1992 90 hp yam tlrq two stroke outboard

[swaps2]

1. is there a tech proceedure for replaceing fuel pump and oil pump in a 1992 90 hp tlrq two stroke outboard?

2. wot for this engine is 4500-5500 rpm i can only reach 4400 trimed out i have compression tested ok cleaned carbs installed water seperator installed new cdi mod and new spark plugs the prop that is on engine is a 3x13x17 i know i can step down in pitch and gain rpm but i should be able to get aleast 5000 rpm with this prop what do you think is the problem? confused in santa cruz ca

[99yam40]

A repair/service manual will give you the necessary steps for working on the motor.

Have the motor tested with a Yamaha test prop to see it it is running properly. If it is then look at boat/motor set up and prop. If it is not fix the motor

[liam45]

I think you require a service manual where it is given all the steps for working the motor.I hope it wil help you.

[swaps2]

anyone else with any ideas besides buy a service book looking for trouble shooting ideas thinking maybe fuel pump? already have service book weak trouble shooting section

[99yam40]

Look at the frequently asked question section at testing the fuel system

[jonp]

The fuel pump is very easy. You can buy it as a kit and it screws/bolts on... simple.

Why do you want to replace the oil pump? If it works, changing it will not improve anything... If you do replace it you will need to bleed the air out of the system. BTW those pumps almost never go bad...

Also what kind of boat is this on? As a frame of reference I run a 90 Yamie on a 17ft Boston whaler. I can squeeze 5200 RPM with a 19 inch steal K series...

[99yam40]

Look at the frequently asked question section at testing the fuel system

Sorry, thought it was a different forum.
But look at this and see if it will help.
HOW TO: Testing your boats fuel system. - iboats Boating Forums

[swaps2]

1992 90 yamaha

ive ordered a new fuel pump and gasket from yamaha will arrive on july 1 will install and see if that will improve my wot problem this is a older engine i bought from a friend needed more power for waters i fish due to waves current and chop
the type of boat engine is on is a 1992 fif**** and a half foot livingston cat center console boat with twin planning hulls the prop that is on engine i think is a 3x13x17 there is a 17 k stamped on prop i think it a yamaha prop but i can only get 4400 to 4500 rpm`s out of motor the tech man say wot is between 4500 ~5500 wot would like to try and get rpm `s back so i can try and get a 3 or 4 blade ss prop with a 18 or 19 pitch on her
i have installed new tank new gas lines new water seperator cleaned carbs(3) installed new cdi mod and new spark plugs had other issues with engine but solved those with new parts i just mentioned but this new problem is not being able to get wot correct hoping new fuel pump is the anwser just bought entire pump and gasket becauseit was twenty buck more than just getting diapharms thanks guys for help on this issue

[99yam40]

Like I said before
Have the motor tested with a Yamaha test prop to see it it is running properly. If it is then look at boat/motor set up and prop. If it is not fix the motor

[robert graham]

If it used to run 5500 and now only 4400, then the problem is with the motor, not the prop,boat, set-up. Did it ever run 5500RPM's before?

[swaps2]

no new used motor trying to get max rpm so i can prop it to my likeing gonna try fuel pump next for rpm fix cleaned carbs new plugs new cdi unit had carbs sinked and installed new water seperator thank you for your advice