Starter makes hard clunking noise

[Johnny Smith]

I have bought a Marada MX2 Sport Series boat. I smelled fuel in the bilge area and quickly addressed a leak from the sending unit. While closer inspecting the fuel system I noticed a non marine carb. I bought a new Holley 4 barrel from Holley. The boat initiall started after a little coaxing and ran great. It was just a test run. I turned it off at the dock. It wouldn't start when I tried to get it to the trailer. I tried starting it for a bit working the throttle until I noticed a little drag from the starter/battery. I took the boat home removed the battery and checked the charge with a load test. It was fine. I took it back to the water the next day and all I get is a hard clunk from the starter. I tried 5 or 6 times to no avail. Pulled it out of the water again and removed the starter. It tested good. I haven't pulled the plugs, but is it possible the cylinders are full of fuel? If so did I hurt anything from trying to start it? Thanks for the help. This forum is fabulous...

 

[Don S]

Re: Starter makes hard clunking noise

Sounds more like water in a cylinder than fuel.
Pull the plugs and turn the engine over by hand

 

[bigskiohio]

Re: Starter makes hard clunking noise

a hard clunk usually = water in cylinders.

 

[Johnny Smith]

Re: Starter makes hard clunking noise

I pulled the plugs and they were saturated with fuel. I turned the engine over and it burped what seemed to be fuel out of the two rear cylinders mostly. The oil level was very high and also smelled like gas. The oil was just changed so it was very clean anyway, but it had no milky residue. The engine turned smoothly and had 120 pounds of compression on each cylinder. I bought a 600 cfm 4 barrel that was tuned by Holley for these motors. I have no idea how to adjust these carbs, but doesn't it seem ridiculous to have that much fuel dump in to the motor? I tried starting it after the test run by working the throttle some, but I didn't think it would have been long enough to dump that much fuel. I guess the good thing is the motor seems ok. Any advice on what to do with this carb? Thanks for the help!

 

[Johnny Smith]

Re: Starter makes hard clunking noise

BTW It is a 4.3 Volvo Penta I/O. Thanks

 

[EddiePetty]

Re: Starter makes hard clunking noise

......I pulled the plugs and they were saturated with fuel.

I turned the engine over and it burped what seemed to be fuel out of the two rear cylinders mostly.

The oil level was very high and also smelled like gas.

.... but doesn't it seem ridiculous to have that much fuel dump in to the motor?

...y'all gonna think I sound like a broken record, but, here goes for yet another post.

All that fuel down the throat of the carb sounds like a fuel pump puking gas through the fuel pump vent, though it could possibly be a ruptured power valve in the carb.

Either way, with the oil level so high, the oil and filter must be changed no matter how new the oil is.

 

[jerryb1]

Re: Starter makes hard clunking noise

BE VERY CAREFULL CRANKING THE ENGINE WITH EXCESS FUEL AROUND!!! A friend recently buned up his boat and almost was killed from the explosion. With the plugs out he took off the coil wire thinking that would be good enough, but apparently it wasn't. Make sure you ground the primary side, so no high voltage is created anywhere!

 

[Don S]

Re: Starter makes hard clunking noise

Does your engine have a mechanical or electric fuel pump, and what year is your Volvo Penta. It makes a big difference.

If it's a mechanical fuel pump, a bad pump can and will fill the crankcase with fuel, but no way can it fill the cylinders full of gas as the engine has to be running for the pump to pump anything. Hardly enough to fill a cylinder when you shut it off, the pressure would bleed off in a hurry with it leaking into the crankcase and the carb.
NOW, if you have an aftermarket fuel pump that runs anytime the ign. switch is turned on, and the the float in the carb sticks open, yea, you would fill up a cylinder, but only leakage by the pistons would get fuel into the crankcase, and you have gallons.
You don't have both types of fuel pumps do you? I have had two boats with two working pumps come into the shop this year. I couldn't believe what some people will and can do to ruin a boat in the name of fixing it.

 

[Johnny Smith]

Re: Starter makes hard clunking noise

It does have a mechanical fuel pump. It is a 1997 model engine. Sorry I didn't give that detail earlier. When I initially brought the boat back in from the test run (after running great) I turned it over several times. It sat for 48 hours while I read up on adjusting the carb. The only thing I did in the mean time was take the battery out to make sure it was charged and load tested. I literally did nothing else. I carried it back to the lake to try my carb adjustments, and that is when I got the dreaded clunk from the engine. It was turning over when I pulled it out of the water after the test, then sat for two days, then clunk. I have always been careful to never start it with fuel fumes present, and I appreciate that advice. I am changing the oil today, and I am going to have an experienced mechanic look at the carb as I never had this problem before the carb was changed. I will keep you posted.

 

[Johnny Smith]

Re: Starter makes hard clunking noise

In the previous post I stated mechanical fuel pump, but it is electric. Don't know why I said that. Upon having an experienced Tech look at the boat he noticed milky residue under the oil filler cap. The dip stick looked like thin clear oil making me believe fuel diluted because of the carb replacement. We were sucking the oil out and it had a grayish tint. I was totally off on thinking it had fuel locked. Sorry for the ignorance. It appears that it was mostly water. I guess I was seeing water come out of the cylinders and assuming it was fuel. I am obviously not a mechanic. We ran the boat for a while with muffs and the carb performed fine with the exception of a little stumbling on idle. The number 3 cylinder seemed to be the culprit. I compression checked the system the day before with 120 psi on each, and the boat always runs cool and performed well until this carb change. About 2 months ago the impeller went out and the motor ran hot for a very little bit, but it was HOT! I had the impeller, flappers, and oil changed then. I have ran about 2 tanks of gas out of the boat. (30 gallons each fill up) The fuel leak happenned, I changed the carb, and then the locking of the motor was next. After turning the motor over without plugs freeing the cylinders it ran great in the driveway. The Tech is suggesting a bad head gasket. I totally know water is in the oil, but a head gasket seems would cause low compression, over heating, or something performance related; however the #3 cylinder seemed to be effecting the idle. (wire maybe) I guess it was just a coincidence the carb was replaced just before my problem. I guess I assumed it was connected, but the carb did fine idling in the driveway for 20 minutes. Is the best option to remove the head on the #3 side and check the gasket or should I do something else?
Thanks again.

 

[Bondo]

Re: Starter makes hard clunking noise

About 2 months ago the impeller went out and the motor ran hot for a very little bit, but it was HOT!

Ayuh,.. I'd pull both heads,+ have 'em tested at a Machine Shop,...
Sounds like 1 or both are cracked from the overheat...