Briggs and Strat 4 hp hard pull start

giuseppe105

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Joined
Jun 4, 2012
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Well I got another engine because I broke the last one. This one is old and has been sitting for a long time. It wasn't attached to a deck. So I put it on my old deck cleaned the carb and the gas tank. When i pull the starter cord Its extremely hard. I take the spark plug out, and now its easy.

questions:
1. Is it because of where the piston is when i put the spark plug in?
2. Is it because the gas and exhaust valves are clogged not allowing air to pass.

On a side note. I am getting sparks at the back of the engine where the copper wire attaches to the thing that touches the flywheel. This is probably causing my spark plug to not spark or spark weakly. But that's probably just because I installed the magneto wrong.
 

pugaltitude

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Jan 11, 2012
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Well I got another engine because I broke the last one. This one is old and has been sitting for a long time. It wasn't attached to a deck. So I put it on my old deck cleaned the carb and the gas tank. When i pull the starter cord Its extremely hard. I take the spark plug out, and now its easy.

questions:
1. Is it because of where the piston is when i put the spark plug in?
2. Is it because the gas and exhaust valves are clogged not allowing air to pass.

On a side note. I am getting sparks at the back of the engine where the copper wire attaches to the thing that touches the flywheel. This is probably causing my spark plug to not spark or spark weakly. But that's probably just because I installed the magneto wrong.

Does your mower have an OPC lever?
The "thing" at the back of the engine is probably the engine brake.
Newer vertical engines have a brake as they need to stop turning when you turn off engine within about 3 - 4 secs.
If you dont have an OPC lever remove the brake and then wire to coil using the throttle control which should have a micro type switch to switch engine off.
 

giuseppe105

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Jun 4, 2012
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I don't know what an OPC is.

but its auto throttle and there is no choke in the carb.

The only thing on this mower is the thing on the handle that controls the engine brake.

EDIT:
the opc lever is the thing i pull down to disengage the brake?

EDIT:
Does the Short at the brake with the wire connected to the magneto have anything to do with a hard start?
I have 2 of this exact same engine I have a second flywheel and a second magneto.

By hard start I mean it wont start because there is too much pressure build up in the combustion chamber.

I believe that something might have gotten stuck or crawled up into the valves that control the gases in the combustion chamber.
Or one of the gears that controls those valves is missing or broken.
 
Last edited:

giuseppe105

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Jun 4, 2012
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Just an idea... Could it be impossible to start this lawnmower because I didn't install the blade yet?
Would the blade provide enough force to get the engine to pass that high pressure easier.
 

giuseppe105

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Jun 4, 2012
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Ok guys... I put the blade on and it pulls fine now. I was lazy and i put the blade on a broken blade adapter because i didn't want to take the rusty thing off.. ill replace it with my good one later. I put the whole mower together and it runs great. that engine was sitting on the floor for who knows how many years.

There is 1 slight concern I have. My PCV is very loose. I turned it and it tightened but then i couldn't get the plastic thing to connect to the carb.

Also the steel mesh that goes around the flywheel was not attached to the flywheel anymore so I cut it off... If I didn't it would have broken the flywheel when I turned the lawnmower on.
 
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