1985 bayliner 2.1 volvo penta I/O overheats

[jla11868]

i just bought this boat and it overheats within 5 min i took the thermostat out just in case it was stuck and still overheats i do not know much about I/O's can someone tell me where the water pumps are and where does the return water spray from? i think it has 2 water pumps one with lake water and the other has coolant.

 

[ajax5240]

Re: 1985 bayliner 2.1 volvo penta I/O overheats

Check the impeller that is in the pump housing that has the 2 copper pipes coming into it. Get a new thermostat and put it in. Take the rubber hose off the impeller inlet (the one on the carb side) and pump water into it with a garden hose, see if water comes out anywhere other than the inlet holes on the bottom of the drive. If it does, you need to fix that or it will overheating everytime you get on plane. Good luck!

 

[leakywire]

Re: 1985 bayliner 2.1 volvo penta I/O overheats

The sea/lake water pump is the one on front of the distributor with the copper pipes like ajax described, there should be 2 10MM and 2 8MM screws involved, the pipes are retained by 10MM screws and a bracket the holds both to the pump body equally, under the cover held by the 8MM is the actual rubber impellor much like the outboard motors use, be careful not to lose the shaped key as you take the shaft and impellor apart to inspect for clogged waterways from rubber swarf left by a broken blade. The drive key must go into the aux shaft gear properly or you will not be able to put the pump back on the front cover - it is important to flush thru these passages as the broken rubber parts will obstruct the flow of cooling water to the heat exchanger and the exhaust manifold causing the overheating, the engine coolant must be full in the tank over the camshaft.

 

[Eddie Ray]

Re: 1985 bayliner 2.1 volvo penta I/O overheats

Hey, I have the same boat. If yours is a trophy? Any way ,the water will come out the exhaust. Which is the kinda triangular opening above the prop. There are two pumps,one for engine block. One is a raw water pump. The maual warns against running with out the thermostat? We do it with cars all the time? But do be careful if you do that. There are lots of places where you can have a small air leak in the raw water system. Even a small air leak can cause the pump to not work well. The fitting the other guy mentioned is often the problem. It can clog or even break. I have already replaced mine. The impeller is often the problem too. It is easy to replace,not too pricey. I have had some leak issues with the lines on this pump. Last time I took them off ,I used some gasket maker to help seal them. No problems since.
I have a twenty two foot trophy boat. She is slow,but steady. And a pleasure to fish from.
If I can help in any way just let me know. I am pretty good with this boat,as I have redone most of mine.
Hope it works out for you.
Eddie

 

[jla11868]

Re: 1985 bayliner 2.1 volvo penta I/O overheats

thanks guys it was the impeller i also replaced the thermostat now the carb seems to load up at times the guy i bought it from said he recently rebuilt it should i do it again

 

[ajax5240]

Re: 1985 bayliner 2.1 volvo penta I/O overheats

Before starting to mess with the Carb, double check your points, dwell, and timing. The ignition being out of spec can seem like a carb issue. If it was just re-built (correctly) it would not be the first place that I would check. There are not a lot of adjustments on these carbs, so it being out of adjustment is not very likely.