.
bontai Joe
03-21-07, 01:47 PM
I'll bet there are products out there that claim to remove sludge but I wouldn't buy it. Where's it going to go? Aside from disassembling the engine (which I would recommend since you have no way to know the service/maintenance history), I'd recommend simply changing the oil, run the engine for 1 hour at full throttle (be sure you have a wet-sump pump before doing this), change the oil again, operate the unit for a weeks worth of work, change the oil again one final time by running for 20 minutes just prior to dumping the oil. Are you sure the difficult pull start is related to the oil? And not a tight engine? Just more reason to get inside the engine and have a look and provide you opportunity to clean the sludge out.
This is the method I would recommend. Two or three oil changes after a couple of run cycles will clean out the engine with a minimum of expense and a minimum of damage. I'm not too sure that any solvent or other product used in the crankcase to clean will give you better results, with out risking damage to seals, or reducing lubrication while "cleaning" that might cause other problems. Might be perfectly fine, but I just don't know, that's why I'd stick with the suggestion above.
This is the method I would recommend. Two or three oil changes after a couple of run cycles will clean out the engine with a minimum of expense and a minimum of damage. I'm not too sure that any solvent or other product used in the crankcase to clean will give you better results, with out risking damage to seals, or reducing lubrication while "cleaning" that might cause other problems. Might be perfectly fine, but I just don't know, that's why I'd stick with the suggestion above.