Briggs and Stratton Spark plug question ??

[fins]

I have an older riding mower with a B&S Model 287707 14.5 OHV engine.
Sticker on the mower says use a 5062 spark plug, there is a B&S 491055 in it now.
Also shows Champion RJ19HX as an alternate plug, others say use RC12yc.

What's best recommendation??

​

 

[nate379]

I have an older riding mower with a B&S Model 287707 14.5 OHV engine.
Sticker on the mower says use a 5062 spark plug, there is a B&S 491055 in it now.
Also shows Champion RJ19HX as an alternate plug, others say use RC12yc.

What's best recommendation??

​

Why does it gave multiple stickers giving different part numbers? 5062 is a RJ19HX

 

[SC Maintenance]

I would personally use the Champion RJ19HX since that is what it calls for. Or a NGK cross. The RC12 would be a much hotter plug.

I tried a B&S plug from walmart in my mower and it ran like crap. Not sure if I got a dud, but I won't use them again.

 

[mccandish]

The B&S replacement for a 5062 is part number 796560.

Table here

 

[Nukeman7]

The correct spark plug for that specific B&S engine is the Champion RC12YC which cross-references to a B&S 491055 plug which is what is in there now.

Maybe the riding mower has a replacement engine than what originally came with it; hence the disconnect with the sticker. FYI, the B&S 491055 plug is made by Champion and is just a relabeled RC12YC.

 

[Soft Cars]

Briggs & Stratton 491055.

For Type numbers 1237 & 1287,
Use Briggs & Stratton 691043.

 

[slacktide_bitog]

If RC12YC is the correct plug, use NGK BKR5E. If you want iridium, the Denso IK16 will fit, and possibly even the IK16TT

There's also the Autolite XS3924

 

[mk378]

This makes no sense as the 5062 and RJ19HX are short threads style plugs, typically used in flathead engines. The other plugs discussed are long threads. Most OHV engines use a long plug. You'd know right away trying to put one in an engine built for a short plug.

Maybe the riding mower has a replacement engine than what originally came with it;

Seems like the case. Ignore the sticker on the mower, it is for a different engine.

 

[jeepman3071]

This makes no sense as the 5062 and RJ19HX are short threads style plugs, typically used in flathead engines. The other plugs discussed are long threads. Most OHV engines use a long plug. You'd know right away trying to put one in an engine built for a short plug.


Seems like the case. Ignore the sticker on the mower, it is for a different engine.

This was my initial thought as well when I read the OP.

There are two different style plugs listed. If it takes an RJ19LM short plug, definitely don't stick an RC12YC long plug in there. Given that the OP stated it is a 14.5 OHV engine my experience would tell me it needs the RC12YC plug and that is likely the factory spec. Throw one of those in it and motor on.

 

[Pablo]

I have an older riding mower with a B&S Model 287707 14.5 OHV engine.
Sticker on the mower says use a 5062 spark plug, there is a B&S 491055 in it now.
Also shows Champion RJ19HX as an alternate plug, others say use RC12yc.

What's best recommendation??

​

A bit confusing. I looked at NGK (which I HIGHLY recommend, but also saw some conflicting numbers)

I would contact NGK and ask.

Contact Us - NGK Spark Plugs

Contact NGK to learn more about our products and services.

ngksparkplugs.com

 

[jeepman3071]

A bit confusing. I looked at NGK (which I HIGHLY recommend, but also saw some conflicting numbers)

I would contact NGK and ask.

Contact Us - NGK Spark Plugs

Contact NGK to learn more about our products and services.

ngksparkplugs.com

I love NGK plugs and use them exclusively in the Japanese engines and Predators, but it can be a bit confusing to cross over which ones are actually recommended for Briggs, Kohler, and Tecumseh engines. I find Briggs/Tecumseh/Kohler are not as picky, and will run on a 40 year old plug just fine, so I usually just throw in a new Champion and never have an issue.

 

[Pablo]

I love NGK plugs and use them exclusively in the Japanese engines and Predators, but it can be a bit confusing to cross over which ones are actually recommended for Briggs, Kohler, and Tecumseh engines. I find Briggs/Tecumseh/Kohler are not as picky, and will run on a 40 year old plug just fine, so I usually just throw in a new Champion and never have an issue.

It takes a little effort for sure, but seems worth it for me.

I swore in 1975 I would never ever use another Champion plug. I'm sticking with that because whenever someone is over or I'm at their place or at a race, or dock, or garage and there is a no spark situation, taking Champion plug out = 100% has solved the problem.

 

[jeepman3071]

It takes a little effort for sure, but seems worth it for me.

I swore in 1975 I would never ever use another Champion plug. I'm sticking with that because whenever someone is over or I'm at their place or at a race, or dock, or garage and there is a no spark situation, taking Champion plug out = 100% has solved the problem.

I've personally never had a bad one, but I know people who have so I get it. My latest struggle seems to be buying actual genuine NGK plugs.

 

[RyanY]

I've personally never had a bad one, but I know people who have so I get it. My latest struggle seems to be buying actual genuine NGK plugs.

I found that Advance Auto price for NGK plugs is close to others, after the 15% online order bonus, and i am confident it is legit NGK. Of course, I only replace the lawn mower plug every two years, so an extra dollar for peace of mind is money well spent.

 

[SJ323]

You can use the "reverse engineer a part" tool on sparkplugs.com to find the best alternative to an rc12yc. I entered all the size specs in this link: https://www.sparkplugs.com/search/r...true&specs=165272,165275,165281,165308,165318

Make sure the new spark plug heat range matches the stock (rc12yc) plug. Champion 12 = Bosch 8, NGK 5 and Denso 16. Also make sure the gap sizs is correct for your mower's engine. I think yours is .030". You can confirm that by entering the full model number on the Briggs and Stratton site to get your owner's manual.

If you have to adjust the gap use a wire style gap tool and open or close the plug no more than .008" or you risk putting the precious metal pads on both ground and center electrodes for double platinum, iridium or ruthenium plugs out of alignment. Also, make sure the projection type is the same as the stock (rc12yc) plug or it may hit the piston.

Yes, I realize what I said was probably a mouthful. But I wanted to give anyone else viewing this thread the option of doing it themselves for their specific situation. If you don't want to go that route, post the full engine model number e.g. 287707-1224-E1 and I'll find the best alternative you can go with. I'm assuming you want a long lasting plug?

 

[Lubener]

I would personally use the Champion RJ19HX since that is what it calls for. Or a NGK cross. The RC12 would be a much hotter plug.

I tried a B&S plug from walmart in my mower and it ran like crap. Not sure if I got a dud, but I won't use them again.

Champion RJ19HX is hotter than RC12. With Champion, higher the number, hotter the heat range.