Running on Wrong Plugs

[jefisherjr]

The boat I bought last Spring came with a 1994 225 3.0 L. I had it tuned up by a Mercury mechanic recommended by a long-time boating neighbor. I recently noticed that the new plugs he installed are NKG BU8H surface gap type plugs. However, the owners manual and shop manual state that the motor uses NKG BUZ8 H-N-10 plugs with the more common electrode setup. The motor seems to run fine with the BU8Hs, but will they cause any future problems? Don't want to be left stranded somewhere far from home base.

 

[jefisherjr]

Re: Running on Wrong Plugs

Correction. The new plugs are NKG BUHW, not BU8H as previously posted below. The OEM plug is NKG BUZ8 H-N-10. The question remains, am I going to experience any problems with the BUHWs?

 

[lilmandavis]

Re: Running on Wrong Plugs

I wish I could run surface gap plugs in all my engines... I have only fouled out one set in all the sets ive ran. Pulled em out twisted them back and forth on a piece of braided rope and cranked the engine over and bam, fired right back up. as for the heat range you should run on yours im not sure but i would stick with those ol trusties!
i run a little thick on the oil to gas ratio as well. I have a 1400 and a 1500 inline a 800 inline and a few small tillers.

 

[Chris1956]

Re: Running on Wrong Plugs

I would run the correct plugs. Make sure the recommendation has not changed.

The BUHW was a standard plug for Merc Inlines for many years. My '93 Merc 135V6 runs the BU8H plugs, but I would like to put some conventional plugs in it.

BTW - I have always had good luck with the conventional plugs in the OMC outboards I've owned. The never foul when the motor was operating properly