AQ151c

[T1ony]

Hi guys, new to this site, I have a pair of AQ151c's, my problem is that my starboard engine overheats, its ok at 6-10 knots but if I give it some welly 17knots or more within about 3mins it over heats then I slow down to let the engine cool for about 10mins, but now the engine just cuts out, I have checked the intake connected hose and pumped overboard, the raw water pump serviced new bearings,shaft,seal and impellar and gasket, took the heat exchanger off and took apart and cleaned, strobe to timming shows 10degrees after TDC so I know I will have to ajust Distributor, but if timming out will this make it overheat, any advice much appreciated.
T1ony

 

[mftopgun]

check your exhaust manifold for water flow

 

[joe_merchant]

The hose connection and it's gasket on the top of the intermediate section are known sources of leaks. As you get up on plane, the connection is out of the water and will start sucking air. A visual inspection may not show any wear since it corrodes from the inside.

Here's a link to a similar problem and the possible solutions: http://www.marineengine.com/boat-forum/showthread.php?382536-volvo-penta-1986-AQ131-air-in-uptake-tube&highlight=overheating

One of the links inside that post also has a photo with instructions on how to replace the fitting without removing the upper gearbox.