head scratching???

[lobo 22]

Did a rebuild on a 16hsp Kohler, everything went well except now it will sit and idle for about 10mins. or so and then it starts to sputter and almost die then run smooth again for about the same  and starts all over again. Tried draining the gas tank, put fresh gas in it, made sure the fuel was going through, changed the coil and it hasn't made a difference. Was hoping that someone has an idea of what's going on?

[squonk 43,794]

Dirty Carb

[pfrederi 18,664]

Is this a new Chinese carb??  I have had problems with them.  It may run fine at full throttle but has idle issues.  Could all so be dirt in the idle circuit.  Doubt it was the coil but hook up a spark plug tester and see if the flashing changes a lot during the rough phase.

[Handy Don 14,061]

Wondering if the float valve is getting hung up

[Bill D 2,247]

K series or M series.  Possible points and condenser issue.

[gwest_ca-(File Mod) 11,473]

The mixture screw settings are just to make the engine run. They must be fine tuned for best performance after warmup.

 

Garry

[lobo 22]

Okay I'm back, did a rebuild and cleaned the carb, replaced the points and condenser, tried another coil, now don't have spark to the plug.  I've got power to both sides of the coil, no spark to the plug.  It was running the same way as before just before I replaced the points and condenser and now I'm at my wits end. Any advice now would be helpful.

[pfrederi 18,664]

32 minutes ago, lobo said:

Okay I'm back, did a rebuild and cleaned the carb, replaced the points and condenser, tried another coil, now don't have spark to the plug.  I've got power to both sides of the coil, no spark to the plug.  It was running the same way as before just before I replaced the points and condenser and now I'm at my wits end. Any advice now would be helpful.

If you have 12v to the coil and no spark  go back to you points.  Do they open an close as you crank?  Better yet hook up a test light. from the negative coil terminal to ground then crank does it flash on and off???

[lobo 22]

my points open and close as they should, but will try the test light tomorrow

[lobo 22]

tried the test light and I've got spark at the time it's doing the coughing and choking, had one of those brain farts is why I didn't have spark to the plug. I just have no idea what is going on with this but this time it died. It's not one of those China carbs. 

[lobo 22]

I guess nobody has anymore ideas either. I've got alot of wheelhorse equipment that I am considering getting rid of as I'm getting fed up with trying to keep these running. 

[pfrederi 18,664]

How are you testing for spark Just laying it on the head while you crank or a spark plug tester?  You have replaced a lot of stuff.  Try a plug wire from one of you other pieces of equipment that works.  also i would try a new plug Autolite 216

[lobo 22]

I've put a new plug in it already, got a spark tester, tried the spark plug wire off my C-161,  I know it is good. Like I said it runs fine till it warms up some, sure got me scratching my head.

[gwest_ca-(File Mod) 11,473]

May be worth checking the valve adjustment. Too tight will do that.

 

Garry

[seuadr 489]

when it dies, is the carb bowl full?

[lobo 22]

I haven't checked to see if the bowl is full but I have checked that it is pumping gas, plan on checking the valve clearance today.

[ranger 1,798]

What’s the temperature where you are? I had a service van once that had a Weber economy carburettor fitted. It would run all day at high speed, but if you then backed off the throttle it would splutter, and die. We couldn’t find any reason why. It would usually fire up immediately? One day it played up, I stopped, pulled the hood, and jumped out, just in time to see a coating of ‘Ice’ flash off the outside of the carb. The economy carb had a smaller bore than original, the increased air speed through was cooling the carb to the point, icing was occurring when the butterfly closed on the overrun. You mentioned rebuilding the engine? Did you renew the valves? The reason I ask is I remember something about the early “Magnum” engines suffering from exhaust valves binding in the guides when hot, and dealers having to ream the guides to a looser fit. My 312-8 has, I believe, this problem, runs fine in the cooler weather, will pop and bang when worked hard for a while then cut out. Will spin over on the starter very fast, as though no compression, leave it for a minute or two, and it will fire up and run again for a while, then repeat the fun and games. If I run at 3/4 throttle it runs for longer. I’ve changed just about everything on the tractor, no change.

[lobo 22]

Okay, I re-adjusted the valves yesterday, thought  it was working then it started to do the same thing just took longer. When it starts to cough and sputter you can reach up and give it gas, it then coughs up some black smoke and runs fine for awhile, then back to the same. I'm starting to think it's the carb, maybe the rebuild kits I got off flea bay thought I was getting a good deal with a lot of 5, could be China crap. Guess i will try getting a kit from the shop and see if that's it.