# Mtd gold. 46" will crank, but not start



## Howjame (May 20, 2014)

Hi all, first run of the season, new oil, gas, belts. Ran fine until I caught a tarp up in my blades. The machine quit instantly, after I removed the obstruction, I started it, drove to my garage to check for any further damage, found nothing, and all seemed to freely move. But now it won't start! I checked for fuel, spark, combustion, checked fuse, made sure all wiring seems fine, I let it cool down for a few hours, still nothing, it cranks, but won't fire! Any help is greatly appreciated, I can change oil and maintain this thing, but I'm no good with this type of troubleshooting! 
Thanks, james


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## jhngardner367 (Apr 5, 2011)

It may only have flooded the plugs.
Remove the sparkplug(s),and see if it still has spark.When you pull them out,see if they appear wet.


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## Howjame (May 20, 2014)

There is spark, and not wet, I read on theses forums, sometimes these mtds have a hard time restarting after its been running a while. So I let it cool down, still nothing. I'm wondering if I accidentally tampered with a safety, is there a way to override all electric safeties to see if that's the problem?


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## BigT (Sep 15, 2014)

You've got spark, so give it a shot of ether down the carb and see if it'll start. Maybe you're not getting gas for some reason??

You may have sheared a flywheel key when you hit the tarp. Moved the flywheel just enough to throw the timing off where it won't start..


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## Fredneck (May 25, 2012)

if you've got spark, i doubt any safety switches are the problem.


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## jhngardner367 (Apr 5, 2011)

As BigT said,try fuel or ether in the carb,to see if it starts.
Since it started up,after the stall ,I would check to see if it is still getting fuel into the carb.Disconnect the fuel line at the carb,and see if it runs out.
Check the filter,if equipped,and also the carb solenoid(if equipped).


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## Howjame (May 20, 2014)

Ok, so I put fuel in carb and the machine popped, but no start ( like a backfire) I pulled the carb and fuel was flowing, I also checked the fuel line and it flows, but still no start. Someone mentioned timing, but I did drive it back to the garage after I hit the obstruction... Is there a chance my spark plug is just too weak? Also my father mentioned about the gap on the plug being to big, does anyone know what the gap should be? All of this has been helpful, thanks so much! James


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## HarveyW (Sep 15, 2014)

Your spark should be bluish-white, capable of jumping at least 1/4". A yellowish spark is often not good enough. 

If no luck, pull the flywheel cover and inspect the flywheel key for any evidence of shift (sheared or partially sheared key). It doesn't take much of a shift to screw up your timing.


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## Howjame (May 20, 2014)

Great! Thanks, The fly wheel (excuse my ignorance) is that the plastic cover then the fly wheel? I have inspected that all seems fine, should it spin freely by hand? It does, I see no sheared teeth... The spark does go 1/4"... This is really getting to be! I'm watching my lawn grow every hr this things busted! 


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## HarveyW (Sep 15, 2014)

The "key" you are looking for is in a groove on the crankshaft/flywheel shaft. Holds the flywheel in position on crankshaft for correct timing. But the "key" is made to be shearable if you hit something, so you don't damage the crankshaft.


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## jhngardner367 (Apr 5, 2011)

Spark plug gap is 0.035",for OHV,and 0.030 for flat head engines.
Even a small indentation on the fly wheel key,can change the timing enough to cause this.
I have to agree with HarveyW,since the engine stopped so quickly,it is likely that the key is the problem.


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## Howjame (May 20, 2014)

Even if I drove it back to the garage? Like a delay in the damage? I have not had time to remove fly wheel, but will tomorrow after work... 


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## jhngardner367 (Apr 5, 2011)

Yes,even though it started back up,and ran to the garage,it could have already sheared,a bit. Then,when the engine shut down,it moved a bit more,and won't start.
I had this happen on a customer's tractor,and after pulling the flywheel,we could see that the key was marked. Changed the key,and it ran great.
If you take off the flywheel,and see a mark on the key,..change it. It only takes a mark deep enough to feel with a fingernail!


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## Howjame (May 20, 2014)

Great, will try and let you know how all goes



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## jhngardner367 (Apr 5, 2011)

Usually it will be something sinmple,unless the unit was really abused.

I owned and operated a small engine repair shop,for 15 yrs,but,the other day I got caught.

I had been working with my Bolens,and shut it down for lunch.
Went back out,and it wouldn't start.
After looking it over for nearly an hour, I realized .....I hadn't turned the fuel on !


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## Howjame (May 20, 2014)

Ok, so fly wheel cover is off, and as suspected, the key in the crank shaft has shifted ever so slightly! I'm hopeful this is my problem, but how do I get the flywheel off? After I pull the single bolt in the middle out should it pop off? I'm worried the key is causing tension to hard to remove? Can I try to hammer it back in place? I'm afraid to pry too hard off the moter...


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## jhngardner367 (Apr 5, 2011)

Howjame, what engine model is this? There should be some #s on the shroud or the valve cover.
There should be 2 threaded holes in the flywheel.
These are for a puller. DO NOT HAMMER on the fly wheel,or the crank shaft ! The puller you need is basically a block of steel ,with holes for the bolts to go through(no threads). 
The center of the puller pushes down on the crankshaft,as the bolts pull up on the fly wheel, to pop it off.
Once the new key is in,simply put the flywheel on the shaft,and tighten to 80 ft lbs.


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## Howjame (May 20, 2014)

It's a Koehler model sv600s, I see the holes, will look into a puller and a torque wrench


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## jhngardner367 (Apr 5, 2011)

In that case, tighten the flywheel bolt to 100 ft lbs .
Also, you may not need a puller.
Place a prybar under the flywheel,and GENTLY lift up. If it doesn't pop loose.Screw the bolt into the crank shaft,without the washer, and leave 1/2" of space,and pry up,while tapping on the bolt,with a ball peen hammer.
Don't smack it too hard,...just enough to pop it loose.
Be careful not to damage the electricals , under the flywheel,with the pry bar.


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## Howjame (May 20, 2014)

Great I will try those and let you know how it goes!


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## Howjame (May 20, 2014)

I think I'm running out of options! I got the crankshaft off, aligned and back on, reassembled everything, but the lawn tractor still won't fire! If I pull the plug after cranking it, having tried choke on and off, the plug is dry, should it not be wet with fuel? If so how do I repair that? There is fuel running into the carb 100% spark+fuel+combustion, something's not right here... Any help would be greatly appreciated! Even a phone call would be a great help if you want to hear the lawn tractor turn over


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## Howjame (May 20, 2014)

I have also just noticed that one of my belts that drive the motor is extremely loose and worn out with a nick in it, is it possible that it won't? 


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## jhngardner367 (Apr 5, 2011)

The belts don't drive the motor,....the motor drives the belts .
There may be fuel TO the carb,but it may not be getting through the carb !
If it has a fuel solenoid,on the carb,check to make sure it is working.


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