Well my search for a boat is finally over.  After looking at all the junk out there, ("all boats leak" was a classic, after we emptied over 5 gallons out in 20 minutes of time in the water).

It is a 2002, with a 150 hp 2 stroke Yamaha, and an 8 hp Yamaha 4 stroke kicker.  It has a nice shoreland'r trailer with disc surge brakes.  

I ordered a new bilge pump to upgrade it just in case.  It has a new battery, lots of canvas, and best of all, it has been stored in a garage.  There are receipts since new, and one owner.

Is there anything I need to be aware of with the Yamaha 150?  I don't read any issues with the high-pressure oil injection like I have read with the VRO system on OMC products.  It has had a new fuel pump and tune up just a week ago.  

I'm going to change the gear oil, motor oil in the 8, and add some SeaFoam to treat the gas over Winter.  Other than the bilge, the only other upgrade it really needs is a newer GPS/sonar system.  It still has a black and white 2002 Lowrance x75.

"Fog" the engine and drain the carbs. IIRC the Yamaha carbs have a drain screw on the float bowls. Grease all the zerks on the transom bracket and coat the steering cable with grease where it is exposed near the engine. Change the trim fluid mainly to eliminate any water in the system.
No problems with the oiling systems that I know of, but akethan may chime in. He's seen alot more Yamaha's than me in his shop.
Personally I would drain the gas (or as much as you can) out of the tank. I see more damage from bad gas than any other problem. Clogged carbs, bad fuel pump diaphragms, detonated engines etc.
Change the impeller annually at the beginning of the season. No sense putting in a new one to have it just sit all winter scrunched up in the housing.
Don't forget the trailer. Bearings, seals and tire condition not to mention the brake system. Keep a close eye on the fluid/master cylinder for water contamination.
Don't forget to trim the motor down so no water will accumulate in the lower unit and freeze (ask me how I know ) Pull the drain plug and elevate the bow if storing outside.
As far as the bilge pump goes, why not just add the second pump on a seperate switch. You know, two is one and one is none.

Thanks a lot for the tips KB7DX!

The gas was drained and replaced by a marina just before I bought it.  The carbs were also cleaned.  I'm going to change the gear oil as soon as Amazon delivers it.  

I read the manual about all of the places to grease.  I'll have to read up on the impeller.  I know they are cheap so that is good insurance to prevent an issue.  I didn't see anything about changing the trim pump fluid.  Is that pretty easy?  Some sort of special fluid or brake fluid?

My trailer has surge brakes with disc brakes, but I don't see a master cylinder.  It does have bearing buddies but I need to read up on how to service them.

Changing the trim fluid will eliminate water (if any) and prevent it from freezing and bursting the trim unit. Yours may not have any water in it, just sayin' it won't hurt anything changing it. I don't know if the Yamaha has a drain plug for the trim or not. At least check it and see if it looks milky (water contamination).
The trim will use specific "trim fluid", however I think it's just standard power steering fluid/hydraulic oil. NO brake fluid! Consult the manual.
The master cylinder for the brakes is inside the tounge of the trailer. There should be a cap visible through a hole in the top of the tounge.
Bearing Buddies are just large "dust caps" that have a plunger and spring in them. This setup allows the hub to hold more grease and pressurize the hub slightly to help keep water out of the bearings. I remove them by jacking up the wheel and rotating the wheel while tapping on the outer edge of the Buddy with a plastic mallot. This will "walk out" the Buddy. Then just wipe out the old grease and refill it about 1/2 way before re-installing it. Once installed, pump some grease into it with a grease gun until the plunger moves outward 1/4 inch or so. This "pressurizes" the Buddy.
I recommend removing the bearings and cleaning them while you're at it. Install new seals. If you do this on an annual basis you will be WAY less likely to have bearing issues. I see countless trailer hub meltdowns that could have been prevented if only the owner noticed all that grease slung on the boat hull/trailer wheel.
Impellers are indeed cheap insurance and easy to change once you have done it. I used to change them on the beach when I was a youngster. Had older 10 and 30HP Johnsons back then.

Great info, thanks again!

I'm trying to find a service manual for the motors but so far no luck.  Changing the impeller definitely sounds like cheap insurance.

Today I tried launching it, only to discover that the live well pump had broken off at the hose connection.  I installed a new live well aerator and pump, as well as a new bilge pump, and both are now working again.  Sadly, the wires were previously just left laying in the bilge.  I have to think they shorted out at some point.  I zip tied them up higher in the bilge area.

I used to work on airplanes a little, and the small 5-6" access hole for the bilge makes the hell hole of an airplane look roomy by comparison.  I shall try to launch it again tomorrow, hopefully with better results.  

I do have the manuals for the trailer, trailer brakes, and so on, so I will have to look some more for the master cylinder.  So far, there is nothing visible where fluid can be added or checked.

This trailer doesn't have electric brakes does it? And yes, boat builders are the kings of putting important things in small spaces. I can hear them now.."You'll never have to replace that pump, so we'll put it way back there and give you a 3 inch hole to service it...no wait..we'll put it under the engine so you have to pull the engine to replace it.."
<-------Boat mechanic here.

Bilge pumps fail at the worst possible times.  Keep the old on in the boat as a backup or better yet install 2 separate ones.

Ha, I had to look up what Cirrhosis of the River was, clever!

I have a new Rule 2000 gph bilge pump that I am probably going to take to a marina mechanic to install with an automatic float.

I did get the boat out on the water today.  Everything seems pretty good;  it will run 57 on GPS, and was very stable.

I am having one issue that puzzles me.  It was at a marina on 9/18 for work, including a new high pressure fuel pump for the 150, and cleaning of the intake/injection system according to the bill.  They also flushed the fuel, and I'm told the previous owner put in some fresh fuel.  The first 1/4 of a tank I ran through it all was good.  Once it got down below 1/2, I started having an odd sporadic miss on the 150 when under heavy load, such as wide open, or when coming up on plane.  If I accelerate very slow, it won't miss at all, but if I run it up quickly it is definitely missing.

I'm wondering if there is some bad gas still in the tank, so I'm going to check the fuel filter tomorrow.  I'll also add some seafoam to the gas.  My other thought is if the gas gauge is slightly off and it is running out of gas.  It runs fine though once under way and not under full load.  I have no idea how much it holds, but there is a reserve switch on the back of the boat.  The manual doesn't have anything in it about fuel tank size or reserve size (I found that very odd for an owner's manual to exclude that).  I also heard there is an accelerator on the carbs or intake?  Something that could be failing under load.

What I really need is to find a manual but so far no luck.

Definitely not electric brakes.  I figured out today why I can't find the master cylinder....it is covered up by a step the P.O. bolted on over the tongue of the trailer so you have a place to stand while winching the boat up.  I have to remove that step to see the master cylinder.  I have added a fluid change to my list of things to do.  I may go ahead and just change the rotors, brake pads, and grease the bearings while I'm at it.  While the boat was off the trailer I also saw that the bunks could use some new carpet.

Here is a random question.  The boat has a marine radio.  I had it on all day and didn't hear any communication.  Is there a way to test them?  It has a 3' bow antenna, and I was monitoring the coast guard frequency (16) as well as scanning the others, but there was nothing to be heard.

Ok, I'm confused now. Is this 150 a carbureted or fuel injected engine? You mentioned a high pressure fuel pump and injectors.
ETA -- To test the marine radio you can listen to it on another marine radio or a common police scanner. You may not hear a peep on it if you aren't near a major waterway or marina.
ETA -2 Installing the second bilge pump is easy peasy if you want to DIY.

The 150 has 6 carbs.  The bill says "R&R vapor tank, clean/flush ind system to get running".  I am tempted to try fogging it with seafoam and see if that takes care of the stumble under load.

It does say they changed the high pressure fuel pump ("HPPI Fuel Pump" according to the bill), $500 for the part.  I wondered if that was in the gas tank like a car would have?

Hmmm..has 6 carbs and a high pressure pump...hmm...does not compute. The high pressure pump is inside the vapor tank, not the fuel tank in the boat. Also, all the carbureted 150's I have seen use 3 carbs which are 2 barrels. Do you mean 6 fuel injectors maybe?
What's the model number of the engine (can be found on the transom bracket).

You know the rules

Post the model number of the 150.   It could be an OX66 model and have six throttle bodies.

I would add a 10 micron filter between the tank and engines. Yamaha suggests them on all new rigs.

I see you're in Indiana. I have on of two Yamaha Master techs in the state working for me.  If you need any help let me know.

The motor is a Z150TLRA.  

I put 2 cans of Seafoam into the gas, and gave it a good run again last night.  It runs great when on plane and running, unless I push the throttle all the way forward, where I get no additional speed, and it sounds and feels like it is missing.  When throttling up from a stop if I increase the throttle very slowly it won't miss, but if I run it up even with a medium speed increase on the throttle it will miss 4-5 times at least as speed climbs.  

PM sent.

The part number of the fuel pump that was replaced was:
60V-13907-00.....or it could have been 606 at the front...the handwriting is terrible!

Yep, that's a carb motor.  I'd pull the fuel QD off the 8hp and get a fuel sample in a glass to see if you have water in your tank.


Just about every bad running motor this year has had water in the fuel tank.

double tap

Well that is what my first thought was too.  I checked the clear fuel filter on the 150 and it was all gas.  The previous owner had a marina drain the tank and it was refilled with fresh gas.  I've run at least 10-12 gallons through it too.  It had 1/4 tank when I bought it, I added 12 gallons, and I'm now below a 1/4 tank again.  I can't say the fuel level has had anything to do with how it runs.

Last night I also switched it to reserve, figuring that draws gas from the bottom of the tank, which if it was a water issue, would mean more water.  It didn't run any differently.  

I am wondering if the carbs need a thorough cleaning, or if there is another issue causing it to run potentially lean or starve for fuel under high load or high RPM.

Just for fun, what spark plugs are in it?

Any guesses are good guesses at this point.

NGK BKR6EKU

Also, it is 3 2 barrel carbs.  Not 6 as previously thought.

Should be BR7HS-10

That other plug is for an HPDI model, yours is carb. Put the right plugs in it and go try it out.

The HPDI plugs are expensive compared to the HS-10s

I looked it up in the manual and this is the specified plug.

Incidentally, the side of the motor does say High Pressure Direct Injection.  I wasn't sure if that meant oil or fuel?

Pics?

HPDI is a fuel injected engine, no carburetors.  Something is amiss here.

Okay so it's an HPDI.

Change the plugs if they are not new and all the filters between the tank and injectors and clean or replace the injectors.

I was looking at it closer tonight.  I see from the parts on Ebay that what I thought looked like carbs on the outside are just intake manifolds.  Not carbs at all, although they sure looked like it to me.  Butterfly valves and all.  Filters and plugs will be easy enough.  How tough is it to find injectors?  Any idea on cost each?

Any feedback on this service?

$25 per injector.  I've been searching for fuel filters and only see one.  Based on earlier comments, it looks like I need to add another filter?

Fuel Injector Cleaning

Clogged fuel injectors will cause the symptoms you are having. There might be someone local to you that does this service so you won't have to ship them out.

Thanks KB7DX.  I ordered the service manuals and hope to get some basic information on taking the injectors out.  Removing them looks far more complicated than cars I have worked on.  I was looking for the pressure release valve on the fuel rail and don't even see it.  

I'm really debating letting a Yamaha service center take a swing at it.  I'd hate to send out the injectors for cleaning just to find out it was something else.  I see there are 2 small fuel pumps on the side of the motor, as well as some small filters that could also be the culprit.  

I have ordered a 10 micron Yamaha fuel water separator, plugs, and a new filter element for the engine fuel filter.  I have my doubts that stuff will make a difference though.

With a 9 volt battery and a home made harness you can flush out your injectors.

How?

Seeing how somebody bumped this.

We had one in last fall a Lund, I thought it was yours at first.

It was full of carbon, the whole damn motor. Cleaned it through chemical treatment and replaced the O2 sensor and some of the parts associated with it.

The biggest deal was a bad battery.  

It may not need the fuel pump and injectors cleaned or replaced.

Carbon in the exhaust ports causing restriction? We get that on our Merc 50 and 90hp 2 stroke rental motors. About every-other year I have to remove the powerheads and "mine" for carbon.
They plug up the idle relief passages mostly but I usually get about 1/2 a cup out of each engine. Our rentals see a lot of usage.