Best spark plugs? And what else should I do?

[Newbie@boats]

I have an 86 mercrusier "470"

I want to change the spark plugs in it and I would like to put in the best ones I can get.

Anybody have a part number or any recommendations?

What else should I do to make sure I have a problem free summer?

 

[Don S]

Re: Best spark plugs? And what else should I do?

Which spark plug depends on the distributor.

http://forums.iboats.com/attachment.php?attachmentid=148212&stc=1&d=1337812967

What else should I do to make sure I have a problem free summer?

With a 470, PRAY a lot.
Seriously, without knowing the history of what has been done, impossible to say. One thing is for sure, you DO NOT want an overheat. new impeller yearly is a good thing, make sure the bellows are good. Keep an eye on the oil and coolant levels and make sure you don't see antifreeze in the oil. Keep an eye on the voltage. If the voltage gets too high with the OEM charging system, you will cook your batteries.

 

[Newbie@boats]

Re: Best spark plugs? And what else should I do?

Thanks for the info Don, the previous owner was the original owner.

The water pump was done, and they speedi sleeved/sealed the shadt(not sure which one) to prevent further failure I guess.

The motor was always well taken care of, oil and coolant both look good full and clean, there was a regulator or solenoid replaced at one point which cost around 300$ not sure which one or what it did I'll have to look at the paper work for that.

The voltage gauge seems to be at about 13/.5 usually, all the gauges work in the boat and I always keep a close eye on the temp gauge.

I had a 470 a few years back and I couldn't figure out why it kept over heating, I hope I have zero trouble with this motor.

Should I do the air cleaner also, or just clean it?

 

[achris]

Re: Best spark plugs? And what else should I do?

Use either NGK or AC-Delco plugs, NEVER champion....

The 'air cleaner' is a flame arrester, and not a filter as such. Just wash it out in a suitable solvent like petrol (please be careful) or meths.

I have fixed quite a few 'it's always overheating', when the engine cooling system was fine and the leg impeller and housing were all new, by replacing a leaking water pocket cover and gasket in the bottom of the top box of the drive.... And it's quite easy to detect... Just run a section of clear hose in the water feed from the transom... Run the boat normally and have a look at the water in the clear hose.... See air bubbles? Water pocket cover leaking....

Chris......

 

[Newbie@boats]

Re: Best spark plugs? And what else should I do?

Thanks Chris.

I'll change my plugs out and clean that out and be done with it. But if the boat does start over heating I'll be coming back!

Can I ask...what shaft was speedi sleeved? Will I have to worry about failure again on that?

 

[achris]

Re: Best spark plugs? And what else should I do?

There's a few shaft that can be sleeved, it depends on which one was grooved... My experience with those sleeves it that if they are put on right, they last a VERY long time....

It's most common to sleeve the cam shaft water pump seal surface (only on 470s), the drive unit yoke seal surface, also the drive unit water pump seal surface on the lower drive-shaft and the seal surface on the end of the upper drive-shaft.

I can't tell which one was done on your engine unless you have a receipt with the speedi-sleeve part number on it...

 

[Newbie@boats]

Re: Best spark plugs? And what else should I do?

It was the cam that was speedi sleeved, for the waterpump.

I just hope it lasts.

The PO said it was dripping coolant from the weep hole so he had the pump replaced and the sleeve was installed, which I believe was done properly, the motor and out drive are SUPER clean. They look like they are on a brand new boat in a showroom.