30 horse Kohler Popping

[dnalley]

I have a Cooks MP 32 with a Kohler 30 hp engine.  Had to replace the fuel line and filter and since then, when I'm sawing, it seems to spit and pop....loud popping, like it's backfiring or something.  I checked the plugs and they seem to me to be wet and dark, like maybe it's running too rich.  Never had a problem till now...still runs great but I hope I'm not damaging the engine.  At idle just pops every now and then, but under load it's worse.  Any ideas what has happened ???  Thought maybe someone else might have already solved this and would be willing to share your thoughts.  Many thanks.  Dwight

[Larry]

I can't help with your engine problem but can point to a place to get a free service manual.

http://www.kohlerengines.com/manuals/landing.htm

I was really impressed with the manual I printed out for my engine.  It had a step by step trouble shooting guide.  Not for sure if it is available for all engines but might be worth checking out.

[dnalley]

Many thanks, Larry.  I had no clue I could find this info to download.  Doesn't mean I can solve the problem but it won't be because I don't have the info to troubleshoot.  Again, thanks so much for the heads-up and link   Dwight

[bushhog920]

check fuel flow, had a lawnmower do the same thing when the fuel tank valve was  half open.

[sigidi]

Dwight I run a 30hp Kohler on my Lucas and haven't had any trouble with it 'popping' but from what you say it's something to do with that replaced fuel line and/or filter, maybe you got a bit of air lock in it? maybe it had some moisture in the filter? easiest way out of it  I see is to swap the parts and see what happens...?

[pyrocasto]

Could be an electrical problem too. If your points have a bit of corrosion on them you will hit and miss fire, which will also cause black and wet plugs.

[ladylake]

I'd think electrical also, if it was fuel supply it might pop as it ran out but would want to die under heavy load.  Check to make sure you didn't wiggle a wire loose when you were working on it staring with the spark plug and coil wires.  Steve

[Hilltop366]

Perhaps the changing of the line & filter caused some junk to get caught in the float valve this could cause the flooding, If the fuel system is gravity feed or has a fuel pump but will siphon it will cause the engine to flood or fill up with gas when not in use so you should check your oil to see if there is a rise in the level.

Also if the engine has a electric fuel shut off valve on the float bowl check to see if it is working properly. This should cause a lean running engine which doesn't sound like your problem but I thought it was worth mentioning.

[dnalley]

Thanks for all the helpful replies folks.  Now i've got to do some troubleshooting with more ideas than I could come up with ;).  If I get it straightened out I'll surely post the fix, in case it just might help someone else.  They say two heads (or more) are better than one, and in my case that is so true.        Dwight

[pa_of_6]

I would also check all the fuel line connections, the fuel hose, and the body of the fuel fitler or cracks or air leaks.

It could be possible that you are getting air into the fuel line.

It may only happen at certian positions of the mill head.

And, even though everything is new, it still may be cracked.

Be sure that all your hose clamps are tight.


It may also be possible that there was some junk in the new fuel line that has now migrated to your carb.

[laffs]

sounds like  water in your fuel. i get some now and then and havve to drain the tank change the filter. ive gotten in the habbit of putting in a shot of dry gas every time i fill up, seems to work.

[JV]

I don't want to be a wet blanket but my 28 hp would backfire and lose power under load.  Ended up being a bent push rod.  My generator backfired and that was a sticking intake valve.  Carbon deposits had it sticking.  Might put a compression gauge on to see if you have a pressure loss.  I now use additives in the gas.  I ran some Seafoam through to help clean it.

[dnalley]

News is better tonite.  To start with there was about a fifteen inch fuel line from the fuel pump to the carb that I hadn't replaced, so I replaced that, checked all the hose clamps, (some didn't seem to be tight enough---thought I might be getting a little air into line), and drained the sediment bowl about four times.  Definitely had a little water and trash in bowl.  Still popping but less.  So in looking I checked the linkage for the choke.  Moved the choke lever off the hard stop while looking at the choke linkage---just enough to relieve the tension on the wire rod, and instantly the popping stopped!  Makes no sense to me but you've all heard about the blind hog finding an acorn.  Something had to move or break loose when I barely touched that choke linkage, 'cause  since that happened that thing's been running like a scalded dog.  Once again, thanks for all the ideas.  Great help ;D  Wasn't popping at dark so high hopes for tomorrow!     Dwight

Laffs---at the risk of showing my ignorance---what in the world is "dry gas" ???

[JV]

Glad to hear you found the problem.  Sometimes these things can drive you nuts trying to locate them.

"Dry Gas" is an alcohol based additive if you have or may have water in the tank.