Leaking crank seal
 

Hey guys, I'm looking for some advice and info. Let me first say that I am new to power boating. I recently bought an 01 29 fever with the 500hp efi. The motor had been rebuilt recently, with all new gaskets, pistons and such, with about 40 hours of use on the new motor. This spring, I put about 3-5 hours of use on the boat, then changed the oil, filter, and fuel filter. Let me add that the previous owner was using straight 40 weight valvolene oil, and when I did the oil change, I switched to 25-50 mobile1. After the oil change, I put another 3-5 flawless hours on the boat. This past weekend, I put another 3 hours on the motor, with maybe 3 or 4 short wot bursts, but no more than a mile or 2 at one time. Then on Sunday, I checked the oil of course before I was going to use the boat. When I opened the engine hatch, I could immediatley see oil in the bilge. I checked the dip stick, and I was around a quart low. I filled the oil to full, and put the boat in the water so I could try and trouble shoot the leak. The oil looks to be coming out of the crank shaft, accumulating on the water hoses and then running down to the cooler that is below the crank shaft. While troubleshooting, I only ran the boat at cruise speeds, and checked the leak very often. It only seems to be leaking while the engine is running, and the oil up to an operating temperature of 200. And even then it's just a drip from the hoses. Nothing appears to be spraying. So at this point, I would have to say the crank shaft seal is bad? But this concerns me with this motor only having around 50 hours of use on it. Could there possibly be a big problem causing this, or just a coincidence a seal has gone bad, and just have it changed? Also, how intensive is this job, I'm sure the gaskets are peanuts, just curious on time and what exactly needs to be done. Thanks for the advise guys.

Front main seal put oil in it till the season is over!!:whistle:

Timing cover seal? Front crank pulley wet with oil inside and bottom side of water criculating pump damp from a oil mist?

Remove the balancer bolt/washer, squirt some RTV in the keyway slot, reinstall the bolt/washer. Common problem

what us1 said, mine was doing the same thing, I pulled the bolt out and it was damp but kept going and did the crank/timing cover seal, the seal looked great:angry-smiley-038:, but I had one and did it anyway. All said and done it took prolly 2 hours.

I'd try just siliconing the end first.

Thanks for the advice guys. The plan of attack tonight is going to be to check the intake manifold first, to at least eliminate that as the culperate. The next step is to then take the balancer off, check for some rtc silicone that could possibly be installed already. If it is, then it must be the seal, if not then I'll try the silicone trick. Also , my father has a regular automotive balance remover, but due to limited space will that work, or is their one made for marine applications I will need?

oil leak
 

remember you MUST remove the water pump pully before removing the harmonic balancer . don't make that mistake . it will cost you .

If you go as far as pulling the balancer and replacing the seal, you will want to look at the balancer where the seal rides to see if its worn or grooved. it could have been overlooked by the builder. a 'sleeve' is available to press on the balancer to give the seal a new surface to ride on.

I had this problem with 2 motors last year. one i caught leaking while on the stand, one started leaking once it was in the boat and was changed while in the boat.

Feel the inside of the belt pulley and the bottom of the waterpump before you go taking things off. If those are wet with oil, just squirt some RTV in keyway and be done with it. No need to remove anything other than the bolt/washer if so.

Ok, that's for the heads up on the water pump pulley. Also, one of the mechanics I spoke with warned me about the possible groove on the balancer, but thanks for the heads up also. Just trying to at least prove what "is not" the problem, and if I don't think I can handle it after that, I'll hand it over to a marine mechanic. Us1, thanks for the heads up on not tearing too much apart. I think at this point I may have to run the boat in the water to try and get the oil to seep again to show where it is actually coming from. Last night I spent 3 hours cleaning oil and residue off of everything in the from of the motor since that was our plan of attack to try and eliminate what "is not" the problem to begin with. I'm going to get at it after work this afternoon so I'll report back on my findings. Thanks again guys

Everything on front will get a light oil film if the oil is leaking past the keyway. Oil leaks out the keyway, into the balancer/pulley, then gets flung off as the motor is ran. After enough oil has built up on the accessories, it'll run down and drip off the low point on each. You may also see a fling line along the hull sides and bottom. Just run your hand along the bottom of everything on the front of the motor.

If it's just an intake leak, oil will just run down the block, then drip onto the bottom. No flinging around.

Good Luck