Engine Troubles 50 HP Yamaha 2 stroke

[Da Bay Bye]

Looking for suggestions with my 2 stroke 50 HP Yamaha. Started have some rough running last month that morphed into loss of power at full throttle. Suspected it was a fuel problem so I put some new gas in and it seemed to cure the issue. Next time out it ran great for 30 minutes but then really lost power at throttle to the point the best I could do was about 5 knots.

I replaced the fuel pump, all hoses and tank fittings and disassembled the carbs and cleaned the jets. Now the engine does not get fuel at all. Disconnected the outlet on the fuel pump and nothing pumping. Squeezing the primer bulb will not get hard anymore even with new hose setup. The engine will fire right up if fuel is squirted in the intakes.

Compression check shows 130 on all 3 cylinders with lots of spark at the plug. I found that the hard way after my finger touched the metal part of the pliers putting the boot back on.

Thanks in advance for any suggestions.

 

[scott craven]

Sounds like you're sucking air into the fuel system.
check the bulb to make sure the arrow is pointing in the right direction.

 

[Fox]

Portable fuel tanks or a built in tank?

 

[Da Bay Bye]

Portable tanks, new tank fittings and new tank to motor fuel line and bulb. I even changed the engine side fitting to ensure all was new.

 

[Da Bay Bye]

Sounds like you're sucking air into the fuel system.
check the bulb to make sure the arrow is pointing in the right direction.

WITH GREAT EMBARRASSMENT, I have to confess I made a very basic mistake. I put the primer bulb direction the wrong way. I just assumed it was like my old hose, short end to the motor and I did not check the arrow direction. This new fuel hose is just the opposite, short end is down by the fuel tank. Motor is now running and I will have to plan a test run to see if all is well.

Thanks Scott.

 

[Fox]

Everyone makes stupid mistakes. At least you figured it out yourself instead of going to a shop. Hope she runs tip top now.

 

[scott craven]

Glad you sorted it out !

 

[ericl]

Wish all my stupid mistakes were that easy & cheap.

 

[Pineapple Express]

You've learned lots about your motor and fuel system, and have fresh parts in there to boot. Seems like a success overall to me!

 

[profisher]

As I was reading down I was guessing the fuel lines on the fuel pump got reversed. Glad you are up and running.

 

[Da Bay Bye]

After changing everything from the fuel pump to the tank including all new fittings and cleaning the carbs and replacing spark plugs I got no where.
I got my issue solved today through Parker Marine in Courtenay.
Turns out it was a bad coil that was the culprit. It was slowly deteriorating and producing less spark to that one cylinder. The engine now runs better and quieter than when I bought it.

 

[profisher]

What I found with the older 2 strokes (as they are all old now) it isnèt actually the coil itself but the end of the plug wire that goes into the plug boot. Hidden corrosion builds up over time and the current either is reduced or intermittent and finally cut off here. I fought this for awhile on my engines with coils acting up and finally pinned it down to the plug wire and boot. I replaced all 6 plug wires and boots with new and plugged them into the old coils...problem solved. Cheaper than throwing out good coils!

 

[fshnfnatic]

What I found with the older 2 strokes (as they are all old now) it isnèt actually the coil itself but the end of the plug wire that goes into the plug boot. Hidden corrosion builds up over time and the current either is reduced or intermittent and finally cut off here. I fought this for awhile on my engines with coils acting up and finally pinned it down to the plug wire and boot. I replaced all 6 plug wires and boots with new and plugged them into the old coils...problem solved. Cheaper than throwing out good coils!

Good info here,Pro.I've had intermittent troubles in the past with the 2 strokes I've ran so I'll remember this.

 

[profisher]

Thinking more about this I bought just the boots and not the wires. The wires are fine...the boots just pull off the wires as they are held by a sort of spike that impales the wire. Simply push the new boot onto the old wire..the spike will set itself into the into the wire...very simple.