Spark Plug Problem

[Tailortaker]

G'Day All,
I just bought some new Champion copper marine plugs for my 2000 model Johnson 25 hp 2 stroke. They are excactly the same as the old plugs but I'm sure there is slighlty less power than before. Would there be any reason for just a slight power loss???
Thanks TT

[Angla]

I could only imagine that the gap distance is maybe less than on the old plugs, therefore giving you a smaller spark and reducing the fuel burn.

Chris

[Roughasguts]

Mate put the old ones back in and keep the new ones for a spare.
Around 3 years ago I bought a batch of ordinary plugs, so I guess dodgy ones will happen.

[Mac_Attack]

Hey TT
I have a 30 HP 2-stroke and i thought she had some go untill i put some oridium spark plugs in her. They may be expensive but they last for ever and they give you alot more power.
Cheers Nick 8-)

[Kleyny]

IMO i wouldnt put champion in my lawn mower.
when i was swinging spanners i had allot more duds with champion than i did with NGK.
i also agree with mac oridium plugs are much better than normal. i havent put them in my boat yet but they made a differnce in my dirt bike.

neil

[Tailortaker]

Thanks guys, so where can I get oridium plugs from ?
Cheers TT

[Mac_Attack]

Thanks guys, so where can I get oridium plugs from ?
Cheers TT

Hey TT
Just walk into any Auto 1, Super Cheap, Repco or a store like that.
And ask for NGK Ridum BR7HIX plugs. There what i use in mine which is 30HP Mercury.
Cheers Nick 8-)

[Spaniard_King]

TT, You cant just chauck in any old iridium plug. I would be cross referencing the model plug you have now for the iridium version.

I think you will find that the merc runs a diff model plug.. ie electrode protrusion heat range etc..

Is mac attack going to subsidise the repairbill if your engine goes "BANG" due to the wrong plug???? :P

[4x4frog]

Try the NGK websitem they have cross reference guides there........I agree with the use of Champions too, I have always used and recommended Bosch plugs for anyone who asks and I have only ever used them exclusivly in my cars, except for one try of Champion Golds. Never again.

[Mac_Attack]

TT, You cant just chauck in any old iridium plug. I would be cross referencing the model plug you have now for the iridium version.

I think you will find that the merc runs a diff model plug.. ie electrode protrusion heat range etc..

Is mac attack going to subsidise the repairbill if your engine goes "BANG" due to the wrong plug???? :P

I take no responsibility for my advice you do with it as u may

[Tailortaker]

I've crossed referenced my chamoion plugs to NGK equivelent but cant match it to iridium ? If I go to a standard NGK would I miss much power between it and iridium and do I buy standard ngk or is there a marine one ?
Cheers TT

[tunaticer]

I converted over to surface gap plugs near on 12 yrs ago now in my 25 evinrude and they still never miss a beat. Mate has an identical motor and runds std plugs and has to change them about every yr or so.
I honestly cant feel or sense any difference in power but my plugs just dont wear out or build up with carbon.

Jack.

[tigermullet]

I've crossed referenced my chamoion plugs to NGK equivelent but cant match it to iridium ? If I go to a standard NGK would I miss much power between it and iridium and do I buy standard ngk or is there a marine one ?
Cheers TT

On the Internet the NGK site has a conversion from standard to iridium plugs.

The equivalent to NGK BR7HS10 or B7HS10 is BR7HIX.

The equivalent in Denso plugs is W22FS-U10.

Years ago I ran the Denso plugs but have found them to be difficult to get hold of now. Denso claim to have a smaller (and more efficient) electrode. The old 30hp Mariner did seem to run much better and there was a noticeable increase in power with iridium plugs.

As far as I can determine there is no difference in plugs for marine use but please do your own research.

[FNQCairns]

I have just had a NGK plug die on me after only 30h use so just changed them all out.

Have always considered the special plugs snake oil in standard equipment but my belief is 10 years old, is there really a perfrmance increase in these irdiums? like if it really does give more HP then it must also give better fuel economy, noticeable on a fuel meter I would guess anyone notice this advantage?

Would be a worthy buy if they do!

cheers fnq

[4x4frog]

On the Internet the NGK site has a conversion from standard to iridium plugs.

The equivalent to NGK BR7HS10 or B7HS10 is BR7HIX.

The equivalent in Denso plugs is W22FS-U10.

Years ago I ran the Denso plugs but have found them to be difficult to get hold of now. Denso claim to have a smaller (and more efficient) electrode. The old 30hp Mariner did seem to run much better and there was a noticeable increase in power with iridium plugs.

As far as I can determine there is no difference in plugs for marine use but please do your own research.
I have bought Denso plugs from FOrd parts places in the past and they have a good range in stock. They are good for plugs for older engines because they still keepa decent range for the old Ford motors.
The comment about surface gap plugs is a good one too as I have amate who used them exclusively in a Merc 50hp 20 years ago now and swore by them then.
Another option would be to go witha Bosch multi electrode plug, either a twin or triple electrode. These plugs give better ignition because of the gerater choice of routes for the spark to travel.