1979 merc o/b fuel pump might be bad

[Kapt Bobby]

The Motor ran fine all day then on the way home it got hard to start and died when I would power it up . NOW WHAT?????

 

[jimmbo]

It could be a lot of things. First of all, what engine?

A compression check should be done. When you take take the spark plugs out, you can examine them.
Is the fuel tank vent screw open?
Does the Primer bulb get firm when it is squeezed?
Does the bulb collapse when the engine is running?
Is the fuel filter/screen plugged?
Does it have a healthy spark, meaning can it jump a 7/16" gap?
Is the fuel getting to the carb?
Is the carb clean, with no restricted/plugged circuits(passages)?

 

[Kapt Bobby]

It is a 1979 70 HP ,Bulb was Firm , Vent OPEN,Filter CLEAN. It was running like it Ran when the Arm was broken off of the old Rotor that used to me on it. Just like the Rotor was not Moving to the Back Position.

 

[Kapt Bobby]

Oh it will run wide open and forever using that little Idle lever.It just Boggs down or Dies when you try to move under Power.

 

[racerone]

Any pictures of this " rotor "----I would start with a compression test.-----When was the water pump serviced last ?

 

[Kapt Bobby]

New Trigger, New Stator and new Impeller .I will get Pics up soon.

 

[Kapt Bobby]

When I saig it Ran like the ARM broke off of the ROTOR , I meant to sat TRIGGER not Rotor.Sorry

 

[racerone]

Perhaps it is LEAN on low speed mixture.----Open the low speed mixture needles 1/8 turn at a time and test run again.-----Likely the bogging will go away , perhaps after the first try. !

 

[Kapt Bobby]

I HAVE some misspellings in post 7 I did not have my Glasses on.

 

[Kapt Bobby]

When I bypass the Fuel Connector it seems like when I pump the Fuel Bulb ,it seems like it will shoot more Gas out. I will try to run it but connecting the Fuel Line right to the Fuel Filter instead of using the Twist on Fuel Connector. I think I will Rebuild the Fuel Pump and Carbs. I cant find a Rebuild kit for the Carbs anywhere.Any Ideas????

 

[jimmbo]

Oh it will run wide open and forever using that little Idle lever.It just Boggs down or Dies when you try to move under Power.

You shouldn't be able to get full throttle using the fast idle lever, if you are revving it to 5000 in Neutral, keep doing that, and you won't have to worry about any issues

 

[Kapt Bobby]

The 79 Merc 70 HP O/B has 90 Pounds in all 3 Cyls like it did 2 years ago when I checked it.

 

[Kapt Bobby]

I cleaned the Carbs and re Set the Floats ,There were out of Sink with eachother . I set the Float to be Paralel with the Carb base .I could not find any info on how to set those Floats for those Carbs. I rebuilt or installed new gaskets & Diaphragm on the fuel pump. I still need to check the Spark in a 3 Plugs. It is RUNNING but I think that it Idled better before.

 

[Kapt Bobby]

My 1979 70hp Motor is up and RUNNING vrty good again. There is a small Flat Spot Mid Throttle ,but I can jump past it

 

[Kapt Bobby]

Still running GOOD.

 

[jimmbo]

So what was corrected/fixed so as to make it run better?

 

[Kapt Bobby]

So what was corrected/fixed so as to make it run better?

Rebuilt Carbs and Fuel Pump