merc 650 carb/idle problem

[mbrownone]

1967 Mercury 650 Outboard
The Good:
- Just cleaned both carbs (although floats were in great condition so I didn't replace)
- replaced all gaskets in carb
- engine starts and runs smoother at higher rpms
- all controls appear functional I think

The not so much good:
- have not taken to the lake yet for trial and have used only muffs to test engine so far
- carb appears to still leak fuel from top of bowl after priming the tank bulb and making firm
- engine stalls when right warm up lever on the controls approaches completely down. About 2 inches left then stalls

The questions:
1. Would the float or inlet needle (or both) be the cause of the leak under primer pressure?
2. What reasons would cause the engine stall when lowering the warm up lever to the down position?? Engagement of forward gear is not possible until lever is down.
3. The lower of the 2 carbs appears great and free of any leaks. Is this because fuel enters the top carb first?
4. Can the choke selinoid be a part of the problem? How would I test that?
4. What should I be looking at now?

Comments and instruction from your experiences and skills are very much appreciated. Thanks to all!

 

[merc850]

Re: merc 650 carb/idle problem

1: Yes the float setting might be off or it could be fuel logged and sinking.
2: The idle might be set too low with the idle stop screw or the low speed needles might not be set to 1 1/2 turns out. You have to set the idle - in gear - running in lake, not on muffs.
3: Remove the brass plug on front of Nr.3 carb and see if you can pump fuel out of it.
4: The choke solenoid is a go/no go item, with the cowling off hit the choke button on the control and watch for the choke shutters to close. The choke is a press the button until it starts type.

 

[mbrownone]

Re: merc 650 carb/idle problem

Sorry for the late reply. Had a storm here which actually uprooted a 150 year old oak tree (quite a sight).

Thank you for the response. I corrected the leak in the float bowl by tightening the float bowl screw. Was afraid of torquing too much at first, but apparantly wasn't tightened enough.

Will have the boat on the water soon and set the idle while in gear as you suggested. Engine starts and runs well so far, but will need to work on the stalling issue when at low idle. Maybe setting the idle a little higher will do the trick.

Thanks again. Will let you know.

 

[mbrownone]

Re: merc 650 carb/idle problem

My engine only has 2 carbs (its the 4 cylinder)

The idle stop screw is ok, but where are the low speed needles and how do you set them at 1.5 turns??

Thank you again for the help