Greetings everyone,

Another frustrated rookie in need of help. In March of this year I bought a 1985 Skiff Craft X260 with twin AQ145B and 290 SP outdrives. I knew there were some problems i.e. rough running starboard side engine that also overheated, and both outdrives needed the tilt cylinders replaced. I've been working on these things myself since my Marine Mechanic went AWOL, and has been missing in action since March. I'm mechanical, but not a mechanic. I replaced both tilt / trim kits (fyi, not a job for a rookie) and also water pump impellers on both engines. I guess these are partially closed cooling systems, but still also draw outside water. So today was the moment of truth for test starting. I used a trough instead of muffs to create a more true idle running environment. The good - Portside started... ran perfect at idle, and engine temp kept at a nice medium range. Both outdrive trim tilt operate perfectly. The Bad - Starboard engine runs rough, and got uncomfortably hot within 2 minutes. I took videos of how much water is exiting at the exhaust port (wondering if someone can tell me if it looks normal), and I also noticed and videoed that real hot engine rubber smoke you get when the block is overheated (fyi, I did shut it down before gauge went red). The heat fumes were coming mainly from the area where the rubber exhaust boot that connects exhaust manifold to the exhaust tube. Also the exhaust water was almost steam right before I shout it down. Any help anyone can offer would be greatly appreciated as my kids are hoping for a fun 4th of July on the Water. added note - Both engines were rebuilt in 2003. Can't post videos till tomorrow.

Thanks in advance,
Greg

 

I was able get a hold of Master Marine Mechanic who stated if the impeller was not replaced with OEM Volvo Penta impeller, then that was more than likely the issue. He stated next he would try checking the thermostat. Just to be sure I went ahead and purchased and installed a Volvo Penta Impeller and we're still overheating. I let it cool down for about 20-25 minutes, drained the cooling system, pulled the thermostat out completely, put the housing back together, fired it up, and still overheating, although it took longer (about and extra minute or so) without the thermostat installed. So now what? The 4th is coming and some kiddies are going be let down. I've also read on other blogs it could be restricted water flow at the exhaust manifold into the exhaust tube. How do I check that out? Any tricks to be aware of pulling the exhaust manifold? Also, If I pull the manifold, is it directly connected to the closed cooling loop, or does that just flow through the block, and not interconnected? If I get it all apart and find that it has corrosion build up, can I just pressure wash it out of those areas? Questions, questions, questions!

Thanks again to anyone,
Greg

 

So the issue ended up being the connecting hose and water outlet (had disintegrated) that connects the uptake tube in the outdrive to the raw water pump. To figure this out on a hunch, I connected a bypass hose directly from my water tank/trough to the raw water inlet pipe/tube leading to the water pump. That gave me full circulation through the pump, engine block, and out through the exhaust keeping the temp in range. That told me the issue was before the pump, so I back flushed with a water hose through the out drive and discovered water leaking at the water outlet connecting hose junction. If it leaks water it also leaks air, so that was the issue.
Thank you God for the epiphany to track that down!
Also, if you are ever looking for older OEM Volvo Penta Parts, may I suggest US Boatworks- https://www.boatengine.com/shop-part...o-penta-parts/ They had everything I needed for my 1985 Skiff Craft with Twin Volvo AQ145B engines & 290 outdrives.

Carry On everyone!
Greg

 

Nice post, with a useful link. I've had a 70's Chivers Marine boat (ex Western Australia police), which came with an AQ130 with a 100 leg. Over the years I have upgraded to an AQ131 with 280 drive. It's great to have a forum where we can try to help each other to keep these things running as information and parts is becoming more difficult to get hold of.
Cheers Alex