247.370370 190cc Platinum Series Push Mower Will Not Start

Yes a hissing sound is a bad valve ...... Or one not seating well...... Can you borrow a leak down tester ???

That will tell the story all the way......

Sorry for the late response, I had to go pull a load of water melons from Sugar Town La. this afternoon....... Just got back from selling a few at Tractor Supply here in town ...............


Make sure the key didn't shear again...... That happened to me before..............

Let us know Mon Ami ~!~!
 
Boudreaux In Eunice La. said:
Yes a hissing sound is a bad valve ...... Or one not seating well...... Can you borrow a leak down tester ???

That will tell the story all the way......

Sorry for the late response, I had to go pull a load of water melons from Sugar Town La. this afternoon....... Just got back from selling a few at Tractor Supply here in town ...............


Make sure the key didn't shear again...... That happened to me before..............

Let us know Mon Ami ~!~!
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Boudreaux, the new key is still okay so I tore into it. I'm wondering if the intake wasn't seating properly like you said.
I could not spin either one by using my thumb. Do you know the valve clearance on this series motor? I think I found the info on Briggs and Stratton website, .005/.007 Intake .007/.009 Exhaust if this is right???

It's a 128MO2-0952-F1

I measured the gap at around .005 on each one before removing the valves. The intake was suprisingly galled looking on the stem, but polished up easily. The faces on both were dirty. Of course I cannot find my hand lapper... The exhaust has some play, but I have seen worse. I'll order a head gasket and lap the valves. I hope this gets it!
 
Okay, first head gasket arrived and FedEX decided that fragile warnings on packages don't apply to them. So, the first gasket was folded in two and ruined. In the meantime I rechecked the valves, measured the new lapped seats at approximately .055 width on both intake and exhaust.

The exhaust guide is worn and should probably be replaced, but aghhhh, I've got briggs and strattons laying around here that are severly worn and start first pull. THIS MAKES NO SENSE!

Time for conspiracy theories. Is there anyway in hell that the cam has magically moved in relationship to the rest of the moving parts of this motor? NOTHING else makes sense. Is there anyway that the gears have moved??!! Does this cam have plastic gears? (Okay, in asking that question I looked on the Internet and I just found the problem with this motor) The cam is freekin plastic. Anyone know what part number I would need to replace this with an ALL METAL CAM?

Thanks.
 
The cam is freekin plastic.
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Is that the problem?
Plastic cams have been around for a couple decades now, so...nothing new here.
Other than the Honda OHC (GVC 190 etc.) series of engines, I have not seen a plastic camshaft fail.
Have never seen a B&S mill with a failed camshaft.
 
Russ2251 said:
Is that the problem?
Plastic cams have been around for a couple decades now, so...nothing new here.
Other than the Honda OHC (GVC 190 etc.) series of engines, I have not seen a plastic camshaft fail.
Have never seen a B&S mill with a failed camshaft.
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Russ, the motor will not start. The keyway was sheared. I have now been through everything except the internals.

If it was a V8 I would check to make sure the distributor wasn't 180 out, so I started looking on the net. As of right now I found the exact lawn mower and his problem turned out to be a spun timing gear on the camshaft. Another had two lobes lined up when it twisted the plastic camshaft. Yet another had the gear spin in relation to the lobes. The more videos I watch, the more the plastic camshaft looks like the problem. I don't know much about these little motors as far as interchagable parts.

I don't know if it is the cam either, but I am about to find out. Do you know what cam part number will work?
 
Boudreaux In Eunice La. said:
You need to stick with the 005 and 008 on those valves. and yes those cams gears can turn when hitting something hard... They are epoxied together............
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Boudreaux, I did. I think you misread my post above. I did slightly clearance both valves as they were tight at .005

Do you know an interchange to get away from that style camshaft?
 
I figured I should respond back so if anyone is interesed in the future.

When I first looked inside, the cam looked good...it wasn't. While rotating the crankshaft by hand the cam lobes were not where they should be when opening the valves. I compared the replacement ebay $1.50 camshaft and it became obvious that the thin metal bracket pinned just under the gear was also suspiciously bent.

I installed the used camshaft, replaced the case gasket, and put a new bottom crankshaft seal in and reassembled everything.

My dad was over at the house and I tossed him the camshaft. I asked him, "What's wrong with that?" He said, "It's plastic" and tossed it back.

It ran first pull.

Thanks for everyone's input!
 
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