2000 Volvo 7.4 GI Wet Sparkplug

[dan08]

I have a 2001 model 2850 Regal LSC with a 2000 7.4 GI Fuel injected 454 with 130 original hours. The boat ran very strong last summer with never a problem. The boat was winterized(block drained) and stored inside (year round) in a heated (55 degree min) warehouse in Georgia. I began the process of dewinterizing and changing fluids this spring. I decided to change the spark plugs and when I pulled out one of the plugs on the starboard side a little water ran out and the plug was rusty on the end. The other 7 plugs all had the same wear and did not look bad. The engine oil had no signs of water in it. The boat has the original engine and has had little use. It is raw water cooled. It had some use in salt water in the 1st 100hrs of use by the original owner and the boat shows no signs of corrision externally on engine/outdrive. The boat was in pristine condition when I bought it 1-1/2years ago. I am looking for some direction of where to start. Do I have a blown head gasket, cracked head, head thats not torqued properly. Intake manifold gasket issue???????? Please Advise Dan

 

[Don S]

Re: 2000 Volvo 7.4 GI Wet Sparkplug

Did you run the engine on muffs before you drained the block?

 

[dan08]

Re: 2000 Volvo 7.4 GI Wet Sparkplug

Did you run the engine on muffs before you drained the block?

No. It is used in fresh water. After the last time I used it last year in fresh water I winterized the engine and drained the block.

 

[Don S]

Re: 2000 Volvo 7.4 GI Wet Sparkplug

It's possible you got some water in there when you pulled the boat out of the water if the stern was deep enough. Could also be a failing gasket between the riser and the manifold.

 

[dan08]

Re: 2000 Volvo 7.4 GI Wet Sparkplug

It's possible you got some water in there when you pulled the boat out of the water if the stern was deep enough. Could also be a failing gasket between the riser and the manifold.

I don't understand the theory about the stern being deep in the water. I do trailer it every time and it was on a steep ramp the last time i pulled it out of the water. Please Explain.

 

[Don S]

Re: 2000 Volvo 7.4 GI Wet Sparkplug

And I almost said if you was on a steep ramp.
What happens, is when you start pulling out, the weight of the boat pushes the back a little deeper than normal into the water. As the water gets forced deeper up into the exhaust further, it's possible some sloshed into the manifold and would get into the cylinder with open valves. Have seen it happen on steep ramps before. To the point that when we pull a boat for someone, we always put the drive down and fired the engine for a couple of seconds just to make sure there wasn't any water. In salt water, you tend to be more careful.

 

[dan08]

Re: 2000 Volvo 7.4 GI Wet Sparkplug

And I almost said if you was on a steep ramp.
What happens, is when you start pulling out, the weight of the boat pushes the back a little deeper than normal into the water. As the water gets forced deeper up into the exhaust further, it's possible some sloshed into the manifold and would get into the cylinder with open valves. Have seen it happen on steep ramps before. To the point that when we pull a boat for someone, we always put the drive down and fired the engine for a couple of seconds just to make sure there wasn't any water. In salt water, you tend to be more careful.

Ok. The ramp I pulled it up is so steep I bottomed out my trailer at the top of the ramp. It was the 2nd cylinder from the stern on the starboard side. Would it be worth putting the boat in the water and bring it up to temperature( pending it is running smooth)and then shut it down and check the plug for moisture. Would it be wise to check the torque on the riser / manifold. Any other suggestions before I start taking apart the riser to the manifold.

 

[Don S]

Re: 2000 Volvo 7.4 GI Wet Sparkplug

Crank the engine over (Not running) to make sure all the water is out of that cylinder. clean and dry the plug and reinstall it. Then run it on muffs. No reason to put it in the water to run it.

 

[dan08]

Re: 2000 Volvo 7.4 GI Wet Sparkplug

Got it. I will try it. Thanks