Hello All,
I had my '87- 241 Liberator out yesterday and I had some problems and I don't know what happen. Maybe you guys can give me some incite before I have to go tearing it all apart or going to the marina. I just purchased this boat 6 weeks ago and the only problem I have is it just seems to take too long to get on plane. It has a 454 magnum with an alpha one drive. I do not know the prop size at this time but can get it if needed to get answers. Now the latest problem, as I was traveling across the water everything looked "gauges" okay. All of a sudden I heard a noise in the motor looked at gauges and the temp was above 190, oil pressure was down almost all the way and so I stopped and temp dropped to below 190 and oil pressure came right up. So I headed back to dock at a slow pace. As I gave it more throttle it seemed okay so I pushed up the throttle to full to see what it would do, as I did the motor tacked up after I hit about 25 on the speedometer it was like it kicked out of gear and the temp started to go up again. so I slow paced it back to ramp and I left it idle and temp dropped to 160 and had good oil pressure. Can you guy maybe give me some feed back. This is the first inboard I had, I always had outboards so I'm lost for now. I am also looking for a owners manual for this boat if anyone knows where I can find one or has one I can buy a copy of. I have a repair manual for the motor but I want the one for the boat. Thanks all.

Hard to really follow what you're saying is going on. What i am getting out of that, is that the motor is getting HOT. Lack of water flow, like a bad impeller, clogged oil cooler, etc, will starve the engine for cooling water. The engine will get hot, and so will the oil. As oil gets hotter, it gets thinner, and psi falls off. Hopefully it didnt do internal damage to the engine.

As for why it felt like it 'kicked out of gear', could be a slipping prop hub. The hub inside the prop can be slipping, and make it feel like a car when the tranny slips. Engine revs but boat doesnt accelerate.

My thing is all this happen at one time, Boat ran perfect the week before and the next time out all these problems. Boat did not overheat just temperature got higher than normal on the gauge, and oil pressure was low. after I left it idle temperature dropped below normal to about 160 and oil pressure raised back to normal on gauge.

usually these things do happen all at once. 190* on the water temp gauge, can be quite hot for a marine engine. Even though its showing 190* water temp, your oil temp could have been much hotter. A thermostat not opening can cause issues also.

Did you have a good amount of water dumping out of the tail pipes?

Looks to me to be a fair amount. It is a steady stream along with some steam. The guy I bought the boat from told me it had a 190 thermostat. Again this is my first boat of this type. Do you know any video I can see to compare the output?

1987 454 Mag should have a 140* thermostat.
http://www.perfprotech.com/store/ass...),938-140.aspx

There were 2 different design thermostat housings for that engine (old & new) so the one in the diagram may not be the same as yours however they both used the same thermostat.

Do you know what wt oil is in it? Should have at least 40wt.

What is the max RPM's at WOT. Should be about 44-4600. Need to find out the pitch of the prop. That may be what's making it hard to get on plane. My quess that boat would need a 21P.

think i would check drive hub on flywheel also.

change the impeller in the drive water pump. put proper thermostat in it. borrow a 17 thru 21 pitch prop. 17 will rev too high, but boat will jump on plane like you won't believe. 21 is probably optimal for that boat. if it still slips, borrow another prop. if slips with 3 diff props, you hafta pull motor and replace coupler. but it takes 5 min to change a prop, so be sure it isn't prop hub slipping.

I will change Thermostat to 140 hope running the 190 didn't do any damage, no way to check oil weight so I will just change that too. put in a new impeller. and I will have to see about getting a prop from somewhere. There is an old guy with a shop not too far away maybe he will rent me one, won't hurt to ask. I'm in Cleveland Ohio and not a lot of days left before I have to put it away for the winter. As far as RPM's at WOT I can't answer that because I don't remember what it was, hey guys thanks for helping me I'll try not to be much of a pain in the neck by asking questions. But I have been without a boat for a few years and the last one I had we had a storm and a barn fell on top of it and a barn beam went down the side. I still have it and would like to fix. I had it since I was 16 years old and I am now 53 years old.

most 241 libbys are not speed demons to get on plane, but with correct prop they can get on plane in a very normal amount of time. I am assuming your boat has yabs? some of these did not. if not they will make a big differance. And if you have them make sure you are moving them in the correct direction. the button on my libby were backwards fromthe way they moved compaired to every other boat i ever had been on. took me 6 months to figure it out. some had the wires 86in the wrong spots on the switches. most ppl find depending on what there gear ratio is that a 19 or 21 pitch props works best for them. mine surrently has a 21 mirage 3 blade. i think it came from the factory with a 19. mine is a little differant it has a bravo 1 drive from the factory. my prevous 86 241 had a 454 alpha combo, i ran a solas amita 4 19 pitch 14.25 dia and seemed to work very nice on the boat. http://boatpropellers.iboats.com/Mer...t_id=566573686 this is where i got mine. for 100 bucks its worth a try. i just order a chad hill pleasure 15 for my current boat

the heating issue does sound thermo and impellar related. they can go bad at anytime. you probably dont know how old it is and i would replace it at least every other year. they are the cheapest and easiest place to start first before going way too far. You could check to make sure to cooler is not plugged by following the intake water hose around it will go through the cooler first then up to the motor. It is about a 1 inch hose. when the motor is cold and sitting on trailer or dock. take this hose off motor and have someone start the boat and physical watch the water coming out of hose. Now dont do this long motor will get hot, water will get into buildge, stay away from moving parts, use some common sense, not saying you wouldn;lt but some ppl either dont know or dont think just trying to be safe. if good water comes out after swtiching impellar your cooler is not plugged. But i dont think it is. sounds impellar to me.