Engine wont fire. Has spark...help!!

[nickj21 20]

Hello. Got myself in a little trouble....seems this horse keeps kicking me in the chest. I had a wiring problem.  i got that fixed. Now the engine just keeps cranking and wont fire. Has spark. Its getting fuel....just wont fire. Any ideas would be greatly appreciated! Thanks in advance!!

[KC9KAS 4,743]

Are you positive that the wiring repair is correct?

Do you have the correct ignition switch for your machine?

New spark plug? Points clean and gapped correctly?

Have you looked at the manuals for your (un-named) tractor?

[rmaynard 15,913]

So it has spark, and you say it is getting fuel, so the only other thing that is needed is compression. I doubt that is the problem, I am inclined to guess it is one of the other two.

 

My questions would be how did you check for spark? Did you pull the plug, ground it and look for spark at the tip while cranking?

How do you know it getting fuel? Was the plug wet with gas when you pulled the plug out?

 

Could be that it is just flooded.

[the_nite_owl 15]

I have a 16HP Kohler K341 doing the same thing.  Got spark, got fuel and air but wont fire.
  I have not figured out my issue yet but here are some things to consider.  If your valve timing is off the spark could be occurring at the wrong time missing the compression stroke.  The valves could be opening or failing to close causing the compression to be too low for ignition.  Likewise the valves could be sticking causing those issues rather than timing being off.

The fuel might be flowing too freely and fouling the plug preventing ignition or drizzling in rather than being pulled in as vapor.

You could have a vacuum leak at the head, oil pan or one of the carburetor seals.

If your engine has a dump valve it might be stuck causing the compression to stay low.  If the engine does have a dump valve you might not be getting enough RPM to close the valve and get compression for it to fire.

All of that said, I still dont know what is going on with my K341.  Cranks over readily, valves are moving nicely but the fuel will just come drizzling out.  Could be carb or fuel pump issue.  I'm just tired.

 

[Horse46 519]

11 hours ago, nickj21 said:

Hello. Got myself in a little trouble....seems this horse keeps kicking me in the chest. I had a wiring problem.  i got that fixed. Now the engine just keeps cranking and wont fire. Has spark. Its getting fuel....just wont fire. Any ideas would be greatly appreciated! Thanks in advance!!

I've had a little trouble with this myself and it can be frustrating if you aren't really sure what your doing (like me)

Here are a few things I tried, 1st eliminate the tank, remove the cap first just incase it is causing a vacuum, then get a can of fuel above the motor to eliminate the tank, could be dirt blocking the valve in the tank of the filter? take the bowl off the carb while your at it, I had a fair bit of dirt in mine. 2nd Static time the points, use the search function to find this, if you have done all of the above it should at least start. 3rd set the carb back to factory setting, this in the manual as well. If all that doesn't work I would check the safety switches. As for the valves I've only heard that they can cause "hard to re start" if the exhaust valve is to tight. Have a look on you tube for valve setting, KrazyHorse is the guy I found who explained it real simple (I needed that) 

I got all this info from the very clever peeps on here, and I got mine going in the end.

27 minutes ago, the_nite_owl said:

I have a 16HP Kohler K341 doing the same thing.  Got spark, got fuel and air but wont fire.
  I have not figured out my issue yet but here are some things to consider.  If your valve timing is off the spark could be occurring at the wrong time missing the compression stroke.  The valves could be opening or failing to close causing the compression to be too low for ignition.  Likewise the valves could be sticking causing those issues rather than timing being off.

The fuel might be flowing too freely and fouling the plug preventing ignition or drizzling in rather than being pulled in as vapor.

You could have a vacuum leak at the head, oil pan or one of the carburetor seals.

If your engine has a dump valve it might be stuck causing the compression to stay low.  If the engine does have a dump valve you might not be getting enough RPM to close the valve and get compression for it to fire.

All of that said, I still dont know what is going on with my K341.  Cranks over readily, valves are moving nicely but the fuel will just come drizzling out.  Could be carb or fuel pump issue.  I'm just tired.

 

Hey night owl, don't give up, been there felt that, try what I've suggested to nickj21, I would start with the cap and go from there.

[the_nite_owl 15]

Forgot to suggest, try spraying a bit of starting fluid into the carb when you crank it over.  If it will not fire with the starting fluid then the problem is likely spark or compression rather than fuel.

Horse46, thanks for the tips.  I have been through it all.  without luck so far.  I may have to buy a leak down tester to check the compression cause there is no way I can spin this engine over fast enough to get past the dump valve and get a reading from a regular compression tester.

 

Oh, rmaynard, also check if your engine has a crank case breather.  If it is clogged you will have a lot of issues.

[nickj21 20]

10 hours ago, rmaynard said:

So it has spark, and you say it is getting fuel, so the only other thing that is needed is compression. I doubt that is the problem, I am inclined to guess it is one of the other two.

 

My questions would be how did you check for spark? Did you pull the plug, ground it and look for spark at the tip while cranking?

How do you know it getting fuel? Was the plug wet with gas when you pulled the plug out?

 

Could be that it is just flooded.

Yes i grounded the plug and it sparked. And i pulled the hose from the carb and cranked it and it poured out. And yes there was gas on the plug. My only other thought is bad gas...it has everything needed for it to start it just isnt...

[gwest_ca-(File Mod) 11,243]

Have a new spark plug you can try? Plugs will fire out of the engine but not under compression.

 

Garry

[ohiofarmer 3,333]

9 hours ago, gwest_ca said:

Have a new spark plug you can try? Plugs will fire out of the engine but not under compression.

 

Garry

Absolutely. Spark checkers are a better test than grounding against the engine block. My favorite spark checker happens to be a timing light. You can see whether or not it is sparking under compression, and also see the quality of the spark and detect an intermittent miss  The intermittent miss might not apply at all to single cylinder engines, but is really helpful at high RPM on multi cylinder power plants. . Harbor freight has two price points for timing lights and the cheaper one will do just fine.

 

Here is a spark tester that you can make. Even with the electrode bent straight, you should be able to get a fat spark if all is well.

The link the illustration comes from is here. Lots of good stuff on leak down testing and compression as well. Although written for [vintage] motorcycles, much of the info applies to our stuff as well.

http://www.dansmc.com/troubleshooting2.htm

Good luck

[jeff lary 173]

So opening up the ground strap like that takes the place of the higher atmospheric pressures found inside the cylinder? (ie) making the spark work the same amount as if it were in the engine. At least I think that's how it works right?, the extra stress caused by the extended ground strap it is comparatively the same amount of electricity needed as if the plug were in the cylinder?

[ohiofarmer 3,333]

 Yes, Jeff, That is what the author in dansmc stated somewhere in his repair course.

[Geers65 0]

I have a kohler 341s that had a blown head gasket. I put a new one on and got it fired up. It purred like kitten, then we had a hard rain and wind storm that night which blew my tarp off, and i haven't been able to get it started again. All it does is kick back on the starter and back fire through the carb. I have a new carb on it and new points. I Can't figure this one out

[pfrederi 18,324]

Spark plug wire got wet??????

[953 nut 57,861]

2 hours ago, Geers65 said:

new points.

Is the points cover tight and waterproof. Double check the points gap, the points also set your ignition timing. Also, be sure you re-torque the head bolts now that you have operated the engine.