Speakrdude
Ensign
- Joined
- Feb 25, 2004
- Messages
- 942
Where do I start. (the timeline for all of below is 20 hours on engine)
Engine info: 1990 Merc 5.7L, had cracked everything when I bought. Shop repalced heads, block, long block (typical marine)rebuild. I install Seakamp (half cooled) cooling system.
In the beginning, I had a fresh new rebuild, new mans, water pump, fuel pump, everything. Then, we noticed the dribbling fuel from the venturies, causing a hard warm start. (seemed to be flooded)
But ran OK. Rebuild carb twice, every trick in the book. Same thing, but seems to idle good and be pretty crisp.
Was at that time, I checked a vaccuum gauge, a little at 12~15 in, but farily aggressive RV could cause this, so I'm told.
A couple of engine hours later, I noticed there is quite a bite of tapping noise coming from the rockers. Removed covers, sure enough, there were several loose rocker arms. (Did the reman shop not do a thorough job?) Shop said the rocker studs are pressed in and could be coming loose or nuts are going bad?
Took all back to -0- lash and tightened half a turn (by-the-book)
Sounds great now! (Runs OK)
LAst week, Sold boat. Delivered to the customer. While I was out of no wake area of the marina and by myself, took her up on plane, 4400RPMS, Denotation! Engine dies.
Tried to start, only running down #1 battery. Opened hatch, looked down carb throat, getting gas, good. Must have been trash in the tank and now in the fuel filter. Switched over to #2 battery, holding throttle wide open because by now, is flooded. Starts up! Idle back to dock. Tell customer about the stall and change fuel filter/seperator and check things over for his next outting.
Hear from the customers first outting, (he just fast idles around the lake a little) that all is well, still kind of hard to start when warm and idle seems a little low. (dies when manuevering foward to reverse into slip)
No problem, I run up to slip the next couple of days, increase nuetral RPMS to 850, in gear solid 650) check timing, all good. Engine sounds great, life is good. However, I did notice the coolant expansion tank is almost full and a little bit of spill over in the bilge! (full cold should be about 25% full)
I checked the heat excahnger and it is low. I poured some of the coolant back into tank, really puzzled.
Customer now ready for his Saturday out on the water with the kids.
Saturday afternoon rolls around, and you guessed it, customer calls and is stranded down lake, engine wont catch. It almost does but wont quite. I instruck (again) the flooded starting proceedure. Still no go.
Off to the rescue I go.
I reach the clients boat at almost sunset and sure enough, wont quite start. Almost but not quite. I notice the expansion tank is full again with a little spillage. Hmmm.
Also, when I crank over the boat to try start, I am seeing, what looks like steam, coming out of the port side rocker cover vent tube on every strock of of the engine!
I toe them back in.
My next course of action is a compression test, Tuesday. That is where the beginning of the trouble shooting process begins.
I am guessing, I have a hole in a piston (or worse), causing the blowby and no start condition, but wont know till I begin the investigation. Lots of possibilities I suppose.
Any thoughts?
Engine info: 1990 Merc 5.7L, had cracked everything when I bought. Shop repalced heads, block, long block (typical marine)rebuild. I install Seakamp (half cooled) cooling system.
In the beginning, I had a fresh new rebuild, new mans, water pump, fuel pump, everything. Then, we noticed the dribbling fuel from the venturies, causing a hard warm start. (seemed to be flooded)
But ran OK. Rebuild carb twice, every trick in the book. Same thing, but seems to idle good and be pretty crisp.
Was at that time, I checked a vaccuum gauge, a little at 12~15 in, but farily aggressive RV could cause this, so I'm told.
A couple of engine hours later, I noticed there is quite a bite of tapping noise coming from the rockers. Removed covers, sure enough, there were several loose rocker arms. (Did the reman shop not do a thorough job?) Shop said the rocker studs are pressed in and could be coming loose or nuts are going bad?
Took all back to -0- lash and tightened half a turn (by-the-book)
Sounds great now! (Runs OK)
LAst week, Sold boat. Delivered to the customer. While I was out of no wake area of the marina and by myself, took her up on plane, 4400RPMS, Denotation! Engine dies.
Tried to start, only running down #1 battery. Opened hatch, looked down carb throat, getting gas, good. Must have been trash in the tank and now in the fuel filter. Switched over to #2 battery, holding throttle wide open because by now, is flooded. Starts up! Idle back to dock. Tell customer about the stall and change fuel filter/seperator and check things over for his next outting.
Hear from the customers first outting, (he just fast idles around the lake a little) that all is well, still kind of hard to start when warm and idle seems a little low. (dies when manuevering foward to reverse into slip)
No problem, I run up to slip the next couple of days, increase nuetral RPMS to 850, in gear solid 650) check timing, all good. Engine sounds great, life is good. However, I did notice the coolant expansion tank is almost full and a little bit of spill over in the bilge! (full cold should be about 25% full)
I checked the heat excahnger and it is low. I poured some of the coolant back into tank, really puzzled.
Customer now ready for his Saturday out on the water with the kids.
Saturday afternoon rolls around, and you guessed it, customer calls and is stranded down lake, engine wont catch. It almost does but wont quite. I instruck (again) the flooded starting proceedure. Still no go.
Off to the rescue I go.
I reach the clients boat at almost sunset and sure enough, wont quite start. Almost but not quite. I notice the expansion tank is full again with a little spillage. Hmmm.
Also, when I crank over the boat to try start, I am seeing, what looks like steam, coming out of the port side rocker cover vent tube on every strock of of the engine!
I toe them back in.
My next course of action is a compression test, Tuesday. That is where the beginning of the trouble shooting process begins.
I am guessing, I have a hole in a piston (or worse), causing the blowby and no start condition, but wont know till I begin the investigation. Lots of possibilities I suppose.
Any thoughts?
