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Discussion Starter · #1 ·
hi everyone,
I'm new to this form so please go easy on me :)
I got an old "Murray" lawn tractor that was sitting outside for 3 years for free as a project. the engine looks perfect and has great compression. it has an electric start and the solenoid doesn't click at all.. so after ages of looking for all the safety switches (break, disengage blades, sit on seat) it still doesn't work... so I went to jump the terminals but they where rusty and it was in a tight spot so i took the starter wire off the terminal and put it straight to the battery terminal on the solenoid. there was sparks, a click and a hmmmm but no starting. then a little bit of what can only be described as smoke from the battery which got me worried. any ideas what could be wrong?
and its a hydrostatic automatic so it cant be push/tow started.
any advice will be worshipped
 

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Welcome irishlad! :)

Sounds like maybe the rain from setting outside killed both the solenoid and the starter. I assume you must be able to turn the engine by hand since you verified compression. So that leads me to think the starter has seized up. You might with a little luck be able to remove the starter and get it freed up and working provided there are no actual internal electrical shorts. One place to take a look for reference if you have not done so already is this page a B&S.

Electrical Schematic/Wiring Diagrams | Frequently Asked Questions | Customer Support | Briggs & Stratton

There are links to places on their webisite using model, type, and serial numbers you can pull up servicing manuals for the engine. This link found there shows the basic diagram of how the starting circuit works:

http://www.briggsandstratton.com/engines/support/frequently-asked-questions/Electrical%20schematic-wiring%20diagrams/~/media/B19B3742DFDA4270B639EEA3818B7018.ashx
 

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Discussion Starter · #3 ·
yesterday i took apart the starter, there was corrosion on the on the brushes so i sanded them until nice and clean, spent AGES trying to get it back together with those spring loaded brushes. i hook it up to a 12v battery charger and spins but not fast enough to lift the cog then the power CLICKS and stops working so im thinking its the power. im going to find some jumper cables and hook it up to the van and hopefully it spins properly.
in the mean time i was thinking of starting it using a drill and a 24mm wrench head, putting it on the bolt that's on the fan that spins, where the pull start would be placed
any advice with this?
 

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...in the mean time i was thinking of starting it using a drill and a 24mm wrench head, putting it on the bolt that's on the fan that spins, where the pull start would be placed
any advice with this?
Be VERY careful if you try that. If the engine does fire it can crank up to full rpm much faster then you can get the drill and socket pulled off the flywheel. Remember your drill will be maybe 300 rpm and the engine is headed toward 3000+ rpm at full throttle for choke. You can end up with your drill and arm tied in a knot before you realize what has happened. Also there is the chance of pre-ignition (kickback) if there is a timing problem. Plus you'll likely not be able to turn it fast enough with anything less then a 3/4" drill.

I think generally when you see guys doing that like with a racing car there is a special connector being used that only grabs in the direction of rotation. That way when the engine starts and it's speed exceeds that of the drill it forces the coupling apart. You still take a chance though on it kicking back even then. Ask the old timers that remember having to use crank starts on both cars and tractors about that. ;)

A safer alternative would be to rope start it if you can find a pulley cup (my terminology :D) like the old engines used.
 

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Discussion Starter · #5 ·
hmmmm i like your idea... i will have to go out and see if there is anyway of me doing this... so is it just wraping a lenght of rope around something where that bolt is..?
 

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Not just around the bolt area. It's one of those cup shaped things with a notch on one side to slip the knotted end of a rope through, like the sort of thing that grandpa had on the old reel mowers back in the day. When you get to the end of the rope, it slips our of the notch and releases you from any connection to the engine. Wish I had a better picture, but it's like this thing on top of this old outboard I have.

 

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Discussion Starter · #8 ·
ya after taking apart the starter and cleaning it up, i put the car battery straight to the starter and it did rotate but no all the way, it would turn the engine until it got to the compression stroke when it just stopped.... so i went to whip out the spark plug so i had to remove the exhaust.... when i did this petrol/ water ran out of the exhaust... i thought this was really odd, i continued to take out the spark plug and petrol GUSHED from the hole!!! i turned over the engine with the starter without the spark plug to empty the cylinder and petrol was fired across the shed and covered the wall!! im thinking it MUST have a carb problem aswell, even though i took it apart and cleaned it. so when i emptied the cylinder i put the spark plug in to see if the starter would turn her over now. but it still couldnt, but i can rotate it myself by hand on the top of the engine!!!
so now im thinking its a starter problem aswell as a carb problem :confused:
any suggestions??
 

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So the engine's been sitting around for a long time. It has fuel/water in the engine. When you remove the spark plug you get fuel spitting out the spark plug hole. The engine will turn when you take the spark plug out.

So it seems you have a flooded engine and when that happens the fuel gets all over the spark plug, gets it wet and then there is no spark.

Does the engine turn without the spark plug? It should NOT start but it should turn.

If so then you need to keep it on until you get as much of the fuel/water mixture out as possible. Then dry the spark plug and see if it will start.

You probably have a bad float under the carburetor and need to replace it.
 

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Discussion Starter · #10 ·
well actually I checked the spark on the plug after just blowing it dry and it had perfect spark. Ya the starter turns over the engine just fine with no plug in it but wont pass the power stroke with it in.... I will try having the van running while I do this to bring it up to 15v and hopefully be enough and maybe when its running for a while it will be easier started.
 

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With that much fuel in the cylinder be sure to check your oil. Chances are your oil with be full of gas too. :(
 
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