1989 E88MSLCER Spark Plug and Gap Question

[drobertsobx]

Hi
The specs for the motor are Champion QL77JC4 (Cold) or QL82C(Hot).
It had NGK's in it when I bought it (BZ7HS)

Champion QL82C=BZ7HS-10 (Hot) NGK Cross Reference
Champion QL77JC4 = BR9HS-10(Cold) NGK Cross Reference

I want to put a fresh set in before my first trip.
I'm using in the wintertime, at mostly idle to low speed(under 2k) in the dark, so running a hot plug shouldn't be an issue, and should help with keeping the electrode carbon free.

On the NGK the -10 is for 1mm Gap =0.03937008

The spec is 0.028-0.033
Should I bother re-gapping the Plugs?

I read a mix between .03 and .04 but none in these conditions or this motor or HP

Thanks
Don

 

[racerone]

Plug gap is not that important in my opinion.----0.030" or 0.040" will make little difference.-----Making sure that thermostats are not stuck open should be high on your list of things to check.----New water pump impeller and test the overheat horn to

 

[drobertsobx]

Plug gap is not that important in my opinion.----0.030" or 0.040" will make little difference.-----Making sure that thermostats are not stuck open should be high on your list of things to check.----New water pump impeller and test the overheat horn to

Thank you for the reply...

Installed New Pump on day 1.
Had an overheat issue
I pulled heads and descaled. Re-installed with all new gaskets.
Still had an overheat issue.
Installed new thermostat kit.
Still had an overheat issue (starboard side was air locking)
Pulled housing again and reemed the air hole in the plate and did the poppet valve notches. Problem solved.

Horn works and I wired a warning light and on demand light and horn momentary switch into the grounding circuit for the horn, works perfect.

I also installed a Faria Outboard Head Temperature guage with external sender on the starboard head (was always the warmest with laser) runs right at 140-150+- all day last time out.

 

[Vic.S]

Hi
The specs for the motor are Champion QL77JC4 (Cold) or QL82C(Hot).
It had NGK's in it when I bought it (BZ7HS)

Champion QL82C=BZ7HS-10 (Hot) NGK Cross Reference
Champion QL77JC4 = BR9HS-10(Cold) NGK Cross Reference

I want to put a fresh set in before my first trip.
I'm using in the wintertime, at mostly idle to low speed(under 2k) in the dark, so running a hot plug shouldn't be an issue, and should help with keeping the electrode carbon free.

On the NGK the -10 is for 1mm Gap =0.03937008

The spec is 0.028-0.033
Should I bother re-gapping the Plugs?

I read a mix between .03 and .04 but none in these conditions or this motor or HP

Thanks
Don

The recommended plugs are Champion QL77JC4 or QL82C , gapped at 0.030"
The "Q" indicates inductive suppression Although you could use unsuppressed plugs you should not use resistor supressed plugs such as NGK BR9HS-10 ( the R in the number indicates resistive suppression)
A "Z" in the NGK number indicates inductive suppression

NGK BZ7HS-10 is a suitable plug and is often quoted as the equivalent of Champion QL77JC4 while no exact equivalent of QL82C may be given.

As Racerone suggests you are unlikely to notice any difference between 0.040" and 0.030". A few years earlier the standard gap more or less across the board was 0.040" but at some point in the late 1980s this was changed to 0.030". I believe the reason was to reduce electrode erosion and extend plug life.

 

[drobertsobx]

The recommended plugs are Champion QL77JC4 or QL82C , gapped at 0.030"
The "Q" indicates inductive suppression Although you could use unsuppressed plugs you should not use resistor supressed plugs such as NGK BR9HS-10 ( the R in the number indicates resistive suppression)
A "Z" in the NGK number indicates inductive suppression

NGK BZ7HS-10 is a suitable plug and is often quoted as the equivalent of Champion QL77JC4 while no exact equivalent of QL82C may be given.

As Racerone suggests you are unlikely to notice any difference between 0.040" and 0.030". A few years earlier the standard gap more or less across the board was 0.040" but at some point in the late 1980s this was changed to 0.030". I believe the reason was to reduce electrode erosion and extend plug life.

Thank you for the info, as the bz's in it seem to be functioning well I think I will keep them as my default. I'm not to concerned with plug life, so will keep them at 1mm. It is a small price to pay for having a motor that starts on half a crank, and runs all day... I will just keep a note in my log to keep an eye on the electrodes.