1972 50 HP Johnson on 15' Seastar tri-hull

[dicktaber]

First timer--having a lot of fun and learning a LOT thanks to all of you. Couple of boat/ motor questions--<br />1. not charging battery--ideas? Doesn't seeem to discharge much either, though...does the CDI generate spark and only use the battery for starting?<br />2. prop "thunks" into forward when I shut off key. I'm told a diode failure will produce this. Sierra doesn't carry the diode pack--where do I get one and where does it go? A mech at a boat shop showed me what it looks like (called it "monkey balls" which was very descriptive) and it was attached to the power pack, but my motor doesn't seem to be so equipped.<br />3. only getting 25 mph--is this about right?<br />4. no tach (looking but have to spend $ on other things first..) prop is 13.75R15..boat is rated for 1700 lbs..does this sound right?<br />5. is hull constructed of foam under fibreglas...what is under the carpet? can I check for soaked foam? Thanks in advance for all your help and knowledge. A pleasure being in such fine company.

 

[rocks beware]

Re: 1972 50 HP Johnson on 15' Seastar tri-hull

Hey Knot2much(nice name),<br />It's looks like we have something in common. I just bought myself a 1972 Seastar 17' tri-hull. I thought I was the only Seastar owner left! It's got a 85hp Johnson. It's my 1st boat, and it needs some fixing up(paint,carpet,tune-up,etc.) It'll be a project for my wife & I - we won't put in till next season. The only problem I've encounterd so far is a bit of rot on the floor(deck). Still trying to find out the best way to replace this section. I too am worried about the rest of the floor and beneath. Please keep me informed as to any info or problems that you may come across and I'll do the same. I just got my tax check so I'm going to pick up the boat in a few days and I'm bringing it directly to the shop to have boat,motor, & trailer thoroughly checked out & readied for winter. Also, do you or anyone have any info or backround on Seastar boats? I've only seen one other one. They seem pretty well-built. Good luck w/ everything.<br /> Rocks<br /> (this board is awesome)

 

[JasonJ]

Re: 1972 50 HP Johnson on 15' Seastar tri-hull

I was where you are at a few years ago. I purchased my 17 ft 63 Pacific Mariner for a whopping $100. It had the Homelite 55 4 stroke 55 horse motor. After replacing the floor, putting new seats and carpet, as well as rebuilding the carbs and lower unit, I could, at best, get about 22 mph out of the boat. I recently got an 85 horse Merc, and that bumped me up to 31 mph. You should make sure the engine is healthy, then take her out, with the tach that you need to buy, and make sure she is running in the appropriate rpm range for the engine. Only then can you decide if you need to reprop or get a larger motor or whatever. In the end, top speed isn't that important anyway, its a good cruising speed that matters. I find that I cruise at around 22 mph, its the most fuel efficient for my setup, gets me where I want to go (am never in a huge hurry anyway), and the motor isn't being stressed out too much. Anyway, good luck. Just for perspective, I am only into my boat for about $1200, including the recent Merc purchase, so the deals are out there....