Yamaha 200 HDPI dies, goes when ball is pumped

[rwerner43]

27' Grady White, twin Yamaha 200 Saltwater Series 2 HDPI engines.

She started losing power in the Starbord engine. I would stop, wait a minute, re-start and she ran fine for 30 minutes, then the same would happen.

Changed inline fuel filters and on motor fuel filters.

Then at the reef port engine would not start. She had not been on the charger a few days befor and had to start the port with a jump that morning, but when this has happened once or twice in the past, she would charge up on the way out. Batteries are 6 months old.

Starboard started, got up on plane for 10 minutes, then lost power as before. Re-start, would only run at 2500 rpm. Ran for an hour. Then died. Re-started, ran for 15 minutes, died. Restarted, ran for 5 minutes, died. Wouldn't re-start.

Changed batteries both engines started, both at a lower RPM, 500 as opposed to the usual 700. Noticed the ground from the port engine was off (maybe never connected), connected it to the port battery.

Took her out, ran 10 minutes, started to die, pumped ball and got power back, ran 15 minutes, same three more times during an hour run. Batteries charged from 12.7 volts to 13.4 during this trip.

Port ball pumps hard and fuel filter on motor fills. Starbord ball never pumps hard, and fuel filter on engine has 1-2 inches of air at top.

Fuel pump?

Thanks for any advice.

 

[kissmywake]

Re: Yamaha 200 HDPI dies, goes when ball is pumped

Try to isolate the problem to the motor or the controls\fuel. Start by switching fuel hoses. The best thing to do would check for any codes. You can do this by going to the dealer or using command link gauges if you have them.

 

[cousinabe]

Re: Yamaha 200 HDPI dies, goes when ball is pumped

The starboard motor sounds like you have a fuel pump problem.

What is the maint history on your motor?
Low pressure fuel pumps, VST filter, pressure reg screen, medium pressure filter, inline check valve removed, thermostats, water pump, tech bulletins, etc?

the Z motors are run at the ragged edge of lean to start with and wont tolerate much of anything going wrong and they will detonate a piston.

Here are some good posts on the Z motors pertaining to maintenance items.

http://forums.iboats.com/showthread.php?t=200330
http://forums.iboats.com/showthread.php?t=291099

If you plan on being a Do It Yourself'er, you must get a factory manual and test equiptment.

The port motor sounds like it has a battery, loose connection problem. Check your ground cable.

 

[Mas]

Re: Yamaha 200 HDPI dies, goes when ball is pumped

Improved performance after pumping fuel line bulb is classic fuel pump issues.

MAS

 

[wayneo99]

Re: Yamaha 200 HDPI dies, goes when ball is pumped

Starboard motor: pump primer ball and listen close to the mechanical fuel pumps, you may have a tear in the diaphram. I was able to hear it swoosh each time I squeezed the ball which never got hard. Pulled the top pump and it was torn.
Not the best way to diagnose but I was lucky on that one.

use the forum and search, you should be able to find this topic easily.
good luck

 

[rwerner43]

Re: Yamaha 200 HDPI dies, goes when ball is pumped

Looks like that was it Wayne.

The ball would not get hard and when I tried to turn it over gas was coming out of the exhaust.

This was due to a broken diaphram in the fuel pump, and the gas was passing into the crankcase.

It was the top pump as well. I replaced both fuel pumps and the ball got hard in 4 pumps. I have not taken it for a sea trial, but i will let you know. Thanks everyone. She started right up and the problem seems fixed.

 

[rwerner43]

Re: Yamaha 200 HDPI dies, goes when ball is pumped

OK, so here is the follow up.

Looks like the electrical problem was a coincidence.

Turns out both upper low pressure fuel pumps had torn diaphragms, both lowers were fine.

After finishing the starboard engine, the port magically started exhibiting the same loss of power issue. Replacement of both lower low pressure fuels pumps did the trick.

If your ball does not pump hard quickly, or if you lose power at high rpm, take a look at the pumps. They are easy to get off and inspect the white diaphragm for tears. Replacement is only $50 each for new ones and far less for new diaphragms.

My Grady is running perfect again. Thanks everyone.