Mercruiser 228 still overheating

[othelloears]

My raw water cooled mercruiser 228 (alpah 1) is still overheating at high speeds. Cools down quickly when idling. Engine starts and runs properly. No water in engine oil or drive oil.

I have replaced:

1) Water pump (incl base)
2) transom hose
3) Engine water pump
4) manifolds
5) risers/elbows
6) thermostat

Question: Which elbow gasket do I need? I am using one with 2 small holes aiming for and aft. Could that be problem?

 

[Don S]

Re: Mercruiser 228 still overheating

What is your wide open throttle (WOT) rpm? If you are over propped, it will cause an overheat at high speeds.

Could you post a picture or two of your overall engine cooling hose configuration and thermostat housing?

 

[othelloears]

Re: Mercruiser 228 still overheating

Good thought but no. WOT is within range and I had prop for several seasons before started overheating.

Not able to post picture. I do have tee/check ball system and trying that next.

Real interested in the riser gasket with 2 small holes. Does that seem right?

 

[Don S]

Re: Mercruiser 228 still overheating

Why can't you post pictures? It's simple to do. http://forums.iboats.com/showthread.php?t=468676

 

[othelloears]

Re: Mercruiser 228 still overheating

Why can't you post pictures? It's simple to do. http://forums.iboats.com/showthread.php?t=468676

Not at home and boat is still under winter cover.

No thought on elbow gasket without pictures?

 

[Don S]

Re: Mercruiser 228 still overheating

I do have tee/check ball system and trying that next.

Real interested in the riser gasket with 2 small holes. Does that seem right?

The check ball system wasn't used on the 228. Do you have center rise manifolds or log style?

Was the boat working fine, no overheat then just suddenly start overheating, or was work done, then it started overheating?

 

[othelloears]

Re: Mercruiser 228 still overheating

I have a 1982-1984 228 (305). I do have a Tee/check ball system.

Boat was overheating early last season. I've posetd my dilema several times on thie. I first replaced thermostat, impeller and pump and was fine for a couple weeks. Replaced manifolds (center rise) and elbows and was good for another couple weeks. Replaced what I thought was kinked hose in gimbal housing and was good for an hour and started overheating again. Thats when I put boat away last season.

Can't explain it how it resolves and comes back. that's what makes me think its the tee check valve which I've read about.

 

[Don S]

Re: Mercruiser 228 still overheating

I'm not saying you don't have it, I'm saying it was not OEM on the 228's. That is the reasons I asked the questions I did (that didn't get answered).
Since you still have the problem, your previous threads don't seem to have hit upon the cure.

So, if you could, please answer these questions from above.

1. Do you have center rise manifolds or log style?

2. Was the boat working fine, no overheat then just suddenly start overheating, or was work done, then it started overheating?

 

[othelloears]

Re: Mercruiser 228 still overheating

1) One day started overheating before any work done
2) Center rise manifolds

 

[Don S]

Re: Mercruiser 228 still overheating

The riser gasket is fine.