2002 Yamaha 200-HP Stalls

Repair or modification of Boston Whaler boats, their engines, trailers, and gear
fina
Posts: 66
Joined: Mon Dec 21, 2015 11:03 am

2002 Yamaha 200-HP Stalls

Postby fina » Sun Oct 16, 2016 9:26 pm

Several times I went to use [a 2002 Yamaha 200-HP Fuel Injection outboard engine] and it would bog down and eventually stall out. I tried opening the drain valve on the [vapor separator tank] and pumped the [fuel line primer] bulb a few times to run out gasoline. Each time that I did that the [2002 Yamaha 200-HP Fuel Injection engine] ran fine.

[Seeks] ideas as to what is happening.

User avatar
Phil T
Posts: 1049
Joined: Thu Oct 22, 2015 6:08 pm
Location: Was Maine, now Kentucky
Contact:

Re: 2002 Yamaha 200-HP Stalls

Postby Phil T » Mon Oct 17, 2016 9:49 am

Check:

--fuel for dirt and water,

--primer bulb for air leak,

--filter in the VST for obstruction, and

--all vent, fill and supply fuel hoses for integrity.

Replace any suspect hoses with new alcohol-resistant hose.
Member since 2003
1992 Outrage 17, 1992 Evinrude 115

jimh
Posts: 6616
Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula
Contact:

Re: 2002 Yamaha 200-HP Stalls

Postby jimh » Mon Oct 17, 2016 10:04 am

If the engine stalls and shuts off slowly, the cause is usually fuel starvation. Check the fuel system for an obstructions.

porthole
Posts: 599
Joined: Tue Oct 27, 2015 9:57 pm
Location: Jersey Shore

Re: 2002 Yamaha 200-HP Stalls

Postby porthole » Mon Oct 17, 2016 11:21 am

2 stroke or 4 stroke?
Thanks,
Duane
1999 Outrage 21
1999 Yamaha SW Series II 200

fina
Posts: 66
Joined: Mon Dec 21, 2015 11:03 am

Re: 2002 Yamaha 200-HP Stalls

Postby fina » Mon Oct 17, 2016 12:20 pm

2 stroke--also, as stated, as soon as we pump some gas through it starts working ok--boat has brand new [fuel] tank and hoses.

porthole
Posts: 599
Joined: Tue Oct 27, 2015 9:57 pm
Location: Jersey Shore

Re: 2002 Yamaha 200-HP Stalls

Postby porthole » Mon Oct 17, 2016 1:59 pm

I'll post some more pics later, but this will give you a start.

The Yamaha two-stroke-power-cycle outboard engines have several items considered maintenance besides spark plugs. First, there is inspection and cleaning of the vapor separator tank filter and the vapor separator tank. Second is replacement of the low-pressure fuel pumps.

The VST fuel pump filter is a pricey plastic screen that snaps on to the bottom of the fuel pump. The tank can get muddied up apparently from use, clogging the screen.

The low pressure pumps have a diaphragm inside that can fail.

My engine would run fine at speed, but after idle speed running the engine quit. Two bulb squeezes and it started right up, no problem for a couple of hours then a repeat. Again, two squeezes and fine until I was idling up to the first of four bridges I have to transit.

Two things I noticed wre the the prime bulb would not get hard, and, when I was doing this in my driveway, I found a yucky oily mess coming out of the prop hub along with raw gasoline.

The VST tank and filter and the low pressure pumps have a user-group recommendation of just changing out the pumps and cleaning the tank and filter every three seasons.

The VST tanks needs an O-ring replaced. There are three bolts, two medium pressure fuel lines, a few other rubber hoses, and two wires; and the tank is off.

A bunch of screws and the tank is separated.

The fuel filter twists off the bottom of the pump.

NOTE; the fuel line pressure first has to be bled down, and the non-reusable fuel line clamps are not a standard PEX clamp--although they look close in size.

Figure [on performing the above procedure] along with three-year service of the thermostat and poppet valve.

[LINKS to part sources]
Gasket = http://www.simyamaha.com/Yamaha_Vapor_Seperator_Float_Chamber_Gasket_p/66k-14984-00-00.htm

Filter element = http://www.simyamaha.com/Yamaha_Fuel_Filter_Element_p/65l-24563-00-00set.htm

Engine mounted low pressure pump KIT = http://www.simyamaha.com/Yamaha_Fuel_Pump_Assembly_p/6e5-24410-03-00kit.htm

Pressure fuel line clamps = http://www.simyamaha.com/Yamaha_Fuel_Hose_Clamp_p/65l-24387-00-00.htm

Expensive plastic fuel pump filter (cleanable) = http://www.simyamaha.com/Yamaha_Fuel_Pump_Filter_p/66k-13915-00-00.htm

Another item if you have the old, prone to breakage plastic trim lever = http://www.simyamaha.com/Yamaha_Cam_Trim_Sender_Kit_p/99999-03830-00.htm

Vapor separator tank or VST

Image

VST pump filter with some debris. I used Brakleen and a parts cleaning brush with plastic bristles.

Image

Low pressure fuel pumps

Image

Failed pump diaphragm

Image

This is about a 1 hour repair.
Last edited by porthole on Thu Oct 20, 2016 8:23 am, edited 1 time in total.
Thanks,
Duane
1999 Outrage 21
1999 Yamaha SW Series II 200

jimh
Posts: 6616
Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula
Contact:

Re: 2002 Yamaha 200-HP Stalls

Postby jimh » Mon Oct 17, 2016 5:01 pm

PORT'--that is a great reply. You have given a boat-load of information. Thanks.

User avatar
Don McIntyre - MI
Posts: 95
Joined: Fri Oct 09, 2015 4:33 pm

Re: 2002 Yamaha 200-HP Stalls

Postby Don McIntyre - MI » Tue Oct 18, 2016 11:32 am

Aside from Port's excellent advise and images, I'll add mine. I have a 1999 200 Saltwater Series. I don't know if they changed over three years. Experiencing the same type problems, we traced the cause to a pretty shot pump diaphragm. While the engine is apart, also check the O2 sensor to see if the hole is carboned-up. We cleaned it out, rather than replacing.

Regards - Don

porthole
Posts: 599
Joined: Tue Oct 27, 2015 9:57 pm
Location: Jersey Shore

Re: 2002 Yamaha 200-HP Stalls

Postby porthole » Wed Oct 19, 2016 10:38 am

This picture:
Red arrows are the three bolts that have to be removed. There are washers behind this that will probably fall off.
Blue arrows are the two medium pressure fuel line clamps that have to be removed after bleeding the pressure off. Be careful with removing them. I use a small pair of end cutting wire cutters.

Red wire ties are either vacuums lines or low pressure pump fuel lines that have to come off. There is also one small vacuum line behind the VST that you will see when you unbolt it.

Yellow arrow is another fuel filter that you should consider changing. It is also a water separator. The red ring on the bottom is a float for water.


Image


Blue arrows are the two low pressure fuel pumps, 2 bolts each.

Image
Thanks,
Duane
1999 Outrage 21
1999 Yamaha SW Series II 200

porthole
Posts: 599
Joined: Tue Oct 27, 2015 9:57 pm
Location: Jersey Shore

Re: 2002 Yamaha 200-HP Stalls

Postby porthole » Wed Oct 19, 2016 10:58 am

My take on how these pumps work and why they may be prone to failure.

This picture is the pump disassembled looking from the outer side towards the block.

Image

Left to right:
Block to pump gasket
crankcase side of pump chamber
pump diaphragm (with spring seat in the center)
valve block (crankcase pressure on one side, fuel on the other)
chamber seals
cover plate.

Pictured with the parts flipped

Image


It appears that crankcase pressure from the pistons moving up and down would pressurize the backside of the clear diaphragm.
The spring on the backside of the valve block pushes the diaphragm back.

The clear diaphragm pushing and pulling through the two sets of reed valves in the valve block will move fuel on the opposite side of the block through the lower and upper chambers. Fuel in from supply (bottom - suction) fuel out to VST tank where it is filtered again and supplies the $500+ dollar high pressure pump.

Thats a lot of flexing for the plastic diaphragm, and ethanol no doubt is not friendly to it's composition.

So I can see a good reason to use ethanol free or stabilized fuel, a pre-outboard spin on type fuel filter, regular maintenance of the engine mounted fuel filter and the inspection and cleaning of the VST tank and filter.

You can buy the seals and gaskets for the low pressure pumps and rebuild them, but cost wise it is a better option to just replace the entire pump. One of the nipples on my pumps broke when taking the fuel line off. No doubt the heat can make the plastic brittle.
Thanks,
Duane
1999 Outrage 21
1999 Yamaha SW Series II 200

porthole
Posts: 599
Joined: Tue Oct 27, 2015 9:57 pm
Location: Jersey Shore

Re: 2002 Yamaha 200-HP Stalls

Postby porthole » Wed Oct 19, 2016 11:04 am

Don McIntyre - MI wrote:Aside from Port's excellent advise and images, I'll add mine. I have a 1999 200 Saltwater Series. I don't know if they changed over three years. Experiencing the same type problems, we traced the cause to a pretty shot pump diaphragm. While the engine is apart, also check the O2 sensor to see if the hole is carboned-up. We cleaned it out, rather than replacing.

Regards - Don


Here is what the gasket set looks like on our 1999 SX 200's. These would be needed if cleaning the O2 sensor.
The actual O2 sensor kits are also very expensive with these outboards. Cleaning first is a good option to try for the cost of gaskets and time.

http://www.simyamaha.com/Yamaha_Oxygen_Sensor_Gasket_p/68f-w1135-00-00.htm

Many of these parts are similar throughout the Yamaha line. The low pressure pumps cross reference to quite a few different applications, including motorcycles.
Thanks,
Duane
1999 Outrage 21
1999 Yamaha SW Series II 200

porthole
Posts: 599
Joined: Tue Oct 27, 2015 9:57 pm
Location: Jersey Shore

Re: 2002 Yamaha 200-HP Stalls

Postby porthole » Tue Nov 22, 2016 12:10 pm

Last week I finally got out to test my boat. No surprise the boat ran fine all day which included about 4 hours of trolling just off idle.
It wasn't till the next day my partner at work mentioned that when his mechanic did the same repair to his boat, the mechanic told him it would feel like a different engine.

Then I realized that when I was cruising at 23-24 knots my engine speed was about 3400-3500 rpm, 600 rpm lower then my normal cruise speed of 4000 rpm. That and it seemed that my fuel burn rate was lower as well, although I hadn't been taking notes on fuel consumption. My overall fuel usage for the day was less then normal, but I also spent a lot of time trolling instead of traveling and stopping.

Either way, changing these pumps will now be an every two year maintenance item.
Thanks,
Duane
1999 Outrage 21
1999 Yamaha SW Series II 200

porthole
Posts: 599
Joined: Tue Oct 27, 2015 9:57 pm
Location: Jersey Shore

Re: 2002 Yamaha 200-HP Stalls

Postby porthole » Tue Nov 22, 2016 12:11 pm

fina wrote:2 stroke--also, as stated, as soon as we pump some gas through it starts working ok--boat has brand new [fuel] tank and hoses.



Welllllll - did ya' fix it?
Thanks,
Duane
1999 Outrage 21
1999 Yamaha SW Series II 200