Fuel economy of 88 v20 w mercruiser 165

[Rscottdds]

My son just got one of these. Any idea of the range? I think it has a 60 gallon tank.

[Rscottdds]

Someone has to have this boat and engine package or something similar. Any guesses as to the fuel burn?

[THEFERMANATOR]

If driven easy and conservatively, I would think 3MPG is easily obtainable. That 4 cylinder 3.7L was a good engine, and didn't seem to bad on fuel from reports I have seen. So if you go on the side of safety leaving some reserve in the tank, your range should easily be in the 125-150 mile range(but I think I have seen where some here with that combo have reported almost 180 miles of safe range).

[Rscottdds]

Thanks for the response. I'm pretty sure its a 6 instead of a four though. Could be wrong (just did a quick run through the boat when my son brought it by) but I'm pretty sure its bigger than a 4 cylinder engine.

[THEFERMANATOR]

Unless somebody changed it out, by 88 MERCRUISER was using the 3.7L 4 cylinder. I believe the straight 6's stopped around 78 or 79. The 3.7L 4 cylinder is a big 4 as it is half of a FORD 460.

[Rscottdds]

Ahh! You are right. Just checked and its a 4. The boats been sitting for 4 years. What should he do besides the obvious (plugs/oil/new gas) before trying to start it?

[THEFERMANATOR]

Wouldn't be a bad idea to also rebuild the carb as it could have sat and got moisture in it. And if it still has points in the distributor get an IGNITOR electronic conversion to go in it.

[smokeonthewater]

new impeller n oil for the drive. Pull drive, grease ujoints, inspect gimbal bearings, adjust engine alignment (requires alignment tool $25 on ebay) replace bellows before using boat and consider trim senders at the same time if they are bad. and a new lower shift cable is often a good idea

[spareparts]

what they all said!

[dan4836]

I have an "82" with the 470. After re-doing the head gasket and every part of the cooling system (boat sat for 11 years) the engine is running perfect.

What I found about the 470 - Some people don't like them and some people love them. I found these engines were put in a lot of boats throughout the 80's and early 90's and many people neglected the general maintenance needed.

The 470 is a great match for the V20 but will not be as fast as the outboards in the 150 plus range. Fuel economy should be at least 3MPG at optimal cruising speed. I did not do any test on fuel consumption yet, but I am hoping to burn 5 GPH at 20 knots. I think it will come in closer to 6GPH but we will see.

I am turning a 14 X 17 aluminum prop. In a light boat, I am getting 4800 RPMs - I might switch to a stainless Mirage in the same size.