Kohler Magnum 16 popping spluttering.

[Robins 26]

Hi all,

Been trying to get my Kohler Magnum 16 engine running. It starts really easy hot or cold, tick over is fine and very smooth hot or cold, but, when increasing the revs it pops and splutters and does increase but still popping a bit, when trying to drive it just goes flat and gutless, a small bit of choke does help but still wont rev nice, will drive but not well. 

The pump is mechanical and came off my K301 12hp.

Carb has been professionally rebuilt and been tested on a rebuilt engine so came back set, I have re-adjusted it slightly but doesn't make much of a difference.

I've not had the engine running before myself so can't say i've done anything to it that would have made a difference, all i've been told is it did run years ago and was removed when the starter motor broke.

Don't know if it's normal or not but when throttle lever is full, with engine off, it opens all the way round on the carb. When engine running and throttle on full it only goes half way and splutters.

Ive set the valve clearance and ignition module as per the book. 

Any help gratefully appreciated.

 

cheers, Daniel

[oldredrider 2,547]

It may have a sheared key on the flywheel causing it to be slightly out of time.

[WH nut 553]

Sounds like lack of fuel, check your fuel supply from tank to carb.

[Robins 26]

Thanks, 

It starts and ticks over really well and smooth so reluctant to go broken key way, i was assured it was a good engine.

I've got a few things to check and change so will report back on those later.

 

cheers,

[boovuc 1,090]

I know you stated above that the carb was gone over and rebuilt professionally and tested but intermittent goofy performance is possible with a wallowed throttle shaft. (Runs good for awhile then is all over the place and especially on full throttle operation and changes of the season).

I believe it too is most likely a fuel delivery problem but I would check for any "play" in the throttle shaft running through that carb just to eliminate it as a possible issue. Look for play north, south, east and west! I saw a few of these issues as reason enough that people get rid of their tractors when a shop or dealership says the carb has been rebuilt and is good!

[Forest Road 594]

How old are your fuel lines? They do break down over time. Also install an inexpensive clear filter.

If that doesn't do it pull the carb. Theres a tab on the float. It can be slightly bent up it down. This will affect performance while driving typically problematic on a slope. I had a perfectly good M-12 give me problems all of a sudden. Bending that tab made a world of difference.

[Robins 26]

I've had a tinker today and made some progress  Tried a few things with no change, but fitted an electric Facet pump and things have improved hugely! I guess my want for a mechanical pump were the issue, also old fuel, it seems my cans have been moved in the shed (shared shed) so not sure how old the fuel is i have put in! This being the case i'm getting new fuel, pipes and replacement filter Monday and will see if i can get this running perfect Not sure what electric pumps are ment to be used but if the Facet one works i'll have to make a bracket up. 

Thanks all for your help, i'll let you know how the new fuel and lines go in the week.

Thanks, Daniel

[WH nut 553]

Sounds like you are well on your way

[Forest Road 594]

Thats great news!! I have a Facet pump on the workbench waiting for installation. Once I finish my k-341 build I'll install it. I'd be curious to see how you mount it.

Back to fuel. I keep a piece of cardboard on my fuel cans. Anytime I fill I mark date, Octane, & additives. Having a vacation house has forced me to be OCD with my fuel.

[Robins 26]

Hi all, It's been a while but remembered i need to update for help of future readers.

 

The Facet electric pump helped with fuel delivery, obviously a old tired mechanical K series pump is not up to delivering enough fuel to a Magnum 16. But did not solve the problem.

New fuel, pipes and in-line filter made no difference.

Took the fuel bowl off and found some debris so cleaned it, checked all settings again.

Found the Governor adjustment out and was not opening the throttle enough, helped with settling things down but still wont run. 

Tried a different spark plug (wrong type) and made running bad all over then wouldn't start at all so refitted the correct plug.

 

So gave up for a couple months as my trusty 312-8 did everything i needed.

 

Decided to have another go and get my Electro going or i'd change the engine back to the worn out K-301.

There must have been some debris still in the pump after i changed the fuel and lines, so cleared the fuel bowl again and had life once more. 

Starting easily and tick over lovely, as the revs increase it would pop and fart and die off.

Decided to test the spark plug. This was the problem, on idle the spark was fine, as the revs increased the spark got more sporadic and eventually stooped momentarily letting the revs die off or stop the engine. A new plug and the engine ran lovely, letting me set the mixtures perfectly.

 

Now the engine idles like a stationary engine at a steam rally, slow and smooth. Higher revs are nice and quiet (thanks to the stack pipe) and smooth.

 

So, just because the spark plug is new, don't rule out it being a duff one!

[pfrederi 17,129]

Hi all, It's been a while but remembered i need to update for help of future readers.

 

The Facet electric pump helped with fuel delivery, obviously a old tired mechanical K series pump is not up to delivering enough fuel to a Magnum 16. But did not solve the problem.

New fuel, pipes and in-line filter made no difference.

Took the fuel bowl off and found some debris so cleaned it, checked all settings again.

Found the Governor adjustment out and was not opening the throttle enough, helped with settling things down but still wont run. 

Tried a different spark plug (wrong type) and made running bad all over then wouldn't start at all so refitted the correct plug.

 

So gave up for a couple months as my trusty 312-8 did everything i needed.

 

Decided to have another go and get my Electro going or i'd change the engine back to the worn out K-301.

There must have been some debris still in the pump after i changed the fuel and lines, so cleared the fuel bowl again and had life once more. 

Starting easily and tick over lovely, as the revs increase it would pop and fart and die off.

Decided to test the spark plug. This was the problem, on idle the spark was fine, as the revs increased the spark got more sporadic and eventually stooped momentarily letting the revs die off or stop the engine. A new plug and the engine ran lovely, letting me set the mixtures perfectly.

 

Now the engine idles like a stationary engine at a steam rally, slow and smooth. Higher revs are nice and quiet (thanks to the stack pipe) and smooth.

 

So, just because the spark plug is new, don't rule out it being a duff one!

What brand of spark plug was the culprit.  i have had two instances of Champions that would spark when tested outside the engine but failed to fire under pressure in the cylinder.

[Don1977 604]

Make sure you have a non-resister plug. Resister plugs require higher voltage to fire them.