Need help with tank size for 17' angler

[aiezzi]

I need some help guys, I just picked up a 87 angler 17' center console the tank under the sole was pulled by someone and never replaced they just ran it from a portable 6 gal tank. Now I'm
Looking for some advice on the size, I'm looking at poly tanks, the few I have found to fit its coffin is a 12 gal, 17 gal, and a 25 gal tank. I'm leaning towards the 17 gal tank but also don't want to be stuck in the situation of being out and having to head in early from lack of fuel. The boat is currently powered by a 97 mercury 50hp four stroke, but the motor is supposed to have low compression in one cylinder which I have not yet verified, if that's the case I'm looking at replacing with a 70-90 hp two stroke. So can anyone tell me what a common size that people use for the 170 when they replace it?

[RickK]

The tank in my 170 was a 27gal.

[Capt. Bob]

Yes, 27 gal is the listed size.


Any reason not to go back to that size other than cost?

Aluminum, properly installed will last a long time.

Here's some dimensions.
http://classicaquasport.com/smf/index.php?topic=11420.msg112278#msg112278

Phil, at Alloy (he's made a ton of Aqua replacement tanks). Note the 2 gal increase.
http://classicaquasport.com/smf/index.php?topic=11420.msg112285#msg112285

Great write up on your model.
http://classicaquasport.com/smf/index.php?topic=11420.msg113572#msg113572

Plenty of installs in the fuel section to guide you. Many of us have replaced tanks so we can help with all manner of opinions and ideas.

Good luck.

[wingtime]

I'd go with the 25 gallon.  You don't have to fill it up all the way.  A 90 HP two stroke will probably burn 9 gallons an hour at WOT.  Of course who runs around at WOT.  So lets say you burn 6 gallons an hour at cruise.  The 25 gallon tank will give you a three hour range with a hour reserve.

Of course I've never even come close to using even half a tank in my 170 that has a 90HP Ocean Pro on it.  Of course I don't usually take it very far since I use the 245 for long trips.

[aiezzi]

Well the main reason I'm considering poly is the price, single father with child support and my son being a year old doesn't leave me with much speanding money lol, so I'm just trying to get it on the water correctly, fix any other issues and not be to broke doing it.

[RickK]

Wing is right about the burn rate.  My 90 burns about 6gal/hr at cruise (30mph) - I premix the oil so I always put in multiples of 6 gals when I fill up to make it easy to calculate 50:1 mix.  1 quart is good for a 12gal fill.

[aiezzi]

Well that's why I came here because I know you guys are extremely knowledgeable about his kind of stuff, and as my luck would have it, i think my 50 hp mercy is still good, I have to order a starter solenoid but my compression test tonight cranking the motor by hand was all 4 steady at 90, so that leaves me to believe that with the motor turning over by the starter would give it higher conpression

[RickK]

I think compression is compression - hand crank vs with a starter should be the same.  I do think you are under powered on the boat though.

[aiezzi]

Well let me reword that lol I got it to 90 on each one and that's about all i could take lol. Yes it is definitely underpowered but if it runs and the compression turns out to be good across the board, then this winter I will look for another motor more appropriately sized for the boat, and I'll list the four stroke for sale