I've got a 1988 bayliner w/ a chevy 305. Its been a strong runner, seems to be pretty well maintained (oil changes, spark plugs, new distributor,) and has run strong all summer. Yesterday on harris we were cruising back to the ramp at abouto 45 mph (full throttle) and lost power pretty suddenly and it dropped down to about 30 mph, RPMS came down too.

Idled it down, and the engine started running roughly (almost shaking, like its got a miss), white smoke came out of the valve cover breathers and some out of the carb. It also makes a pff pff pff pff sound now.

I haven't had time to take a good look at it, but did verify all spark plug wires were still attached. I think its an internal problem, possibly a cracked / dropped valve or head gasket.

I'm going home to get my compression tester tonight and narrow it down.

Any ideas?

9/28/2006 7:13:11 PM

off hand, sounds like a head/head gasket. def. do a a compression/leakdown on it and report back.

9/28/2006 7:35:28 PM

i'm gonna go ahead and call the port front intake gasket leaked coolant into your #2 intake and you now have a busted piston or bent rod, and if you shut it off like that and start it back up, #4 and 6 will be next to go, it's a mercruiser achilles heel, just finished another one up a few weeks ago in a 96 hurricane, plan on a full rebuild, punch it out .030 over, get a speedpro rebuild kit from summit with forged pistons and you can get out of it with a good motor for less han $700, its also a good time to replace all your hoses, thermostat, timing chain, and if it has a flat tappet cam, a 262 duration cam kit from comp cams for >$150 to really put some ass behind it, if its a roller cam, check it and stick it back in

[Edited on September 28, 2006 at 10:26 PM. Reason : i have a 2 ton 96" hoist that works great for that, that you can borrow to pull it if you need it]

9/28/2006 10:23:46 PM

Well, its an OMC, not a merc. but the engines probably are basically identical. If its that bad, it'll get a 350 w/ marine head gaskets and all the accesories from the current engine.

9/28/2006 11:49:51 PM

I miss my bayliner

9/28/2006 11:55:19 PM

I didn't even think about the hoist you'd have to have, my buddy has an A-frame that I'll think will work, thanks though!

9/28/2006 11:58:13 PM

^^^are you sure it's omc? as far as i know, all bayliner i/o's were/are badged as mercruisers. i know omc crossed some lines with their stern drives into some non omc hulls, but i'm not aware that bayliners were one of them. IF it is omc, it would have the cobra setup in that year. is that badged anywhere?

that aside, the problem you have is likely limited to the engine itself which would be generic despite the rebadging and external differences. the main differences in the omc vs. mercruiser stern drives in the mounting/trim systems.

i could definitely be wrong with all that... my marine experience is relatively limited.

9/29/2006 4:17:08 AM

check the tag on the port side of the block on the side right at the drive coupling housing, should be a merc

9/29/2006 7:58:30 AM

good. one less pleasure boat on the lake.

9/29/2006 8:23:18 AM

yeah, damn pleasure

you're just lucky its getting too cold to ride the jet ski

[Edited on September 29, 2006 at 10:33 AM. Reason : .]

9/29/2006 10:32:53 AM

It is an OMC cobra, its got badges all over, I couldn't find any mercruiser badging.

9/29/2006 10:55:36 AM

i'll be damned, unless its a retrofit, i've never seen one in that year bayliner

9/29/2006 1:07:10 PM

found an engine donor, 1978 K5 blazer w/ a 1993 350 w/ 30K miles on it. It must have been injected originally b/c the fuel pump boss is cast over. Shouldn't be a problem using an electric fuel pump to the quadrajet on the boat. Probably going to bolt on a set of junkyard 062 vortec heads and put SS headgaskets on it before it goes back in the boat. Should be good for 260-275 hp and a good bit more torque than the 305 (235 hp).

I only wanted the engine, but had to take the whole truck, but the price was right. (truck had no axles or driveshafts, dcwalton and I had to put axles under it to get it on a trailer)

10/1/2006 1:44:50 PM

^that the one richard was selling?

10/1/2006 2:58:46 PM

no, I got it from a friend of mine in johnston county

10/1/2006 5:48:07 PM

ah. guy i know on nc4x4 is selling one that sounds pretty much identical. i think it was newer though...

10/1/2006 6:48:49 PM

just make sure to get a uscg approved marine pump, bilge explosions arent cool

10/1/2006 10:12:37 PM

We got the engine pulled out of the blazer and pretty much have it ready to go in....but after removing all the accessories from the engine in the boat, i cannot tell if i need to remove the outdrive before the motor, or if i can just slide the motor forward some when pulling it..Anyone know the answer?

10/13/2006 11:08:36 AM

you have to pull the outdrive with the shaft out of the drive coupling before pulling the engine

10/13/2006 10:36:01 PM

found the prob in the old engine



[Edited on October 16, 2006 at 5:28 PM. Reason : .]

10/16/2006 5:28:00 PM

thats nothing, you shoulda seen the one i pulled down last month

10/16/2006 5:29:10 PM

^ i helped pull that bitch too and yes it was one fucked up piston

10/16/2006 6:41:23 PM

Is that from detonation?

10/16/2006 9:03:06 PM

Thats my theory, anyone else have any guesses?

10/16/2006 9:39:59 PM

the flecks of carbon missing off the piston head indicate water flashing to steam in the cylinder to me

10/17/2006 7:36:50 AM

actually that isn't missing carbon, but pieces of the aluminum piston that melted back onto the piston coming from the hole.

10/17/2006 9:28:45 AM