Snap , crackle,pop after 3 minutes

[Oldcpecdr 255]

 

While you are hooking up the temporary fuel supply......

 

Make sure  the intake bolts are snug at the carb and at the engine block..and that the gaskets are there.... an intake leak at PART throttle can really lean it out and give you a snap crackle pop..

 

Mike B

[bc.gold 3,406]

How well does the engine run low rpm the first 3 minutes on first start up.

 

If it runs decent for those first three minutes and good at wide open throttle, I'm going to take a stab and say the valve tappets needs adjusting.

 

Fold a piece of cardboard to make a hinge then place this over the exhaust, if the valves are leaking the cardboard will make a flap flap sound as its drawn in against the exhaust. Valves in good working order will push the cardboard away without it being sucked back against the pipe.

 

If  you get the flapping sound then adjust the valve tappets, when the engine is operating at full throttle it's getting maximum air flow, valves borderline out of adjustment would be satisfied with the good airflow..

 

 

[johnnymag3 2,569]

9 hours ago, tunahead72 said:

 

I'm being thrown off by this photo...  The vertical muffler tells me the engine is a K series, but it does look like a Magnum peeking out behind it.  Don't know if it matters, but has the exhaust been modified at all?

 

that muffler was on there prior to restoration, it now has a horizontal muffler that belongs with the tractor. OEM Nelson on it now. 

[JCM 10,202]

I have been following this and had a similar issue with the C-165 for many years but having other WH's that were a little newer and tighter I never really spent the time or effort to correct the problem. I decided to bring the tractor up to northern Maine and use  it for light duty pulling a cart around between the 2 camps. Before bringing it north I replaced the following parts so other than oil changes hopefully would not have to do much to it. By the way this tractor had all of it's original parts but was as they say, rode hard and put away wet.  New fuel lines, OEM fuel pump, fuel filter, spark plug, Napa battery, seat switch, air filter and fresh gear oil. After all of this it was slightly better but something was still amiss. Eventually brought the 165 back home and it again sat for a while. From reading many posts on here I thought it was a good candidate for a throttle shaft bushing and thanks to @ebinmaine it did help but still something else lurking . I noticed a trace of oil where the plug wire goes into the coil,having an old coil from the C 120 that was original but replaced it just because I swapped it out and that seemed to have calmed the backfire issue along with the throttle shaft bushing.I ended up putting a 42'' RD deck on it and tried mowing with it but it was still not right. My last resort within my mechanical abilities was to try a new plug wire and the intermittent backfiring and  the tractor slowing down when going up a slight incline is now a distant memory. I do however think the 165 may have a carbon issue like Eric has mentioned because of possibly the amount of hours this machine may have on it and a lack of sufficient maintenance before I acquired it. I also am talking my own experience as this is a K Series and not a Magnum and may not relate to your issue.      Thanks for listening.       PS  forgot to mention carb rebuild.

[johnnymag3 2,569]

Going down to the Corral to connect a gravity feed to the 310....if problem exists, then its electrical. I tried 3 Carbs, with same results....Tank is clean, lines are new, filter changed last night again, ran the same with no filter....what a fussy Horse. !!   

   Will follow up after fuel experiment with external gas tank going into carb. Throttle bushings are tight, also the carb im using is from a perfect running 312.

 

Thanks everyone !!

[bc.gold 3,406]

22 minutes ago, johnnymag3 said:

Going down to the Corral to connect a gravity feed to the 310....if problem exists, then its electrical. I tried 3 Carbs, with same results....Tank is clean, lines are new, filter changed last night again, ran the same with no filter....what a fussy Horse. !!   

   Will follow up after fuel experiment with external gas tank going into carb. Throttle bushings are tight, also the carb im using is from a perfect running 312.

 

Thanks everyone !!

 

Cardboard is cheap and the fold is free.

Edited June 22, 2020 by bcgold

[Tractorhead 9,209]

Another question, that come in mind, 

whar rpm your Engine idles?

[johnnymag3 2,569]

ok,,,,,,,so I did the external tank, with shut off, and new filter....................

 

Same thing happens... It acted up in less than 2 min.

Time to rethink this crazy Horse...

[johnnymag3 2,569]

Had the head off last year, things are spotless.....check valves AGAIN, well within normal settings.

 

What next ????

 

Thank you, John

[Tractorhead 9,209]

Get you mobile phone, record the running as a video ( 3 min are no problem normally)

put it in youtube and give us a link here on Red Square.

 

it‘s allway‘s hard to „read“ a noise description instead of hear it.

some noises in the background may give an indicator what may happens.

 

[squonk 43,821]

My best guess at this point with everything covered fuel wise you have an issue with the ignition trigger. Napa sells a cheap inline spark tester. If you had one of those you could see if the spark gets erratic with the problem showing up. Napa  # 7760017

 

https://www.napaonline.com/en/p/BK_7760017?cid=paidsearch_shopping_dcoe_google&gclid=EAIaIQobChMI2IGTveKV6gIVCr3ACh1JHganEAQYASABEgKRYvD_BwE

[bc.gold 3,406]

Cardboard flap will also tell ya if you have a sticky valve guide.

[johnnymag3 2,569]

32 minutes ago, Tractorhead said:

Get you mobile phone, record the running as a video ( 3 min are no problem normally)

put it in youtube and give us a link here on Red Square.

 

it‘s allway‘s hard to „read“ a noise description instead of hear it.

some noises in the background may give an indicator what may happens.

 

I have a flip phone, but asking a neighbor to record it for me

[johnnymag3 2,569]

maybe a video here....ugh

javascript-packed.js.download

Edited June 22, 2020 by johnnymag3
addition

[gwest_ca-(File Mod) 11,483]

Try a shot of Marvel Mystery oil in the fuel but run it long enough for the valve stems to benefit from the lubrication it provides. 2-Stroke oil in the fuel will work also.

 

Garry

[johnnymag3 2,569]

Took the reinstalled items from the tractor out for a spin....It ran perfect for 30 min. Then I pulled in front of the garage to put it away..idled it down and SNAP CRACKLE POP POWWWW   SAME AS BEFORE. This machine will run all day long on half throttle, or full throttle....but as soon as its idled down, and I used 3 carbs...... It carries on like a wild popcorn maker, then stalls. When its running normal, it purrs like a kitten, Tappet clearance perfect, dont know where to go.....gravity fuel tank....same as with normal tank....HELP

[pfrederi 18,670]

Did it run OK last year after you had the head off???  Did it ever run right??

[Tractorhead 9,209]

@pfrederi

Have this Engines a auto decompression function?

 

I’m not Familar with that Enginetype, but it sounded to me on description,

it idles too low and a deco will interrupt the run.

[lynnmor 7,817]

If you have a timing light you may be able to see if the spark is jumping around at some speeds.  My thought is that the magnets in the flywheel or the stator is knackered.

[johnnymag3 2,569]

3 hours ago, pfrederi said:

Did it run OK last year after you had the head off???  Did it ever run right??

It Did....thats what makes this so confusing. The machine was the same every year I serviced it. Last year, or maybe the year before it was partially restored, not mechanically, but aesthetically. he uses Marvel and sea foam in winter, and has me go through it each Spring. This year its acting so weird with this spit cough backfire thing, I just ran this thing all over the place for 30 min. And no issue. idle down and immediately it acted up...SNAP POP POW.    Stall,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

[johnnymag3 2,569]

2 hours ago, Tractorhead said:

@pfrederi

Have this Engines a auto decompression function?

 

I’m not Familar with that Enginetype, but it sounded to me on description,

it idles too low and a deco will interrupt the run.

anything below 1/2 throttle and it acts up...1500 rpm or less

[johnnymag3 2,569]

The Saga continues...............

[johnnymag3 2,569]

Im done with this engine, so finished with hours spent on it with no results. Im suggesting that he buys the 16 HP on my local paper for 200.00

Seems like there are no answers for this problem. Its a K series, off a C 160.....a real engine !

[johnnymag3 2,569]

Ive got 16  or more hours in this thing, no recovering that

[johnnymag3 2,569]

Coil.......keyway......plug wire / coil.    anything else ?

 

What am I missing?????

I do appreciate all of the input, but most of the ideas have already been spent......This is not a typical mow the grass mower, and lives indoors, on a darn carpet for pete's sake !!!

 

There has to be another guy or gal with this same issue at some point in time....As they say in Maine....its WICKED annoying !

 

I love Maine, and will be going there to retire.....in 11 months