Source to identify hotter spark plugs by model?

[Good Trout To You Sir]

In my OMC small motors, I would like to try hotter plugs versus those specified by BRP on its site.
Anyone know of a matrix that might show alternate plugs according to OMC model & year?
Any reasons against trying hotter plugs?

 

[racerone]

Do you understand " hotter plugs "------It certainly is NOT a hotter spark.------And yes you risk engine damage.-----What is your motor doing / not doing ??

 

[Good Trout To You Sir]

I stand corrected.....wish to identify plug with a hotter spark, unless not recommended.
Witnessing some power loss. Just administered Seafoam decarb using engine FAQ technique. Would like to change plugs at same time to see if hotter spark may help. Current plugs are quite old. Probably have 300 hours on them.
What do you suggest on plugs?
What do you suggest on other maintenance?

 

[Scott Danforth]

put in the correct plugs

check your compression

 

[Good Trout To You Sir]

By "correct" you mean the BRP-specified plug?

 

[F_R]

What motor are we talking about? There are a few cases where the original factory recommended plugs were not the best choice and newer recommendations were made.

 

[jimmbo]

Stay away from the Champion Plug finder. It wants to put J8*s into every old OMC

 

[Good Trout To You Sir]

Motors:
1998 4HP Model: E4BRECRJ
1969 4HP Model: 4906B-E01558
1987 2.5 HP Model: E3RCUA
Are there better plugs than those specified in the BRP plug finder?

 

[racerone]

Only if you OPEN the gap on the sparkplug will get you a hotter spark as more voltage is required to jump the gap.----- "Hotter " sparkplugs DO NOT produce a hotter spark !!!----It has to with the ability of the sparkplug to get rid of heat.-----Proper adjustment of points ( if so equipped ) will get you the highest / quickest voltage rise and a hot spark !!!----Do not look at the plug type to get " hot spark "

 

[jimmbo]

Do you run the motor(s) at idle non stop for hours? If so, then maybe, just maybe, you may need a hotter plug

 

[Good Trout To You Sir]

Running speeds are variable. Unusual to idle for hours.
So for a hotter spark, increase the gap on the plug.....from the OMC standard recommendation of 0.03 to ????

 

[F_R]

I don't have the info for the '98
1969 use J6C. If you truly want a hotter-running plug for extended trolling, use J8C.
1987 use QL86C

Changing plug gap does not make the plug hotter. But increasing the gap does force the spark voltage higher not hotter.

 

[jimmbo]

Why did you think you need a Hotter Plug? Please explain

 

[thatone123]

I use NGK plugs for all outboards period, never any plug related issues.

 

[jimmbo]

I find that Mercs that came with NGKs continue to do fine with NGks as replacements, OMCs that came with Champions often have issues with the NGKs. I don't know if it is a problem that the supposed Heat range is not a direct crossover. My personal favorite Plug, for our OMC engines were ACdelcos