How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Dominick Your Own Question
Dominick
Dominick, Marine Mechanic
Category: Boat
Satisfied Customers: 1009
Experience:  25 Years Experience as Mechanic, 20 Yrs Boat Yard Owner/Mechanic, Factory Certified
14379177
Type Your Boat Question Here...
Dominick is online now
A new question is answered every 9 seconds

My 1989 Yamaha 3 cycl. has no vacuum on bottom cycl. its a

Customer Question

my 1989 Yamaha 3 cycl. has no vacuum on bottom cycl. its a 40 h.p. elef. good compression 121.123.125. pull # ***** plug wire while running, nothing happened, just keeps running, pull other plug wires and it dies. a boat shop pulled powerhead, manifold said there was a leak. resealed it, ran fine for 3 or 4 minutes, then droped #3 again. what next, new owner? I had no idea I was running on 2 cyclinders till while running wot the thing took of like it has nos in it. then slowed down again. thanks j.d.
Submitted: 1 year ago.
Category: Boat
Expert:  Jason replied 1 year ago.
Hi JD, my name is Jason.
Can you be more specific by what you mean by the bottom cylinder has no vacuum?
If you place your hand over all 3 carbs with the engine running, can you feel suction against your palm, or does it spit back at you?
Customer: replied 1 year ago.
no suction on #3 but doesent spit back.
Expert:  Jason replied 1 year ago.
So no pressure or no suction then when you place your hand over #3, correct?

Related Boat Questions