inboard merc 454 dies when put into gear

[tfitz717]

Working on 1984 Mercury 545 340 hp engine in 1984 chris. When i put the engine into gear, the trans clacks then the engine dies. I have checked timing and electrical systems with no help. Swapped carbs with good port engine and problem went with carb. I had the carb rebuilt and problem remains. Both engines are running with no thermostats and old bi metal chocks. Any ideas would be helpful. Thanks Terry

 

[alldodge]

Re: inboard merc 454 dies when put into gear

Working on 1984 Mercury 545 340 hp engine in 1984 chris. When i put the engine into gear, the trans clacks then the engine dies. I have checked timing and electrical systems with no help. Swapped carbs with good port engine and problem went with carb. I had the carb rebuilt and problem remains. Both engines are running with no thermostats and old bi metal chocks. Any ideas would be helpful. Thanks Terry

Does it die abruptly with no turn of the trans at all, if so do you think the trans is frozen?
What happens if you increase the idle a bit, does it still die?
Have you checked the trans fluid?
Have you checked compression?

 

[CharlieB]

Re: inboard merc 454 dies when put into gear

Check the lower shift cable, if it is dragging it is holding the shift interrupter switch too long, killing the motor.

It may be time to replace that lower cable.

 

[thumpar]

Re: inboard merc 454 dies when put into gear

Check the lower shift cable, if it is dragging it is holding the shift interrupter switch too long, killing the motor.

It may be time to replace that lower cable.

It is an inboard.

 

[CharlieB]

Re: inboard merc 454 dies when put into gear

......................... When i put the engine into gear, the trans clacks then the engine dies. I have checked timing and electrical systems with no help. Swapped carbs with good port engine and problem went with carb. I had the carb rebuilt and problem remains..

I missed this part the first time around.

The carb is still dirty in the idle circuit. Once load is applied the motor demands more fuel, can't get it, and dies.

If your model carb has a power circuit/valve then it could be sticking and not responding to the drop in intake vacuum.

Either way, the answer is still inside that carb.

Sometimes mineral accumulation is so solid, even the best of chemicals have difficulty removing it, careful probing with very fine gauge wire may be needed to restore full flow thru a jet, fuel and or air passage.

I like to spray a good chemical thru everywhere so I can see that it is flowing thru each passage, follow that with high pressure air to remove all traces of gunk and my solvent. WEAR GOGGLES.

 

[thumpar]

Re: inboard merc 454 dies when put into gear

If the problem followed the carb then you have your answer like CharlieB stated.

 

[littlebookworm]

Re: inboard merc 454 dies when put into gear

Since the problem followed the carb, the problem is most likely the carb itself. The passages in a carb are extremely small; clearing them with a wire can sometimes cause more problems than it cures. Years ago, when I was an auto mechanic, we would take the 'high road' when it came to a problem carb - replace it. You could spend hours and hours cleaning and rebuilding your carb and still have problems, something you don't need on the water. My suggestion is to get a new carb and eliminate your problem. Hy