Just picked up a 1989 thompson daytona 270 with twin 3.7 liter 4 cylinder merc cruiser motors. in nice shape needs some touching up but for $4500 bucks with a trailer I couldnt pass it up. I want to give it a complete tuneup, change all filters, oil in drives and motors ect..how do I change the oil in the drives? Are there any other filters I can change anywhere? I want to get this boat ready for the water and I dont want to miss anything. All the boats I have had are older so I am a little lost but I want to make this boat last so what is the proper matinence for a boat that has not been used consistantly in a couple years. Also I believe the boat is not fresh water cooled however there is a bucket for water in the engine compartment. i dont understand what the water is for. Any help getting started with this boat is greatly appreciated. thanks
Change the drive oil by removing the drain plugs one is the on the bottom, one is on the top. (of the drive) If you have resivoirs, remove the caps so the oil can drain out. To refill, fill from the bottom plug until the oil starts coming out the top plug. Then replace the top plug and gasket, (before removing the oil filler hose) Then the bottom plug and gasket. finally, top off the resivoir bottles.
As for fresh water cooling, yes, your drive does use fresh water. Whether to cool the whole engine, or cool the heat exchanger on a closed cooling system.
A couple of photo's would interest me, especially concerning the "bucket".
"Fresh water cooled" means anti-freeze circulates thru the engine in a closed system much like a car but cooled by a water-cooled heat exchanger rather than an air-cooled radiator. Raw water from the lake is used to cool the heat exchanger.
"Raw water cooled" means lake water is circulated thru the engine, no heat exchanger.
Maybe the bucket was there to test something in the cooling system. It should not need a bucket if all is well back there.
Also I believe the boat is not fresh water cooled however there is a bucket for water in the engine compartment.
The actual, correct, and more accurate term is "Closed Cooling". And all 470s (3.7s) were closed cooled.
The fact that you have a bucket of water in your engine compartment can not be a good sign.
If your are 470's are both in good shape, you are lucky. I would suggest you do the above mentioned search and start learning the known issues. Most of the problems can be prevented with pro-active maintainance.
ok here is the update. I launched the boat last night and took my 60 mile journey to my dock slip. Everything went well till about an hour into the trip the one engine started getting hot. It looks like it is dripping antifreeze from the front of the motor. Its dripping by the oil pan so I have to find that leak. Anyway I added some antifreeze and that motor runs great. The second motor had some other issues. The temp gauge stayed low the whole time and I ran it for about 3 hours so I am hoping I am good with that. The issue is when the motor was hot It had trouble turning over and wouldnt idle for long enough for me to get it in gear. I was afraid that it may have been running hot and my gauge was broken however running it for an hour and half after that I think would have done some damage if it was that hot. I thought it may have been the timing however would this cause the boat to turn over hard. it seemed like a dead battery and at one point it wouldnt turnover at all. I let go of the key and started again and I got it to fire up. Could it be the timing and maybe a carburater issue causing it not to idle. i thought if the timing was so far advanced that is caused the engine to not turn over, it would raise the rpms and keep it from stalling in idle. do I have two seperate issues here? I am going to try and start the boat while cold today and see what happens. thanks
Leaking AF is definately cause for concern, these engines are know for faulty cam seals that allows the coolant to leak into the oil. You need to check IMMEDIATELY, that you are only leaking AF externally, if it is leaking internally and you continue to run it, you will be shopping for a new engine.
It also sounds like there are some basic maint. items that need to be addressed. Full tune-up, seawater pumps/impellers, carb adjustments/rebuilds, possible bad or water contaminated gas.
If you're going to keep that OMC Cobra, please for the love of everything good in the world, get an OMC factory service manual. Not a Clymers, Not a SELOC. You can find them on eBay.
I dont think its faulty cam seals because I changed the oil and filters already and found no water or AF in the oil. I can probably rebuild the carbs and change the points to get the motors running smoothly. My main concern right now is finding where the AF leak is coming from and trying to figure out why the motor is so hard to turn over when hot. I will take some pics of the leak and see if I can get some answers. thanks
I dont think its faulty cam seals because I changed the oil and filters already and found no water or AF in the oil. I can probably rebuild the carbs and change the points to get the motors running smoothly. My main concern right now is finding where the AF leak is coming from and trying to figure out why the motor is so hard to turn over when hot. I will take some pics of the leak and see if I can get some answers. thanks
there is two seals the first will fail and coolant will come out of the weep hole indicating the seal has failed. Eventually the second will fail then you will get coolant in the oil. This has been covered in great detail at a 470 specific fourm www.breezeworks.net
a picture is worth a thousand words.... here are a couple pics. I circled the exact spot of the leak. The Anti Freeze is pouring out pretty good. It looks like the water pump or something.
bought a new boat...
Linear Mode
