tigerhunter
Cadet
- Joined
- Oct 1, 2008
- Messages
- 8
Hey all,
I have a '69 merc 500 and am having problems with it. On rare, random occasions the motor will run great and move my boat between 30-35 mph. Most of the time however the motor pushes the boat about 5-10 mph.
When I got it:
-Would start up and idle fine
-goes into gear fine
-goes about half throttle fine
-after half throttle the motor would bog as it started to plane
-half throttle or higher motor would run pretty rough (misfiring?)
I have since then cleaned the carbs, got a new fuel bulb, rebuilt fuel pump, and brand new plugs.
Now, same as before except:
-runs smoother from half throttle to full throttle
-doesn't seem to try to go on plane but goes the same speed if not faster than before (~1-3 mph)
The motor has a warm-up lever. I do not have a tach but I can rev it up with the warmup lever and it sounds like I believe it should but at full throttle in gear it sounds like it is running maybe half of its potential. It sounds as though every other beat has a small misfire.
At WOT I try to pump the fuel bulb and nothing really happens, the bulb is stiff and the added fuel does not help at all, almost seems like it hurts a little but is hardly noticeable.
Did a compression test a little while ago, the #'s were a little low but they were consistent and from what I've read consistency is more important than the actual #.
I assume it is something electrical now since I have done most of the fuel related fixes. I did buy some fuel fitting sealing stuff I want to put on all of the fuel fittings just to make sure they are all right.
Besides 'what next?' I have two other questions:
With the motor off in the garage, when I squeeze the bulb, if I squeeze long and hard enough should fuel shoot into the carbs and possibly come out the front of the carbs if the motor is tilted up?
I rebuilt the fuel pump, the two check valves were facing opposite directions, is this correct?
Sorry for the long post but I have been reading on this forum for a while and trying different things along the way and wanted to be as specific as I could.
Thanks for any help/input you may have.
Trevor
I have a '69 merc 500 and am having problems with it. On rare, random occasions the motor will run great and move my boat between 30-35 mph. Most of the time however the motor pushes the boat about 5-10 mph.
When I got it:
-Would start up and idle fine
-goes into gear fine
-goes about half throttle fine
-after half throttle the motor would bog as it started to plane
-half throttle or higher motor would run pretty rough (misfiring?)
I have since then cleaned the carbs, got a new fuel bulb, rebuilt fuel pump, and brand new plugs.
Now, same as before except:
-runs smoother from half throttle to full throttle
-doesn't seem to try to go on plane but goes the same speed if not faster than before (~1-3 mph)
The motor has a warm-up lever. I do not have a tach but I can rev it up with the warmup lever and it sounds like I believe it should but at full throttle in gear it sounds like it is running maybe half of its potential. It sounds as though every other beat has a small misfire.
At WOT I try to pump the fuel bulb and nothing really happens, the bulb is stiff and the added fuel does not help at all, almost seems like it hurts a little but is hardly noticeable.
Did a compression test a little while ago, the #'s were a little low but they were consistent and from what I've read consistency is more important than the actual #.
I assume it is something electrical now since I have done most of the fuel related fixes. I did buy some fuel fitting sealing stuff I want to put on all of the fuel fittings just to make sure they are all right.
Besides 'what next?' I have two other questions:
With the motor off in the garage, when I squeeze the bulb, if I squeeze long and hard enough should fuel shoot into the carbs and possibly come out the front of the carbs if the motor is tilted up?
I rebuilt the fuel pump, the two check valves were facing opposite directions, is this correct?
Sorry for the long post but I have been reading on this forum for a while and trying different things along the way and wanted to be as specific as I could.
Thanks for any help/input you may have.
Trevor