WON'T START!

[Sethro84 0]

OK guys!

So dad and I found an 88' 312-8 for a really good price, we pounced on it. Lady couldn't tell me much, she said it had sat for about a year and ran perfect when it was left. So it's been outside for at least a year and it won't even click at the turn of the key. <--- That's my problem.

What I do know is the motor DOES turn, the battery is fine, nothing LOOKs corroded through.

Starter? Ground? Anything?

Any help would be great guys, thanks in advance!

P.S. The motor is a 12HP Mag.

[rallysman 0]

Check the solenoid. It'll have a small wire, and 2 big wires. The big solenoid will "split" the connection between the battery and the starter. Short a wire from the positive side of the battery to the small wire on the solenoid. It should turn over or at least click. If it doesn't click, you either have a dead battery, bad ground, or dead solenoid.

[W9JAB 156]

:omg: That is good advice, But use a large gage wire or a big screwdriver to jump the large terminals to small of wire will smoke in your hand!

[oldandred 15]

Seth if i were you i would get a volt ohm meter to test with

[Sethro84 0]

Thanks for the help guys!

So this is what happened....

I got my muti-meter out and checked darn near everything. Seems ok, I took the solenoid off my and put it on another 312 we have, it clicked but seemed weak... Wouldn't turn the starter the whole way. So I put it BACK on my 312 and..... Nothing... No click. So now I think I may need to take the starter off and check that.

I also checked ALL the grounds, they seem to all be there. This whole situation is quite baffling, but thats part of the fun/challenge of it right!? As I said I assume that the starter is my next step; I know its rare that these are the issue but who knows.

Any further direction is greatly appreciated! And any pointers on removing the starter?

Thanks

[Prater 75]

Does your other 312 start? Take the starter solenoid from it and test it on the one that wont start to make sure its not bad. Are you also using the good battery form the one that starts, or using the old battery. If its the old one how did you determine it was good? Sometimes they have a bad cell and show 12 volts, but dont have any cranking amps.

[Irv 115]

Check and wiggle the fuse(s). Should be 2 of them right side in front of battery.

[Crazywheelhorseman 67]

Have you checked out the safety switches? sounds like your not even getting power to the small terminal.

[Prater 75]

did you bypass the safety switches?

[Buzz 502]

I took the solenoid off my and put it on another 312 we have, it clicked but seemed weak... Wouldn't turn the starter the whole way.

????????? You put the solenoid on that engine and it wouldn't turn it over? There is probably nothing wrong with your starter, if you used the same battery that's the problem. It tried to start the first one but had nothing left for the second one. If you used a different battery make sure that it is fully charged and try again.

[Just Piddling 0]

I agree it sounds like the battery, but since you have a meter, set to VDC and put the red lead on one of the small leads on the solenoid and the black to a bare metal part of the frame. Turn switch, if 0v check other small terminal. If niether show 12v then your problem is before the solenoid, ie... battery, safety switches, key switch.

Good Luck

[Sethro84 0]

All good ideas. I'll let you know how things go today.

[Duff 206]

Somewhere in all of this, I think we forgot to say.....

!

Glad to have you aboard, Seth!

Duff :omg:

[linen beige 14]

:omg:

All good advice, but nobody got to the point.

To do a direct test to determine if your starter will turn the engine with battery power you need to completely eliminate the rest of the starting circuit. The easiest way to do this is by taking a large guage wire (#8 minimum, #6 preferably) and connect the starter input directly to a known good battery. You also need to insure that the starter is well grounded.

Connect one end of the large wire to the battery and touch the other end to the starter input terminal. If you have a good circuit you will get sparks just as the wire touches the terminal, but if the starter is good it will turn and the drive will engage. If it doesn't turn and engage the drive the starter needs work. This will not start the engine since it sends no power to the ignition circuit.

If the starter tests good THEN go through the remaining circuits to find the weak link.

[Sethro84 0]

GOOD NEWS!! I tested the starter the direct way, and it jumped right away and turned over! So now I'm back to grounds, and somewhere in between the starter and ignition... oy

[Just Piddling 0]

With the suspect battery or a different one?

[kpinnc 11,877]

Seth, check and see if your engine has a low oil switch, and check the clutch pedal switch as well. My 310 had a bad low oil switch, and it did exactly what you're talking about.

The switch is just a float that is inserted into the back side of the oil pan. When the oil level is up where it should be, the switch is closed and will allow the interlock circuit to be completed.

Good luck!

Kevin

[dgjks6 6]

I am going with the PTO safety switch. I have had 2 312's and this was the problem. There is a spring loaded wire that has to touch for the ingnition to work when the PTO is off.

[Sethro84 0]

Thanks guys, been kinda busy past few days. but I'll be checking those things this afternoon!

[Sethro84 0]

Ok.. so maybe a dumb question... But!

What do the test lights tell me?! What's WORKING? Or NOT WORKING?

If the lights is on do I need to check that thing, or check it if the light is off?!

That might send me in the right direction!! Thanks guys!

[Just Piddling 0]

If you have a digital multi-meter, forget the test light it can be misleading.

Check the solenoid to see if you have voltage to the coil. If not, set the meter to Vdc, place one lead on B+ and one on the solenoid. When you try to crank you should see 0v if good. Testing this way shows a voltage drop. If you read 12v there is an open somewhere. Then follow the coil wire back to a junction or switch and move the test lead from the coil to that point. Keep checking back till you find the open circuit. If you read >1 and <12 you have a bad connection or partially broken wire.

Voltage drop is also the best way to test switches because this test the current carrying ability of the switch.

I don't know if I explained this well enough. If not PM me and I will give more detail.

[Sethro84 0]

Thanks Chris

I'd still like to know what they indicate!

[Just Piddling 0]

I'm sorry, I thought you were talking about an actual test light.

I don't know what lights your model has. If you are trying to crank it they may all be lit, kinda like a car. Just a guess.

[travisg84 1]

When you turn the key to start the lights where there are issues should light up if you flip the test switch they should all light but the oil will blink. Of couse when I bought mine all the lights were burnt out. I have heard ithe circuit board gos bad they can keep the mower from running. I think I paid like $115 for a new one.

[dgjks6 6]

If you flip the test switch all the lights should go on (except the oil - it will blink as stated above) to tell that all of the safety switches are working.

When you turn the key - no lights should be on. If one is on then that is the problem. For example, if it is the PTO preventing the starting that light will go on when you turn the key.