181 Marine Power FLJ

[clearwater jet]

I inherited this 1977 Glasply 16' jet boat with the 181 4 cylinder motor. Does anyone no where I can get a manual on the engine, as well as parts?

It has been sitting for several years so I changed oil/filter & did a full tune up.

I dunked it yesterday & it started well, but no water pumped through the engine which quickly overheated. I blew air unobstructed through all the ports & exhaust vent. Would that be a shot circulating water pump?

Any info would be appreciated.

[Jango]

What you have, I believe, is similar to the 3.0 Mercruiser (Chevrolet) Engine, except configured to drive an impeller. Most auto parts stores have repair manuals. CLYMER is one I have seen.
And yes, it sounds like your cooling problem is most likely a water Pump impeller. They are made of rubber and typically last only a few years. Also, Make sure your water pump Inlet is not restricted.

[clearwater jet]

Hey thanks! Do you know a good parts supplier for it?

[rasorinc]

I believe this is your engine. It is a 3.0 marine block built by GM and marketed
by many others with their name on it. Volvo, Merc, OMC, etc. But it is a GM block--all of them.
http://www.michiganmotorz.com/Marine...pplications%29
Any large auto parts stores should be able to find parts for this engine. Tell them you want the MARINE PARTS.
GM still makes them--see here--http://www.gm.com/experience/technology/gmpowertrain/engines/specialized/marine/marine_engines.jsp
If this does not open just google GM Marine engines for the current stats on the 3.0

[clearwater jet]

This engine is still not pulling water in, and does not have a raw water pump, so I pulled the water circulating pump & it looks fine. We poured water in thru the upper large hose (thinking perhaps it had to be primed) & tried again w/ no luck. I can't find any air leaks; all drain plugs are closed. I'm replacing the thermostat just because it looks rusty.
The engine cooling water intake appears to be in the jet impeller housing. Do I have to have the jet impellers turning to force water in?
Any ideas?

[Jango]

Not familar with jets! But, if the cooling intake is in the Impeller Housing, Yes you probably need the impeller[s] turning. Sorry, I can't be of more Help. Not sure if Jets use a diverter to prevent thrust during low motor speed or simply rely on motor [pump] speed to create thrust.

[old hat]

clearwater,
you have a rare and awesome boat, dont give up yet. I have the same boat and thought it was the only one ever made. i fixed mine up from the dead and what a boat. i have some of the answers you are looking for.
the overheating, yes the jet pumps the water for cooling, it wont break- the port could be plugged , but unlikley . check the heat exchanger and sand trap for debries and clean- if equipped. are you testing in the lake water or running off a garden hose?

[gonzo]

Jet boats use a water bypass to feed water to the engine. If you run it on the hose, there should be a water connections somewhere and you can test if the water circulates. It is a GM engine still in production. All parts are available.

[clearwater jet]

Thanks for the good advice & encouragement guys. Turns out the jet impeller is not turning hence no water pumping into engine. Probably a key broken off. Will take apart asap and repair.