Spark Plug Question

[Bill Willette]

The 100 hour mark is up on my 90HP mercury and I need to replace the spark plugs. I've done everything else I need to for the service interval. The mercury website shows the following plugs for the motor:

BUZHW-2 (resistor $12-$13 bucks each)

BUHW-2 (non-resistor $3-$4 bucks each)

The motor has the resistor (BUZHW-2) plug installed currently. The question is do I really need to buy the resistor plugs? Obviously I'm hung up on spending $9 bucks for new plugs instead of $36 bucks. The website didn't give any application notes for the plugs either - it just showed both. What ill effects would I have from the non-resistor plugs. I would think without the resistor you would have noise in the say 1000hz and up range, this shouldn't affect the 200hz depth finder or a GPS way up in the GHZ ranges. Maybe it would affect my emergency VHF radio, but I'd probably have the motor off to use it.

Which ones should I buy?

 

[Bruce Yeaton]

Bill, stick with the BUZHW-2's! I ran the non-resitor type plugs before in my 90, motor ran like crap. The 90 does call for these plugs.

 

[Marke Cicero]

I think it depends on what year your motor is.



I know that Andy Z. has a 99' or 2000' 90 and his requires the resistor plugs.



My 90 is a 2001 and I do not require the resistor plugs. Merc must have changed the specs between the two models years or something.

 

[Bill Willette]

Thanks for the input guys.

I put the BUZHW-2's in today. The dealer said I need

to use the 'Z' version of the plug because my motor has a

CDM ignition. The 'Z' plugs have an inductive resistor that is required for the CDM. They told me if I ran a regular plug the motor would misfire and have poor performance. I took their word for it and paid up. Next go around I'll buy them from sparkplugs.com to save some bucks. I also changed the lower lube, greased all fittings, and replaced the fuel filter. Now if I can just wait another month or so Welaka and Salt Springs should be happening. My neck of the St Johns has slowed down, I haven't had much luck since the end of September, but that's why they don't call it catchin'

 

[TOMMY RICH]

Don't go to the dealer!!!!! Go to Autozone or Advance Auto and get em' for about $5 a piece...

TEE