1990 150 HP staling issue

[99yam40]

fuel pump from e bay with a hole sounds like they sold you a failed fuel pump

[DennisG01]

Where exactly is this hole? Can you post a picture?

But... there is no "top" or "bottom" fuel pump - there should be no physical differences between them. Meaning, when you buy a new one, it can be mounted in either location.

Unless you're planning on getting the service manual and a vacuum/pressure tester, maybe it would be a good idea to get a better quality pump from a reputable place. I think Mallory makes them - and certainly Sierra does. Even buying the Yamaha brand isn't all that expensive.

[tuccimf1]

Thank you for your help! Much appreciated. I have reached the frustrated point and have found a Yamaha mechanic.

[DennisG01]

OK, no worries. Be sure to post back with the solution - it may help someone else in the future, but even more importantly... curious minds want to know!

[tuccimf1]

Dennis, definitely! I will let you know. Thanks again!

[MoDaddy71]

Tuccimf1 - what was the solution?

[tuccimf1]

No solution. A mechanic told me I had a bad head. Selling the motor.

[MoDaddy71]

I have a 1997 Yamaha 150 saltwater series which bogs down at high RPM or heavy load (full boat of people). Replaced fuel pumps, bulb, fuel filter and fuel lines up to the filter. Just rebuilt the carburetors. It will start and run great at revs 3K RPM or less. Once I run higher it will bog down and lose rpm fast, at that point even low RPM it will cut out. Only way to correct is to shut the motor off for a few seconds, restart and I can run forever as long as I don’t run above 3K~. I’m baffled. Please advise. Oh, new plugs too. Might put this as a new post too.

[99yam40]

No solution. A mechanic told me I had a bad head. Selling the motor.

what did he mean bad head? power head or cylinder head?
what is wrong with the head?

[tuccimf1]

Mechanic said needs a new Powerhead

[99yam40]

so you have no idea what is wrong with your power head?
seems strange to me why he would not tell you why it is bad

[tuccimf1]

He said the highest compression is 85.

[tuccimf1]

The mechanic said the compression was 85 85 75 but I recheck it and I am getting 100 100 90. Lost now!

[99yam40]

different compression gauges can read different.
question is which one if more accurate.
might find another and try that too to see if it matches one of the other readings

a 150 should have more that 3 cylinders