1993 Chris Craft 238 Concept falling on its face under load

[TinMan77]

Good morning all. New to the board.

I have two problems I need help with.

First: when on the lake and I give the boat throttle, it occasionally seems to fall on its face as if it is starving for fuel. If I put it wide open it would increase speed and then fall flat and then pick back up again and fall flat. It was repetitive. On occasion it would run wide open as if it had no problem at all. On other occasions it would be cruising along and then just quit. It also would stumble and shut off when kicking it into gear at times as well.

Second: My temp gauge starts to run hot while cruising at higher rpms. When I bring it back down to about 1800 it would cool itself off. Go back to 3500 and it runs hot again. I pulled the impeller and it looks good.

1993 Chris Craft 238 Concept
5.8L OMC Cobra MPFI

any help would be greatly appreciated

by the way, I just purchased this boat about a month ago. I was told the engine was rebuilt 125 hours ago. I do not have any service history on it.

Thank you, Dale

 

[Scott Danforth]

With any new to you boat, you have to do all the maintenance.

Replace the raw water pump (easy to do on a cobra)

Replace bellows

As for performance issues, how old is the fuel?

 

[TinMan77]

What are the bellows?

also, the fuel was topped off at the end of the summer and had stabilizer put in it during winterizing.

 

[at dorris]

The bellows are those big black tubes that are connected from the back of the drive to the transom. The purpose of the top one is to prevent water from entering the boat and also to protect your u joints and gimbal bearing from water. The bottom one is to carry the exhaust to the prop through the outdrive. The top bellow should not have any cracks/slits in it, if it does replace it. The bottom bellow is supposed to have the bottom of it cut off so don't worry about it if it has holes in it.

 

[Scott Danforth]

What are the bellows?

also, the fuel was topped off at the end of the summer and had stabilizer put in it during winterizing.

fuel doesnt last that long, even with stabilizer

 

[TinMan77]

I notice, when hooked to the hose, warm/hot water is coming out of the lower unit close to the transom as well as out of the little vents near the prop. Is that normal?

As far as fuel goes... yesterday it ran for 20 solid minutes without a hiccup. Then all of a sudden if fell off and stumbled and shut down on me. When I went to restart it, it smelled like it was flooded. I had to give it throttle to get it to start back up if I didn’t wait for a few minutes.

 

[Scott Danforth]

Water from the idle relief ports is normal

The goo in the tank let loose and is now in your motor. Check your fuel/water separator

 

[TinMan77]

Where would the separator be located? I see the filter below the low pressure pump but I don’t see separator.

 

[Bondo]

Where would the separator be located? I see the filter below the low pressure pump but I don’t see separator.

Ayuh,..... Welcome Aboard,........ They are 1 in the same filter,.....

 

[Bander]

I have the same boat: 1993 Chris Craft 238 Cuddy, 5.8L OMC King Cobra that had a similar issue. My issue was the fuel pick up tube. There's a screen in the bottom of it that was full of crud. Ran great at low rpm, but when getting up on plane it would cut out.
It's accessible thru the table holder in the floor. Very tight quarters for large hands.

 

[TinMan77]

Thank you to everyone so far. I took the boat to the shop. They had it a few weeks. The temperature issue turned out to be a temp gauge. However, it still runs about 200 while in the lake at full throttle. The shop seems to think that maybe someone put an automotive thermostat in it. I talked to the previous owner, who happens to be a friend, and he said he has had the boat for several years and never changed the thermostat and it had always ran about 165 or so.

Second, the fuel problem was thought to be corrected by changing the separater and the fuel pressure regulator. I took it out and it ran great for about 20 minutes or so. I came to a no wake zone and while idling through it just shut off the engine. The radio and gauges stayed on. It was almost as if someone shut off the power to the fuel pumps. I turned the key off and back on and It did not sound like the pumps came on. I tried to restart and it just turned over. I cycled the key a few times until I could definitely hear the pumps and it fired up. After cruising for about 5 minutes or so, it stumbled while at about 30 mph. I pulled the throttle back and let it idle and took off again. This happened one more time before I got back to the boat ramp. The shop told me they think I have a loose connection in the purple wire running from the ignition switch to the fuel pump and for me to run a jumper across the floor from the switch to the pumps and see if it still does it. Does anyone else have any suggestions prior to me trying this possible solution out?

Thanks, Dale

 

[kenny nunez]

Try removing the main harness plug, you will notice that the pins have a split, take a small thin screwdriver and slightly spread them to give them a tight fit. This may not be the problem but worth trying.

 

[Lynn A.]

My 93 chris craft has just the opposite as that guy said solid bellows big one the smaller one is manufactured with holes in it at the bottom. If its Carbureted get your carburetor rebuilt that's what I also there's a screen chamber of sorts to keep things from getting sucked into the impeller and pumped up into the engine that might need to be cleaned out as well in front of the impeller line id chech that first they suck up grass kelp millfoil etc. Sounds like thats the problem if the impeller is still in good shape. I replaced my impeller took the old one lubed it up with vasaline put it in a ziplock in a little Tupperware container and have it stashed on the boat with some tools for just such an occasion. Sometimes they will get dried out brittle and all the fins just shred. Some take it out every winter but ive found when i winterize it the antifreeze keeps it moist enough to stay pliable. Its always a good idea to have a spare prop and impeller to keep u out of trouble and off the rocks. Dont change the carb the holley you have is a marine carb and a good one just take it to a propper hot rod shop spend the extra money have it rebuilt by a pro. It cost me about 300 but he knew way more about it than i did.

 

[Lynn A.]

Good morning all. New to the board.

I have two problems I need help with.

First: when on the lake and I give the boat throttle, it occasionally seems to fall on its face as if it is starving for fuel. If I put it wide open it would increase speed and then fall flat and then pick back up again and fall flat. It was repetitive. On occasion it would run wide open as if it had no problem at all. On other occasions it would be cruising along and then just quit. It also would stumble and shut off when kicking it into gear at times as well.

Second: My temp gauge starts to run hot while cruising at higher rpms. When I bring it back down to about 1800 it would cool itself off. Go back to 3500 and it runs hot again. I pulled the impeller and it looks good.

1993 Chris Craft 238 Concept
5.8L OMC Cobra MPFI

any help would be greatly appreciated

by the way, I just purchased this boat about a month ago. I was told the engine was rebuilt 125 hours ago. I do not have any service history on it.

Thank you, Dale

I replied down below. Great boat btw. I love mine. Handels rough water good smooth where a fourwinds slams this boats cushy. 351 winsor can be turned into a 427 btw if you felt so inclined and it would have arond 400 hp. Otherwise the 351 loves to be beaten. Itll run forever. Good luck dale once you get the bugs worked out she will be a great boat. This kind of thin happens when a boat sits. Its almost better to run it all the time than not at all. Dry storage tho in my opinion is the best and as long as you dont let it freeze and crack your block or blow a head gasket itll last a very long time. I dont work for chris craft but i do love em, they make a very stable sturdy well thought out boat.
Good luck. Its all just nuts and bolts dont be intimidated.

 

[Lynn A.]

Yay! I got a trophy! What does that mean? Im glad to have it yho and id just like to say thank you to all the people that helped make this possible, my Grad dad from Bellingham Washington ran a garage and a farm and had a road named after him Aldruch road. And my dad, he was mechanic for 18 years bla bla thanks. Stay safe.