What order for tuneup? and stop backfiring? 416-8

[ibskot 37]

Sounds like a sticking or burnt intake valve to me as the "miss" seems quieter

when you close throttle back down.I would investigate weather or not it is a

backfire out of the carb as thats what it sounds like to me. If so you need to pull the head

and look at your valves. :tools-wrench: Or they may just need adjustment??

Also, if this were the case wouldn't it sound like that all the time? Sometimes it runs perfectly, like when I first saw it...doh!

[roscoemi 245]

Sounds like a miss. Check the fuel supply as already stated, and yes add an inline filter. Did you put some dielectric grease in the plug wire boot before putting it back on? I've had spark leaks from them before, been fighting one on my truck for years even with new parts and grease. I agree with Boo, put it in the dark and run it, a light mist from a spray bottle will help make shorts show themselves.

[KATO 115]

I wasn't referring to the backfire when you shut it down . I was listening to the "miss"

popping noise . It seems worse when you open the throttle and hold it open.

then quieter when you close the throttle. I would check to see if it is "Spitting" out of

the carb when u do open the throttle (back fire was maybe a bad choice of words).and it is possible

for a valve to stick intermittently.... Just another thing to check on

[ibskot 37]

Thanks for all the responses. Hope I didn't buy a lemon. Sitting at work reading these is discouraging. I'll be back home around 2330 at which time I'll fire it up to see if it sparks or a wire that flickers. If not I will try the other things Saturday. I have a fuel filter to put on. Maybe I should just replace the fuel line anyway.

No, I didn't put the grease on the plug. I'll get some of that too.

Thing is, sometimes it sounds good. Wierd.

If if is a valve issue, does that mean the motor is shot? Is this rebuild time?

[leeave96 487]

You probably should do a thorough maintenance.  Clean and put a new kit in the carb, pull the head and decarbon it, new head gasket and check the valve settings.  None of these things are particularly hard to do, but the first time around it might seem a little intimidating - second time around a breeze.  You should be able to go to the Kohler website and download the service manual for that engine - and it might be on this site in the manuals section too?

 

The good news is - the engine fires and runs and it doesn't smoke.  So I think you're close.

 

Good luck,

Bill

[roscoemi 245]

Dude, you didn't buy a lemon. You have a machine that is playing %#@#%***^ around with you! These tractors are simple, and the problem will be simple to fix once you find it.  The problem is finding it. I had the same problem only worse on mine, the po went thru the fuel system, coil etc. He gave up and gave it to me and a $5 condenser fixed it. If yours has a electronic ignition and all connections are tight and leak free, all your grounds are good, then I would look to the plug and wire. You said the problem is intermittent, therefore most likely electrical when it finds another place to go other than where it's supposed to.

[ibskot 37]

Roscoemi, nice use of "dude" to lead a sentence.

Update, got home, fired it up and if ran good and sputtered. No lighting around plug or wire.

[Jrblanke 840]

I also want to encourage you. You definitely didn't buy a lemon. Your engine doesn't smoke or knock, so I don't think we are talking about an expensive issue, just one that will need a little bit of time and using the ol' noggin. I was intimidated by these lawn tractors at first, because I had not worked on them before. I rebuilt the carb watching a youtube video, and when I got it back together I thought to myself....that's it? Removing a cylinder head and head gasket on one of these is MUCH easier than doing one on a car, so when you hear the words "head gasket" and "cylinder head" you don't have to get the heebee jeebee's. Plus there are folks here that can walk you through pretty much anything! 

 

I have really enjoyed seeing your WH journey so far!

 

James 

[1989520HC 13]

That sounds like a Hit and Miss engine....well take off the air cleaner and see if flames shoot out the carb when its running. I would do a compression test first. Im thinking you have a burnt valve,blown head gasket. All are pretty easy to fix.

[WH nut 553]

That's a Magnum with magneto ignition. I would pull the fan shroud off and make sure the flywheel isn't rusted and the mag is clean. Check the wires while you are in there. Another thing you can do is unplug the wires going to the motor after its running to see if it clears up. If it does you have a wiring problem other than the motor. If that motor will spin and have fuel and fire it will run all buy itself. The mag gets grounded to kill it.