Yamaha 4hp 2stroke prostrate problem

[Dougy]

My Yamaha 4hp 2 stroke outboard is fantastic but pi**ing useless at the moment. No tell tale at all.
Stripped down bottom leg and changed impeller, inserted Lawnmower chord into tell tale hole and still nothing looked on web for the last three hours and all I can find is a reference to take off the head but my manual doesn't give instructions for doing this.
Anyone know how to access the waterways under the head or any ideas what else it could be? I have checked the water pump hose fits onto the tube that goes to the head and I did blow up this tube and nothing (but not sure if it should be free) but my guess is the waterways are blocked under head? How do I get to that area?

 

[VicS]

Re: Yamaha 4hp 2stroke prostate problem

My Yamaha 4hp 2 stroke outboard is fantastic but pi**ing useless at the moment. No tell tale at all.
Stripped down bottom leg and changed impeller, inserted Lawnmower chord into tell tale hole and still nothing looked on web for the last three hours and all I can find is a reference to take off the head but my manual doesn't give instructions for doing this.
Anyone know how to access the waterways under the head or any ideas what else it could be? I have checked the water pump hose fits onto the tube that goes to the head and I did blow up this tube and nothing (but not sure if it should be free) but my guess is the waterways are blocked under head? How do I get to that area?

You dont say what year , but Yamahas dont vary much

If I was doing this "blind" I would take the lower unit off first, because it may make reassembly easier if this is refitted last.

Then unbolt the power head from the leg to expose the water channels. at the top of the leg

Depending on what you find you may have to take the cylinder head off to unblock that also the exhaust manifold inner and outer covers..

You will hopefully find that one of the manuals at http://162.144.28.33/lib/library.html# will cover your engine