418a kohler m18 spark plug replacement

[ernie laware 8]

want to replace the champion plugs--rv17yc on my m18 kohler--thought maybe ngk ur4 would be a better application as the champion's do not seem to be as trustworthy as they used to be--also only use my 419a for snow removal with a wo238 berco mac 2 stage blower.

Any help?

Ernie

[pfrederi 18,335]

or Autolite 26.  I don't buy Champions any more either.

[Jerry77 1,218]

2 hours ago, pfrederi said:

or Autolite 26.  I don't buy Champions any more either.

[hondagod64 81]

I was an Auto tech for 30 plus years and nothing but problems with champion spark plugs in the earlier years,,,they seemed to work okay in dodge motors but still had failures.

As far as I know before I retired [semi retired ] that NGK which I use in all my motors had purchased champion company and overhauled the complete line.NGK was going after Autolite to purchase them also.NGK is the only company that I know through all the years being in the business that the plug right from the box that the gap doesn't need double checking unless the box was damaged which I wound not use anyways...

 

 

[gwest_ca-(File Mod) 11,251]

When changing to a different manufacturer of plugs the conversion charts should only be used to match the physical characteristics of the plug - threads and thread length

 

Use the application chart for the make of plug you want to use to see what that company recommends. They know what heat range is best for the application.

 

Have seen the conversion charts differ by 2 or 3 heat ranges.

 

Garry

 

 

[Sarge 3,464]

That is very important - many interchanges at parts stores only match physical sizes of the plugs - you're better off using their guide books directly from NGK to get the right plug for that specific engine . I switched to NGK and Denso plugs years ago and they have been far more consistent than Champion or anyone else for that matter and seem to be a lot better overall quality . Thread fit especially which on certain head designs is really critical . Champion , AC Delco , Autolite and others are worthless in comparison to NGK , Denso is even better in certain engines when you get into really fine tuning on a dyno .

 

Sarge

[Skipper 1,789]

We all know that a good spark is one of the key stones for a good running engine and power output. So, has anyone given it a go in a WH with the crazy expensive Super duper iridium what not four prong extra spark hyper drive, spark plugs?

 

If it would help easier startup etc, it might just be worth it? 

[Jerry77 1,218]

5 hours ago, Sarge said:

Autolite and others are worthless in comparison to NGK

??

Have never had a problem with an Autolite spark plug....Made in America since 1911.....think I will stick with the American brand..

[Sarge 3,464]

I have had luck with one engine running those quad tipped plugs - but it's a modern Briggs vertical 22hp that are known to have notoriously weak ignitions and a common miss throughout the rpm band - the E3's seemed to really help and it also fires up easier now . Otherwise , those types of plugs are not designed to fire rich mixtures that are required in these old L head machines . NGK's have lasted far longer than anything , but eventually the carbon buildup will get to the best of them . We had used Autolite for years but then started running into bad batches and I haven't tried them lately...

Sarge

[ernie laware 8]

12/26/17--I did put in the NGK  plugs. It got colder and 418A would not start. Pulled plugs and turned over, wire brushed plugs (new ones) but stillo not start--quick trip to auto store for starting fluid- still no fire, not even a pop. Pulled both plugs, turned over,  then checked for spark. Had just a faint spark with the NGK's--put autolite on wire and had a better spark--even with the old plug. Now running on the old Autolite's.

 

[953 nut 57,994]

2 hours ago, ernie laware said:

Now running on the old Autolite's.

 

On 12/12/2017 at 2:02 PM, Jerry77 said:

Autolite spark plug....Made in America since 1911.....think I will stick with the American brand..

    Guess that answers your question.         

[hondagod64 81]

I've never had a problem with NGK plugs starting in cold or hot weather, it's 5 degrees here right now and I can go out and start my plow tractor with no problem...to me you have other issuses besides plugs...why would you clean new plugs anyways and are you sure you purchased the right plug with the same heat range?

[wallfish 17,507]

Is your tractor hard to start and the reason for changing the plugs in the first place?

When the fuel pump gets weak and the little check valves inside of it leak, it creates a hard start issue. Many have solved this issue with a low pressure electric fuel pump. It made all the difference on my M18 which now fires right up since installing one. They're cheap ($10) and fairly easy to install.

[Sarge 3,464]

NGK's will find a weak coil in a hurry - they do seem a bit tougher to light , but when they do they have a very reliable and solid spark . My old Land Cruiser ran fine on it's old set of Denso plugs but wouldn't hardly run on a new set of NGK's - tested the coil and found it was really weak - new one now and it's lights off with no problem .

It's sometimes not easy to get the exactly correct heat range on NGK plugs - always use their reference book to get the right number for your engine , do not use a cross reference as most of them are wrong . NGK's engineers know more about their plugs than anyone else and their recommendations per the engine application itself are spot-on . Never had a problem with them when I've used their reference books...even in older engines .

 

Sarge

 

 

[hondagod64 81]

WELL SAID SARGE AND THAT IS VERY TRUE , A WEAK COIL AND ALSO OLD SPARK PLUG WIRES WITH HIGH RESISTANCE....