spark plugs

[andyhunt]

well lads
heres one for you
how can i check the correct spark plug type for my outboard?
it's a 1991 johnson 25hp commercial two stroke

[blueskip]

I bet ChrisP knows! or knows a site where you can find out, suprised he hasn't already posted! still in bed probably if he has any sense! I'm only on here because "er indoors" wont let me put the fishing on!
blueskip

[Nos4r2]

Ring a dealer and ask them.... I find if you make noises about needing somewhere to have your engine serviced most will give out info for small jobs like that :D

Failing that go to the iboats.com forums and ask the question (give your serial number too) and you'll find out.

[sammyjo]

i mate try giving dulas boats a ring on 01248 410266 hope this helps www.dulasboats.co.uk
andy your right by them in angelsey


did a search on your make try liverpool power boats on 0151 944 1163 they r main agent for johnson in northwest www.liverpoolpowerboats.com/ johnson

[MerseyAngler]

http://www.ngk.com/

[ChrisP]

Champion L82C I think

[MerseyAngler]

If you prefer Champion .... http://www.championsparkplugs.com/

[sammyjo]

well lads
heres one for you
how can i check the correct spark plug type for my outboard?
it's a 1991 johnson 25hp commercial two stroke



hi andy hope your ok now all this should help:clap3:

[andyhunt]

gives me somewhere to start. i just want to make sure i use the right ones.
thanks lads

[scottonjayne]

on the same not i am a machanic by trade and find the bosch plugs are better in 2 stroke motors as i have had to rebuild several 2 stoke bikes with holes in there pistons all without fail were fitted with champion plugs,i have never had a hold piston rebuild when bosch plugs have been used,worth remembering dont you think

[majokebu]

on the same not i am a machanic by trade and find the bosch plugs are better in 2 stroke motors as i have had to rebuild several 2 stoke bikes with holes in there pistons all without fail were fitted with champion plugs,i have never had a hold piston rebuild when bosch plugs have been used,worth remembering dont you think

im intrigued,,,
u are sugesting that the champion plugs are to blame ,,
how come ?? im not a mechanic,, but as an ex biker who rebuilt
many a bike engine,, and diy my outboards servicing and repairs,,
ive never heard of plugs being the cause of holed pistons

[ChrisP]

I don't like Champion but they are specified as OEM on Johnson outboards hence the number. Much prefer NGK or Bosch.

[MerseyAngler]

NGK personally:clap3:

[bigfish]

If it's a twin cylinder 2stroke you've got the NGK plug is BR7HS (standard) or BR7HIX (iridium)

[andyhunt]

thanks guys, i have found that the previous owner used BR9HS-10 plugs but i thought they may run a little hot. but i suppose they may be needed to run well just don't want to burn anything at the top of the piston if you know what i mean.
might try her with something a touch cooler and see how it goes.
thanks all.

[MerseyAngler]

Seem to remember the heat range number is opposite with NGK and Champion as in …. the higher the number with Champion is a hotter plug the higher the number with NGK is a colder plug and vice-versa … worth remembering don’t just look at the number and think they are the same like for like!