Recommeded Spark Plug 150 Johnson

[Crashtackle]

I want to put a new set of plugs in my motor.

150 Johnson V6 Oceanrunner with carbs.

I have NGK BPR7HS in it now.

Is that the right plug?

Crash.

 

[seahorse5]

Re: Recommeded Spark Plug 150 Johnson

A model number normally would help us with determining the exact plug needed, but lucky for you, any 150 Oceanrunner uses the Champion QL78YC plug gapped at .030".

You have the wrong plugs in there now as they are not a suppressor style that your motor requires. Usually it's the "carport cowboys" and the untrained "mechanics" who put the wrong NGK's in a person's Johnson or Evinrude outboard.

 

[Vic.S]

Re: Recommeded Spark Plug 150 Johnson

As seahorse 5 says the NGK plugs you have are not correct.

The "R" in number indicates that they are resistor plugs, which are unsuitable for OMC ignition systems.

The Champion "Q" series plugs have inductive, low resistance, suppression and are the ones you should be using.

There does not seem to be a direct NGK equivalent for QL78YC. The nearest would be BZ7HS-10. The "Z" in the number indicates that it is inductively suppressed but it is not a direct equivalent, not having a projected nose, and may or may not be suitable.

Below is the extract from the plug listing that covers 150hp models

150, 175 (60? V6) 1991 & newer ...............QL78YC (see note 3).. 0.030"
150 Commercial (60? V6) 1993 - 2001 ........QL78YC (see note 3).. 0.030"
150, 155 (90? crossflow V6) 1978 - 1987 ....UL77V or L16V ......... Surface Gap
150, 175 (90? crossflow V6) 1988 - 1991 ....QL77JC4 (see note 3).. 0.030"

Note 3 reads: On ALL VRO/OMS equipped motors the "QL" supressor plug is recommended.

 

[Tim Frank]

Re: Recommended Spark Plug 150 Johnson

Re: Recommended Spark Plug 150 Johnson

Notwithstanding the opinions above, the plug that NGK recommends for that motor is BPZ8HS-10

But heck, what do they know....

 

[dazk14]

Re: Recommended Spark Plug 150 Johnson

Re: Recommended Spark Plug 150 Johnson

Notwithstanding the opinions above, the plug that NGK recommends for that motor is BPZ8HS-10

But heck, what do they know....

The 8 heat range of an NGK is too cold of a plug for that motor. Been there done that.
Stick with the champions.

The "-10" NGK's come gapped at .040, but the jury's still out on that spec..

 

[Vic.S]

Re: Recommended Spark Plug 150 Johnson

Re: Recommended Spark Plug 150 Johnson

Notwithstanding the opinions above, the plug that NGK recommends for that motor is BPZ8HS-10

But heck, what do they know....

Well well well they get the right type of plug this time.
An Inductively suppressed plug. "Z" to match the Champion "Q" and a projected tip, "P" to match the Champion "Y"

But for the Dazk14's experiences I would not have quibbled with the grade 8 heat rating but there you go NGK spoil things by recommending a plug that is too cool even when they get the rest right.

It confirms what both Seahorses and I both said that the BPR7HS which the OP has fitted at present are incorrect.

I will revise my suggestion though to use BPZ7HS-10 I had not realised earlier that the "P" versions existed.

Regarding the plug gap the usual advice from Joe Reeves and others is that you use 0.030" (0.7-0.8mm) or 0.040" (1.0mm) whichever works best!
I believe the gap recommendation was changed from 0.040" to 0.030" to improve plug life across practically the whole range.


Now if NGK always got at least the suppression type correct they might not have acquired the reputation for being totally unsuitable for Johnsons and Evinrudes. Their loss perhaps. Champion's gain.

The link you gave on another thread gives the wrong plugs for my Evinrude. As it so happens I have set of unsuppressed NGKs, bought before I found out what all the code letters meant. Luckily my local chandler did not sell me resistor plugs! Must get the "Z" series ones for it one day. (Or a new set of Champion QL77JC4) They might reduce the radio interference a bit!

 

[seahorse5]

Re: Recommeded Spark Plug 150 Johnson

I haven't priced them recently, but the NGK "Z" series sparkplugs for the Johnson and Evinrudes usually cost more money than the factory recommended "Q" series Champion plugs.

 

[Dhadley]

Re: Recommeded Spark Plug 150 Johnson

Regardless of what any spark plug manufacturer recommends I'd go by what the engine manufacturer recommends for any one of their specific motors....

 

[Vic.S]

Re: Recommeded Spark Plug 150 Johnson

Regardless of what any spark plug manufacturer recommends I'd go by what the engine manufacturer recommends for any one of their specific motors....

Trouble is in the UK at any rate NGK plugs are readily available, presumably because most engine manufacturers recommend them or at least list them as suitable alternatives.
Champion plugs are not so readily available, presumably because only Johnson and Evinrude, which are themselves not so popular in the UK, specify them exclusively.

OK they are available from the Evinrude/Johnson dealers, but they are few and far between and anyway people like to be able to buy plugs from their marina shop or favourite chandler.

Consequently people do buy NGK plugs, often getting, I suspect, resistor plugs when they should not.

 

[Tim Frank]

Re: Recommeded Spark Plug 150 Johnson

Regardless of what any spark plug manufacturer recommends I'd go by what the engine manufacturer recommends for any one of their specific motors....

In which case, you wouldn't suggest using NGK for this application, which is fine.

My point is simply that if you insist on using NGK plugs in the absence of a buy-in from your engine's manufacturer, your second-best source of a plug spec would be the manufacturer of the plug that you have chosen...followed by anecdotal evidence from owners of the same motor....and then any other source...

 

[Vic.S]

Re: Recommeded Spark Plug 150 Johnson

In which case, you wouldn't suggest using NGK for this application, which is fine.

My point is simply that if you insist on using NGK plugs in the absence of a buy-in from your engine's manufacturer, your second-best source of a plug spec would be the manufacturer of the plug that you have chosen...followed by anecdotal evidence from owners of the same motor....and then any other source...

That ought to be the case. Unfortunatey despite the fact that we know that OMC specify inductively suppressed plugs for all engines with CD ignition the link you gave ends up suggesting resistor plugs for some engines with CD ignition, including my own!

You rejected a couple of links explaining that inductively suppressed plugs are required . You dismissed a link I provded to a technical explantion of why they are required rather than resistively suppressed plugs as merely somebody's "opinion", largely because you did not like the URL.
I am, BTW, still waiting to read your technical explanation of why OMC specify the inductively suppressed plugs! Also at the same time perhaps you would like to explain why only "Q" series plugs are recommended for engines with VRO or OMS. I do, I think, know the reasons but I'd like to see your explanation nevertheless.

I am afraid although what you say ought be correct it is not in some cases. If you prefer to use the wrong type of plug in your engines that is your choice but it is not right to recommend what we know to be the wrong type of plug to others.

I do quote from equivalent lists but I always point out that they may not necessarily be exact matches or the even best choice but I do try to ensure that any suggestions I make are at least the correct type, leaving only the heat rating open to question.

 

[Crashtackle]

Re: Recommeded Spark Plug 150 Johnson

Thanks for your replys.

When I looked up my manual and cross referenced the plug and I thought that what was in there was not right. The motor runs sweet and sounds great but it is a long wasy to swim and I want what is in the motor to be what is recommended.

Thsnks again

Crash