stranded on the water please help!!

[cruachan83]

My family is new to the boating world and don't have much experience. This is why we have had some problems. Our first winter we did not winterize the boat and because of this we cracked the exhaust headers. That was not the problem, though. The problem was that we ran the boat without knowing this and subsequently cracked the block and head gaskets. So we got the engine (mercruiser 4.3 carburated) rebuilt and we brought it out on the water. At first the boat would only go to about 3300 rpms at full throttle, barely enough to plane. then that got a little better we now climb up to about 4500 rpms at full throttle, but our real problem came when we shut off the engine to swim in the lake. When we got back on and tried to start up again the ignition would turn over but the engine wouldn't start. This has become an on going problem. We tried using starter fluid and everything. It usually always starts fom the cold start but after its warm and we shut it off, it will not restart. So my question is what would be causing the engine to perfom at fewer than normal rpms and why won't it restart after running for a while (30mins to a few hours)?

 

[njlarry]

Re: stranded on the water please help!!

The mechanics here will likely have a list of items to check but why not take it back to where you got the rebuild? Make sure it's not overheating. Also are you maybe flooding the engine, it doesn't need to be primed when warm. Whatever it is don't get discourged, it will likley be "simple" once the pros figure it out.

 

[Coors]

Re: stranded on the water please help!!

A carb'ed engine always needs a crack of the throttle to start it; unless you have an internally leaking q-jet.

 

[Wotknot]

Re: stranded on the water please help!!

My family is new to the boating world and don't have much experience. This is why we have had some problems. Our first winter we did not winterize the boat and because of this we cracked the exhaust headers. That was not the problem, though. The problem was that we ran the boat without knowing this and subsequently cracked the block and head gaskets. So we got the engine (mercruiser 4.3 carburated) rebuilt and we brought it out on the water. At first the boat would only go to about 3300 rpms at full throttle, barely enough to plane. then that got a little better we now climb up to about 4500 rpms at full throttle, but our real problem came when we shut off the engine to swim in the lake. When we got back on and tried to start up again the ignition would turn over but the engine wouldn't start. This has become an on going problem. We tried using starter fluid and everything. It usually always starts fom the cold start but after its warm and we shut it off, it will not restart. So my question is what would be causing the engine to perfom at fewer than normal rpms and why won't it restart after running for a while (30mins to a few hours)?

2 things come to mind, but as usual there could be other reasons..... #1, it's vapor locking after you shut it down.....take the cover off the engine and let it cool down and get some air inside the engine compartment.

#2, you've got a coil breaking down when it heats up.....thus after cooling down it starts.

Hope this helps.

 

[4winnsskipper]

Re: stranded on the water please help!!

My family is new to the boating world and don't have much experience. This is why we have had some problems. Our first winter we did not winterize the boat and because of this we cracked the exhaust headers. That was not the problem, though. The problem was that we ran the boat without knowing this and subsequently cracked the block and head gaskets. So we got the engine (mercruiser 4.3 carburated) rebuilt and we brought it out on the water. At first the boat would only go to about 3300 rpms at full throttle, barely enough to plane. then that got a little better we now climb up to about 4500 rpms at full throttle, but our real problem came when we shut off the engine to swim in the lake. When we got back on and tried to start up again the ignition would turn over but the engine wouldn't start. This has become an on going problem. We tried using starter fluid and everything. It usually always starts fom the cold start but after its warm and we shut it off, it will not restart. So my question is what would be causing the engine to perfom at fewer than normal rpms and why won't it restart after running for a while (30mins to a few hours)?

wait, just need to confirm you got a NEW block first, then had that rebuilt rather than having the cracked block rebuilt..........

 

[Coors]

Re: stranded on the water please help!!

A voltmeter to check voltage; changing the filters, checking the fuel delivery. I will get jumped by Don, but search, in here: how to test fuel problem. how to test start problem, etc