Spark plugs

Owleyes

Recruit
Joined
Nov 25, 2017
Messages
2
1985 Force 85hp outboard
I have replaced all the fuel lines, installed water separator fuel filter and rebuilt all 3 carbs. Motor seems to run fine. Boat is me to me but I think it is not getting as much power as it should. 28-30mph.
I replaced all 3 surface gap spark plugs but
The #2 spark plug looks like it was just taken out of the box. The other two appear as you would expect them to.
Pulled off the #2 plug wire and I do have spark but does not seem as bright and powerful as the others...
Do I have a bad plug wire/coil ??? Can I swap them around and see if I get the #2 plug to look like it was firing???
PLEASE any ideas, I am very new to this but am learning allot.
Help
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
17,923
First thing, a compression test.

Yes swap the leads around and see if that makes a difference.
The 1985 had plug in leads and that makes it easy to test.
Just remember where you started so they can be put back right.

​If you have weak spark, it could be the coil's going bad?
​I haven't seen but 3 bad coils in 35+ years???
Check the grounds and ground leads.

Since it's #2 the packs each fire 2 plugs.
​Since you only have 3 the secon one on pack 2 just hangs there unused.
​Try switching the packs and see if fire on #2 comes back.

​If nothing helps? the trigger leads might be loose and not making contact. Clean the connectors.

Then check the stator.

​Outboardignitiondotcom has test procedures.
​You can do some basic tests with a regular analog meter.
​the more complicated need special equipment.

28-30 could be all your gonna get if your motor's mounted on a bigger boat??
What size boat??
Rpm's???
Pitch prop?

Oh yea, Welcome
 

Owleyes

Recruit
Joined
Nov 25, 2017
Messages
2
Hey there
Thank you so much for the response.
Great suggestions. Did compression test and all are with in 1 psi. Swapped around the#2&#3 and is ran but it seemed a little rough. Can it be firing intermittently?
Swapped them back again and it seemed rough at first then smoothed out.
The boat is 17' Bayliner bas boat. Don't know prop pitch but I will find out. No tack.on boat...don't know RPMs.
I will try to check the other suggestions. I will let you know what my results are. Back soon
Thank you very much.
 
Top