I ran over a clump of high grass and the mower went from normal power to low power and will not go back to full power even after installing new plug, spraying carb and crankcase will lawnmower spray. it also shakes a little at this low speed. i checked underneath but didn't see any problems with the blade hitting the sides. it did stall out when i ran into that grass, but started right back up at the lower speed. should i have it serviced or buy a new mower?
Make sure the bolt holding the mower blade hasn't loosened and check to be sure the blade is properly centered on the crankshaft end plate.
SOURCE: mower will not run in high speed idles at one
Your carbs main jet is most likely blocked. When the throttle goes off the idle jet to the main jet there isnt enough fuel flow and the engine stalls.
You need to removed the main jet and run a small piece of wire through the main jet to clear it. This is a good time to look at the inside of the float bowl to see if you have excessive water, rust or dirt accumulating that is a sign you should clean and drain the fuel tank and lines as well. The main jet is actually the bolt that holds the fuel bowl on the bottom of the carb! You need to look very close at the jet near the top of the threads to see the little whole there and clean it. A wire brush to clean off the threads and fine piece of wire strand to clean the hole will do the trick!
If you dont have a bowl type carb you will need to remove the carb from the fuel tank and locate and clean the inlet screen and main jet and then remove the fuel tank and clean it out too.
Good luck and be careful.
SOURCE: Lawnmower won't start. Was running then just
Hi kkeane20...
Make sure you are getting spark at the spark plug, to do this:
Remove your spark plug and check to be sure you are getting a bright blue spark at the spark plug.
You do this by grounding the plug on the head of the engine and pulling the crank rope...watching the plug for spark.
If you are getting a nice blue spark then skip A below and go to B.
A...If you do not get a nice blue spark then you may need to replace the electronic module.
Note: If you have to replace the module be sure to measure the position it is in, it is critical to starting.
Take a picture for later reassembly.
B...Also take some fine grit sandpaper (not emery) and lightly sand the flywheel where the magnet is located to clean any rust or corrosion from the magnet area.
Then follow the procedure below:
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Sounds like you have dirt/debris in your caburetor jets,fuel passages or a diaphgram that is becoming non-flexible.
Check/Clean/Replace your Air Filter, a dirty air filter can make your engine run to rich with fuel.
Note: ALWAYS USE COMPRESSED AIR TO CLEAN YOUR JETS AND PASSAGES, VERY IMPORTANT.
Note:Before you disassemble the carburetor:
Write down on a piece of paper and or take a picture of how the linkage attaches to your carburetor for later reference when you go to reinstall your carburetor.
Mark each piece with a awl, or some kind of sharp instrument that will make an alignment scratch before you disassemble the carburetor into separate pieces.
That way you will know which way it goes back together when you reassemble it.
Sometimes you can get by with priming the carburetor or by using a very small shot of starting fluid and letting it run a few times like that, and it will flush the gunk out of the jets,but most of the time you will need to rebuild the carburetor.
Be sure to check your fuel tank for water and dirt/debris, if there is water/debris then you need to clean your tank.
Check you fuel line/s condition...after a while they will degrade and need replacement.
Check/Clean/Replace your fuel filter if you have one.
When you remove your fuel lines from the carburetor be sure to make a drawing or take a picture of how the lines are connected to the carburetor.
Also a good time to take a picture for later reference for reassembly.
If the mower is over a couple of years old, then I recommend that you buy and install a new carburetor repair kit,because the diaphragm will get hard and that will cause it to be hard to crank.
The diaphgram may look good and flexible, but it can be deceiving and not act as a fuel pump as it should because it has become too hard and will cause hard starting,start and run and shut off, etc.
When you clean your carburetor, I recommend that you use a laquer thinner type cleaner to clean and dissolve the laquer build-up in the float and needle jet passages.
Be sure to remove all plastic and rubber parts before using the laquer thinner because it can dissolve the plastic parts and render them unuseable.
Be sure to use COMPRESSED AIR to blow out all the fuel and air passages.The higher air pressure is needed to blow some of the trash/debris from the fuel or air passages.
Be careful when blowing out the passages, because there are sometimes small rubber type seats in the bottom of some of the passages.
Keep in mind that the float (if you have one) for the carburetor must be level when you go to reassemble the carburetor or follow the instructions you get with the carburetor kit, or you could also ask the parts man that you get your kit from.
When you clean your carburetor and remove the jet screws, you will first need to lightly seat the jet screws.
But before you lightly seat the jet screws count the number of turns it takes to seat the jet screws from their original position.
Be sure to mark the turns down on a piece of paper.
That way when you put the jets back in, you know to lightly seat them first and then turn them back out to their original position before you started.
Once you have your carburetor cleaned/rebuilt that should solve your problem.
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SOURCE: My wife hit a stump
Hi ptcbob7...
Yes, she bent the crankshaft...very hard to get the bend out, most of the time a new engine is in line.
Being that your going to have to replace the motor anyway...I would take a large hammer and give it a good whack in the opposite direction of the bend, it may not take it all out, but it will take out some of the bend.
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SOURCE: the briggs and stratton 650
Hi and welcome to FixYa, I am Kelly.
What has happened to your engine is that the carb fuel float bowl had some minor sediment in the bottom of the bowl. When you ran out of fuel that sediment was drawn into the main fuel jet orifice in the threaded area of the bowl nut on the bottom of the carb. Since that is where the main fuel jet is located you now have a speck of debris blocking the jet orifice and it will not start.
You can prove this by adding just a splash of gas into the throat of the carb with the air cleaner removed. If it briefly runs... you have a fuel supply problem.
Remove the deul float bowl nut and the float bowl oaing close attention to how the gaskets stack up. Then clean out the bowl and spray some carb cleaner in the the very center portion of the threaded area to flush out the debris from the main fuel jet orifice. This usually clears the debris without having to take the carb off of the engine to remove the orifice for cleaning. Clean it and see if it starts.
Here is a breakdown of your carb. (expand)
http://www.partstree.com/parts/dispdiagimg.php?src=r&ilFN=D%3A%5CEMPARTweb_52%5CCatalog+Data%5CEMP_IMG%5CBRG%5Cimages%5C3728%5C0003.TIF&ilSC=10&ilIV=0&ilBR=0&ilIF=G&ilRE=8&ilSH=0&ilEG=0&ilRO=0&ilSC=24
Hiere is the actual parts listing and diagram:
http://www.partstree.com/parts/?lc=briggs_and_stratton&mn=126T02-0675-B2&dn=37280003
As far as using 2 stroke gas..... It will run just fine but..... is is definately not what your supposed to use. Most 2 stoke engines now use a 50 - 1 fuel mixture / 2.6 oz of oil per gallon. It will not do any permanent damage but... tell the guy that he will ONLY use UNLEADED fuel in the future.
Thanks for choosing FixYa,
Kelly
SOURCE: I hev a briggs & Stratton 5.25hp lawnmower and
I would need the engine numbers to tell ya what to do for sure. It sounds like the engine is too full on oil. Check oil levels carefully.That engine capacity is only 1 pint/16 to 20 oz's ALSO you friend may have cleaned under your deck and turned the mower with the aircleaner DOWN. That causes oil to flow from the crankcase into the air cleaner and muffler.That aircleaner is a dry paper and should not have any oil on it, If this is the case then the oil accumulated in the muffler will burn off in time. Oil soaked paper aircleaners will cause this engine not to start.IT CANT BREATH
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Sounds like there was a hidden suprise in the grass and you bent your crankshaft. Briggs motors can be straightened relatively easy, but requires dial indicators with a magnetic base. The engine won't run at full speed because the crank is in a bind. Have a nice day.
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