hydro locked 305 mercruiser.what caused this?

[milliganwv]

i bought a 21' marada 1995 model with 305 mercruiser alpha 1 outdrive had the boat running on the muffs ran fine several times other than an idleling problem, went to the lake dropped her in an on my way she ran fine up until i sat her down off plane when she idle down she stalled and hydro locked after inspection of the motor an transom the exhaust bello is torn in two, and the rubber is gone off the y pipe flappers could this be the problem.

 

[Joshua Nichols]

Re: hydro locked 305 mercruiser.what caused this?

and the rubber is gone off the y pipe flappers could this be the problem.

Well yeah...

 

[milliganwv]

Re: hydro locked 305 mercruiser.what caused this?

im just learning boat mechanics so i wasnt sure if that would cause a hydro lock or if i have bigger problems

 

[Joshua Nichols]

Re: hydro locked 305 mercruiser.what caused this?

Pretty sure if you was running good and you know you have bad flappers... Then came off of plane hard and hydrolocked.. You water logged the engine..

Install ya some new flappers

 

[milliganwv]

Re: hydro locked 305 mercruiser.what caused this?

i have dryed the engine out and ran it. all seemed ok i have new flappers on the way if this boat was ingesting water from say a head gasket or cracked block i would have had problems on the muffs no?

 

[HT32BSX115]

Re: hydro locked 305 mercruiser.what caused this?

i have dryed the engine out and ran it. all seemed ok i have new flappers on the way if this boat was ingesting water from say a head gasket or cracked block i would have had problems on the muffs no?

Exhaust shutters(lack of) can cause that problem. a leaking riser gasket, cracked exhaust manifold or risers are also frequently the cause of hydrolocking.

If you had a cracked head or block you would probably also have water in the oil.


Blown head gaskets are not all that common......



Regards,



Rick

 

[milliganwv]

Re: hydro locked 305 mercruiser.what caused this?

had water in both sides of the engine but more so on the port side. if it where a riser or manifold would it not do it on the muffs in the drive way. and when i check the oil the level was ok an the color fine . im thinkin i need to install the new exhaust bello and flappers and try again i just dont wont to miss something and completely destroy this engine. if i can run this engine threw this summer im thinkin 383 stroker for next summer if this vessel turns out to be ok. it also could use a carb cleaning to stop low rpm stalling?

 

[Joshua Nichols]

Re: hydro locked 305 mercruiser.what caused this?

im thinkin i need to install the new exhaust bello and flappers and try again it also could use a carb cleaning to stop low rpm stalling?

I would try that first... Good luck on the stroker build.. Lots have done it on here

 

[milliganwv]

Re: hydro locked 305 mercruiser.what caused this?

thanks for all the insight since im a little way away from the boating season her in wv i might as well go ahead an change those riser gaskets. an if all else fails i guess i be droppin in that stroker sooner than later thanks guys

 

[HT32BSX115]

Re: hydro locked 305 mercruiser.what caused this?

When you get the risers off (of course you'll have to repace the gaskets), you'll see right away if there's evidence of water from the rust trails.

ANY rust in the exhaust area of the manifold is an indication of water in there either from a leaky gasket, or a crack in the riser OR manifold, or possibility of reversion (less likely on a stock marine engine) Or splashback from lack of shutters which is possible but not all that likely either....

Lack of exhaust bellows is not really all that big a deal..... ( my previous OMC 460 operated for about 15 years with NO exhaust bellows) pulling skiers and wake-boarders etc.....

I had a severe hydrolock problem too. Both riser gaskets were leaking profusely. EVERY TIME I shut down (right before I pulled the engine) it would hydrolock so bad that I couldn't start the engine for several minutes. (it always did eventually start though)

 

[Bondo]

Re: hydro locked 305 mercruiser.what caused this?

thanks for all the insight since im a little way away from the boating season her in wv i might as well go ahead an change those riser gaskets. an if all else fails i guess i be droppin in that stroker sooner than later thanks guys

Ayuh,... I'm thinkin' the backwash is what did the hydro-lock....
It sounds like your low speed/ idle problem is the real root Issue...
You say it Stalled comin' off plane...

Fixin' the exhaust is a Good thing, but I think the idle problem is the Cause...