2001 Yamaha 150hp timer base?

[Nicktr23]

Hi, i need some help on my yamaha 2001 150hp v6. I normally work on Johnson outboards and more familiar with it than with Yamaha. I notice that when the engine is off and i advance the throttle to wide open, the timer base lever does not move at all.
The motor lately has no problem starting and idling. But when you advance the throttle, the engine does not go pass 1500 rpm and wants to stall. I believe the problem is the timing base does not move at all. Is the timing advanced electrically? Or is there corrosion that probably prevent movement. I tried really hard to try and move the lever with the ball joint off and still no movement. I didnt want to use too much force as i wasnt familiar with this brand and wanted to ask before moving forward. Thank you for your help

 

[rejesterd]

On these engines, timing is all handled by the computer which receives a signal from the pulser coil. I don't think they're meant to be adjusted manually.

I can tell you that the service manuals are quite good for these engines. Expensive, but worth it (yamahapubs.com).

From what you describe, it either sounds like a throttle linkage/synchronization issue, the carbs need to be cleaned and rebuilt, or low compression in the cylinders.

I would confirm the compression is good. Then get the service manual and go through the link/sync procedure. If it still happens after that, get the rebuild kit for the carbs and go to town.

 

[scoflaw]

Yamaha went with computer controlled timing with the fuel injected OX66. You have the old style mechanical advance, and that base should move with the throttle arm in your pic. The manual shows how to set it.

 

[rejesterd]

Thanks scoflaw. Do you know what year Yamaha switched? I was just looking at a parts diagram before, but I didn't realize it's a CDI only, not an ECM.

 

[scoflaw]

Not sure, they may have run both carbed an fi concurrently. My 2001 OX is fuel injected.

 

[Nicktr23]

Yamaha went with computer controlled timing with the fuel injected OX66. You have the old style mechanical advance, and that base should move with the throttle arm in your pic. The manual shows how to set it.

I agreed with you that it is a mechanical advance as i see stoppage on both end. One for idle and one for full advance. When i advance the throttle wide open with the engine off, the timing does not advance at all. And that is why the engine behave the way it did on the water. With the ball joint off, i couldn't get the pulser coil to move. I believe something is corroded or seized that is preventing that base from rotating/move. I will find out today after removing the flywheel. Any tips on this? I hope it'll be easy to do.
as far as carb and fuel related problem. that was my initial thought as well. I checked fuel diaphram and it is good. Removed the screws for fuel pump and squeezed primer bulb, no fuel gussing out the backside of the pump. Fuel is getting to the carburetors. But...once i figure out why the timing is not advanced, i will definitely look into carb if the issue doesnt go away.

Btw, the engine is a 2001 yamaha 150 txrz .

 

[scoflaw]

Borrow a puller from Autozone. Same puller as a Chevy harmonic balancer. 3 screws into the flywheel

 

[Nicktr23]

I just wanted to provide an update. I was able to remove the flywheel with a little brute force. The socket i used was 1-1/4 for the flywheel nut. I did some research and the consensus i got was the socket size should be 36mm. But it wasnt and based on the conversion chart, 36mm is bigger than 1 5/16. I just wanted to throw it out there just in case it will help anyone else.
After the flywheel was removed, i removed the stator and then the 4 screws holding the pulse coil. It was still very difficult to move the pulse coil. It took some time but we were able to slowly/carefully pry off the pulse coil. The mechanism is definitely the same as my Johnson motor. I dont know why it was stuck. I didnt see much corrosion but nonetheless it was stuck!!! After some cleaning, i oiled up the parts to make sure it moves freely and reinstalled. Test the motor on the muff and everything is good. We will do a sea trial tomorrow and i hope this was the culprit for why the engine had hard time planing and going WOT. thank you everyone for your input.