spark plugs

[oldsupra]

which plugs should i use in my 1985 ts6m(351w) the champ RV12Yc or the hotter rv17yc the auto guy said to use the rv17yc and the boat runs a little rich so i was thinking the hotter plug would help????

[csuggs]

I don't know about you , but I always try to go with the OEM parts. I bought mine from www.skidim.com
My Supra manual (86 Sunsport Skier) calls out Autolite BTF3M or Champion F10.18MM (never heard of that one) for the 351.

;)

[Irish_Jack]

Hey man,
Technically you should only use the designated heat range for your engine application. The heat range is set up for your timing curve, fuel curve, and running condition. In my professional opinion it would be better to solve the drivability issue and re-tune the carburetor. You will get a better result.
Besides, running a hotter plug can likely result in predetonation, run-on(deiseling), or pit up the top of the pistons...

[DKJBama92Mariah]

Do not deviate from the factory specs. It's that simple. You can't fix a rich mixture by changing plug heat range anyway. Also, you shouldn't use auto plugs, they will corrode quickly in the 100% humidity of your bilge.

You can buy the PCM 8 plug set from Discount Inboard Marine ("skidim") for $24 here http://www.skidim.com/prodinfo.asp?number=RP030002 . If they're old (>5yrs)you should also consider replacing plug wires, distributor cap & rotor, points, and condenser while you're at it. That's pretty much a complete ignition tuneup.

Don't forget to coat the spark plug threads with anti-seize before installation. This will aid in removal the next time around.

As for as your running rich problem, how rich is "a little rich." Are you just going by the sniff test of the exhaust?

If so, the tuneup should help a good, but part of it is just the nature of a carbureted boat. It's usually the worst while warming the engine up.

[csuggs]

OldSupra -

I agree with DKJBama in that a tune-up should go a long way, or is at least a good start to resolving your troubles. However, if you are thinking about replacing points and condensor, I would seriously consider converting to an electronic ignition. It's a simple conversion and will save you headaches in the future! skidim.com also has these parts (I got mine on clearance!)

[DKJBama92Mariah]

OldSupra -

I agree with DKJBama in that a tune-up should go a long way, or is at least a good start to resolving your troubles. However, if you are thinking about replacing points and condensor, I would seriously consider converting to an electronic ignition. It's a simple conversion and will save you headaches in the future! skidim.com also has these parts (I got mine on clearance!)

Good advice. I would not have a boat with points.

EDIT: Looks like that conversion kit is still on clearance. http://www.skidim.com/prodinfo.asp?number=RP173071A

[oldsupra]

i have the pertronix and new cap and wires as for running she runs peeeeerfect just a tad rich at idle -the plugs are for a 1975 ford 351w but non marine the book says rv17yc but i dont know if the heat range is the same for marine

[Irish_Jack]

Agreed, Just go with the specified spark plug and adjust the idle mixture screws... You will be good to go:cool:

[oldsupra]

i just changed the plugs it had oll rusty ngk(junk)v power ur5 in it-- WOW IT RUNS BETTER NOW THAN MY NEW 08 CARVELLE INTERCEPTOR