1984 vip 19' with mercruiser 140hp 3.0. questions!

[trabich]

I had just bought a 1984 VIP ski boat that is in very good condition. I am needing to replace the plugs in the 3.0 140 hp mercruiser. What plugs are recommended for this motor and what would the gap be?

Also, what is the recomended prop for this boat? It was a dog getting out of the whole and on plane so I installed the StingrayII hydrofoil. It does get out of the whole easier but I do notice a decrease on the top end. The prop that came on the boat is a 21 pitch. Someone had told me to go with a 17 or at most a 19. Does this sound right?

 

[tupperj]

Re: 1984 vip 19' with mercruiser 140hp 3.0. questions!

Trabich,

I've got an 18ft SeaRay of the same era with the 3.0.

Plugs: AC MR43T - Champion RV15YC4 - NGK BR6FS
Should be able to find one, or cross reference.
I like NGK's but others have different opinions.

On the prop, mine has a 14.5 X 19 on it, which I think was stock.
Can't give you any performance info, as I'm still trying to whip the engine into shape.

Enjoy!
Paul

 

[trabich]

Re: 1984 vip 19' with mercruiser 140hp 3.0. questions!

Thanks Paul. I don't know what the guy I bought this boat from was thinking. There is a 21 pitch on the boat now and he had a 23 pitch under the seat. I've been going through this motor as well just trying to get it tuned in. I have noticed that from the first week I took this boat out it was hitting about 40-45 mph. Now for some reason I am only getting 30 - 35 mph. Trying to figure that out now.