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B&S 6.75hp mower engine SCREECH noise


ahenchmen's Avatar
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12-17-09, 07:55 PM   #1  
B&S 6.75hp mower engine SCREECH noise

Below are the specs of mower and engine:

21" Troybilt (model 12A-466M011) with B&S 6.75hp engine.

The mower makes a very loud screech noise when the pull chord is pulled quickly or when it runs and I'm having trouble tracking it down.

History: I bought the mower used and the person I got if from said they were using it one day and it started making this screeching noise. She never started it again after that witch was 3-6 mo ago. Mower is about 3 years old I think.

The mower is only a few years old with what appears to be regular/light use. The engine will spin and feels fine but as soon as you try to pull fast you get a screech noise. I started it for a second with starter fluid and it was an extremely loud screech noise. I changed the pull chord, not change. I confirmed the flywheel break is not touching either. The cable to disengage the break works just fine with the top shroud off. The noise sound very much like metal on metal.

Now I've run out of ideas. I don't see anything broken/damaged. No exterior oil leaks on the outside of the engine, just your normal dust grass build up.

My only thought left is that as the engine spins faster something is being flung outward from the centrifugal force and rubbing up against another part.
Any ideas?

 
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12-17-09, 08:49 PM   #2  
This mower is either a 2007 or 2008 model. I see that it is self-propelled. The screeching is most likely the drive belt. Look underneath and remove ALL grass build-up. Pay close attention to the area around the belt pulley, which is just above the blade. Grass build-up will cause the belt to "get wet" from the grass and slip on the pullies.

 
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12-17-09, 08:54 PM   #3  
Does this engine have the starter clutch with the balls in it thats fastened to the crank??? If so,,remove it & clean the crank & VERY lightly lube it,, When you get it back together,, put 2~3 drops of oil in the hole in the top of it,,, If you have a different style starter,,sorry, just ignore this post,,, Roger

 
ahenchmen's Avatar
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12-17-09, 09:11 PM   #4  
Hey now you might be on to something.... I did notice that the self propel wheels didn't turn when I had them engaged while trying to pull start the mower.

I just pulled off the plastic front cover over the transmission and looks like the belt has flipped. Best I can tell the transmission spins when engaged. The belt however I can't pull CW/CCW, looks to be stuck around the engine shaft area.

If I find anything other than a bad/twisted belt I'll post otherwise looks like the problem area has been narrowed down to the belt / shaft area.

Many thanks...Beer 4U2

 
ahenchmen's Avatar
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12-18-09, 07:58 PM   #5  
Problem solved... A slipped belt. Wouldn't have been my first guess.

WOW. Sure was noisy!!!

Thanks to all for the quick helpful ideas...

 
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