Advice on spark plugs please.

[Jonnymac]

Greetings,

I had my rib serviced some weeks ago and on collecting me vessel from the mariner I was told that the spark plugs I had fitted were the wrong ones and he had put in new spark plugs.

I launched my boat last week, it started, then after 30 seconds the engine cut out and would not start again.

It was found that the power pack had packed in so I had a new one fitted. The engine started but when at full throttle the engine revs dropped and picked up again.

My engine is a 2003 Johnson 50 HP, it would appear the correct spark plug should be QL78YC the spark plug fitted during it's recent service was L-78V.

People have told me that having the wrong spark plugs fitted could cause the power pack to break, is this true ?? Also would this be the same for the engine to be losing power at higher revs ??

Thanks guys.

[jyasaki]

Here's what I come up with:

Champion QL78-YC
Details about your spark plug:Type: MARINE Type: AUTOM. Thread size: 14mm (0.55118 inches) Hex size: 0,81 inches (20.574 mm) Reach: 0,5 inches (12.7 mm) Seat type: GASKET Projected tip: YES

Possible spark plugs:
NGK: BPR8HS
NGK: BPZ8HS-10
Autolite: 4092
Champion: QL78YC
Denso: W24FPR
Denso: W24FPR-U10





Champion L78V:
Details about your spark plug:Type: MARINE Type: HI-PERF. Thread size: 14mm (0.55118 inches) Hex size: 0,81 inches (20.574 mm) Reach: 0,5 inches (12.7 mm) Seat type: GASKET Projected tip: NO (Surface, according to NGK)

Possible spark plugs:
NGK: BUHW
NGK: BUHW-2
AC Delco: V40FFM
AC Delco: V40FFK
Autolite: 2872
Bosch: W4AC
Bosch: WEA
Champion: L78V
Denso: SF-50
Denso: SF-51
Motorcraft: AVKOD
Prestolite: 1,40E+002



For info on plugs, take the NGK replacements and look here .

Construction looks somewhat different; Don't know if that's a problem for you or not.

jky

[Jonnymac]

Thanks very much for your reply.

[buzzin hornet]

Jonnymac

Contact these guys (Turbo diesel on here)

Black Dog Marine boat engines - outboard and inboard diesel and petrol motors installed

Good guys/ good service.

Ive used them for my engine seal kit.

Cheers

Buzzin