It is a 2001 model year.   A good friend passed away at 64, total surprise to all of us.   His wife called and needs to sell this boat.

Her first buyer took it for a test drive and it would not go over 5 mph.   They put it in a shop and are told it has engine problems and they plan to replace all the fuel injectors for the discounted price of $2,000 but they don't know if that is the problem for sure, and then said the outdrive will need another $2,000 invested.   She called for help.  I will pick it up Thursday Morning and hope to be able to help her fix it so she can sell it.   That is the before story.   I am hoping someone on our forum has experience with the 502 marine fuel injection to point me in the right direction.

I will start with a battery test and then go straight to the fuel pressure and start chasing this down.

I am told it sat for a couple years but they did a lot of work to it before it sat and took it to Lake Powell in Arizona for a Houseboat trip where it ran really good.

The wife was in tears, the boat should be worth $22 - 26K if working well and the first guy offered $5,500.

I know engines pretty well, good with automotive fuel injection but know nothing about the GM Marine fuel injection software.

I have never worked on an outdrive.   I think I may change the oil in it and after fixing the engine put it in water and see what else is needed.

I promise to wear a Ski Nautique shirt when I pick it up at the Marine Shop and while I work on it just to keep the faith.

In pictures this looks like a very nice boat but I have no interest in ownership, just going to help her get it running to sell it.  We have been friends for 40 years so I need to help.  Now I just don't want to fail on this project!

I'll check back in when I know more and to beg for help or therapy.

Mark

I agree that you are fantastic to help this friend in need. I wish you the best and do post what you find and I know we will do our best to try to help as well.  

At whatever the manual costs, I figure it's worth the money

And...............when you're done and she's selling the boat, a dirty, used looking factory manual is a good selling point 

This boat is much heavier than a Ski Nautique, my Yukon felt it.  Got 10.4 MPG towing at 60 MPH almost all freeway.   I think full dressed with trailer it is close to 6,000 pounds.   Nothing fixed just investigating but it is too hot on my driveway to spend much time.  Won't fit in my garage, way too tall with the tower on it. This boat has a bathroom hidden under the dash and in front of the passenger seat.  You would have to be an acrobat to use it and willing to put all out on display, but it has one.

I started it and it is running on 3 cylinders.  I was told it had a compression test done and all 8 checked good.  430 hours I think I saw.  Might be plugged injector or a injector wire issue.  I plan to spray gas I tonight and see if the dead 5 cylinders fire up.

Neither one would have fixed this boat and they got the extra $460 for advising it needs new injectors.

I learned the computer uses two wire feeds for the injector signals out, one for each bank.  Bank one is dead so I need to find out why.  The one plugged injector was on bank 2 leaving me with 3 cylinders working.

The Marine shop is a reputable shop but had no clue how to diagnose this boat and planned to charge much more to TRY to fix it.

For $150 per hour they should be much better than that.

I hope to figure out the electrical but I’m weak on electrical.

I know I should have checked fuel pressure but there is no port on the fuel rail.  I will revisit fuel pressure if getting all 8 injectors working does not fix it.

The manual is a GM thing and since they (PCM, Volvo, Mercruiser etc all buy their engines from the same place the manual should tell you everything you need to know about the engine including wiring diagrams.

You'll just have to figure out if it's MEFI 3 or MEFI 4 for example 

BKH

I was told the boat was empty of gas and they had put 15-20 gallons in to do a water test when they found it would only go 5 mph.

I did a fuel test before starting it with clean injectors and it pumped brown gasoline.  I hooked up a gas can to the fuel feed and cycled the pumps a few times to fill with fresh gas.

Turned the key and bam.  Fired on all 8 and sounds mean.

Thanks to all of you for the help.   I read that this 8.2l or 502 GM marine pushed the Cobalt 29 foot to 51mph.  This boat is only 24.5 so I bet it is fast.

Looking at the dash it has a perfect pass installed?  Seems odd.  It does have a wakeboard tower.

I plan to go back and check all 8 cylinders to verify it is an 8 cyl again but it sounded really nice.

Only a load will tell for sure.

Now, how do you dispose of 40 gallons of bad gas?  I will check locally with our city.

The shop was correct in saying the injectors were bad so I publicly apologies even though I did not use their name.

Mark,

I think you should take it back to that so called marina where they weren't sure how fix it. Feel free to use my terminology and call their mechanic a "back yard hack". 

I will try and post the pic of the gasoline I pulled from the boat.   I used two small buckets, one has clean gas the other with the brown fuel is the bad gas, after 15-20 gallons of new fuel were added to  it.

I have a tube that fits on a can of Carb Cleaner and the tube is modified to fit the injector opening.

Separately I have a can of WD40 set up with the same type tube.

Finally I have an old style hand pump oil gun filled with ATF fluid and it is also modified to fit the Injector opening.

First step you apply power and spray through the injector into a container, I use a small bucket like the ones above holding gas.  Put a couple clean white paper towels in the bottom of the bucket.  

Spray the carb cleaner into the injector while it is powered with 12V.  12V should open the injector.  Watch the spray pattern. When it sprays with a nice spray pattern it is working and clean, if it is dripping/ not spraying or no spray it is bad.  If bad let the carb cleaner work for a minute or so and apply again.

Carb cleaner is pretty abrasive so as soon as they spray clean I spray again with WD 40.

Last step I take the hand pump ATF and pump ATF through the injector, it cleans and lubricates the internal parts so they are not damaged by the carb cleaner.   

Last step hold the injector close to your ear, I have the wires plugged in and about 2 feet away is my battery connection so I can reach out and take the positive lead on and off the battery, touch it quickly many times and listen, the injector should open and close as fast as you touch power and release.  

You will see any junk that blows out the injector on your white paper towel in the bucket and the bucket catches all the excess spray and drips.  The oils and cleaner soak through the paper towels and any mess that comes out sits on top.  It is fine particles like black dust normally.   Use a new paper towel for each injector cleaned and you will see what comes out and how the spray pattern changes from bad to good.

Backyard mechanics for sure but guess what, it works pretty well.   There are several youtube videos out there showing several ways to do this.

I have an engine Oiler that holds 5 quarts, you can pressurize this tank and it has a feed hose and a valve to regulate flow.  It can hold over 100 PSI.  I have considered making a connection to this so I could do the final step blowing ATF through the injector pressurized but the old hand pump has done the job so far.

I give it a few pumps until I see the ATF dripping out the injector spray nozzle.   It takes a few pumps and you see the WD 40 exit before it turns pink and you know it is now flowing ATF.

Our City does have a Hazardous waste pick up but limited to 15 gallons and they want 5 weeks to get an appointment for the 15 gallon pick up.  We are looking for other options.  

If this was Nevada we could just burn it off.

Edit:  before spraying with the injector powered with 12V I spray a tiny bit of carb clean into the inlet, this is where the filter/screen is.  I tap the injector on a paper towel after spraying with the screen / filter down.  Hoping the kick out anything that may be plugging the screen.  Sometimes you find things and sometimes you don't but this is an important step before cleaning the injector.

On the 100 mile tow home I stopped twice to inspect the wheel bearings.  All 4 stayed nice and cool, even when I got home I checked once more, all 4 wheel bearings were nice and cool.   Has me thinking these bearings might have been adjusted this loose by a prior wrench?   My thinking is if the bearings were failing they would have been really hot to the touch.  As I jacked up the trailer I saw the one wheel tilting slightly which started this inspection.   Oh well.  Pulling off the outdrive tomorrow for new bellows and hoping not to find any more issues.   I want to get it ready for a Water test to see if the engine is working as well as I hope.  I found out the 502 in this is rated at 415 HP so it should get along really nice.

Drained the outdrive today, the oil was black and old, at least it did not have any water in it.  Progress.

The previous wheel end work had 4 seals installed that did not fit the axle although they fit the Hub.  The rubber seal was about 1/16" too large, did not even touch the spindle.  The mechanic installed 4 Speedi Sleeves on the axle and they fit the seal but were still large on the spindle so no seal, water could get in and grease could get out.  Result was not surprising.  Grease had covered all 4 Brake Shoes and the entire inside of the brake drums and all hardware.  Looks to me like the prior owner was great at filling the bearing buddy's every trip but had no idea where all that grease was going.   Took me a full day to clean up the 4 wheels.   Found the Axle nut stripped on the axle that had 2" free play in that wheel.  The axle stub was stripped.  Looked at purchasing a new axle New axle was 6-8 weeks out with no guarantee of actual delivery date.   We need to go in the trailer business, the trailer shop was telling every customer they are currently booked until January.  The threads were 13/16 -20,  I bought a 3/4 - 20 Tap and Die.   The axle threaded really nice down to 3//4-20.  I made a nut to match the other 3 in size and tapped it to 3/4- 20.   This is the same size nut and thread used on many GM trucks for the front axle spindle so I am not concerned it will not be strong enough.   So a couple days later we finally had a trailer again.

Started bleeding the brakes, fluid came out looking like mud.   Cleaned up I could see all 4 brakes had been replaced not long ago in terms of miles driven, they were galvanized and in really nice shape once cleaned but since the grease was everywhere I did not know this till it was cleaned up.  One wheel cylinder was stuck, cleaned up easy, just a little rust.  Pumped 2 full quarts of Dot 4 brake fluid through this and it started pumping out clean.  Finally, got brakes although I worry what all the grease may have done to the wheel cylinders.

Pulled off the outdrive, all the internet videos show everyone building a roll around plywood stand?  I put an eye in the top of the outdrive where the Volvo Penta book showed and lifted it with my engine hoist and it worked very well.  No problem at all.   No stand needed. Installed new Bellows and new seals on the upper and lower unit and put it back in.  This job had me scared since I have never touched an outdrive before but it really was no big deal if you go slow and be careful.  This all went back in very well.

If your remember the Injectors were plugged by running very old gasoline, I pumped out the gas in the tank, the gauge said the boat had 1/2 tank when I started, pumped out 25 gallons, gauge said I was on empty, I think great, couple more gallons.  Nope, pulled out a total of 43+ gallons.   Getting rid of old gasoline is a problem.  Some said 5 gallon limit, one said 15 gallon limit, another said for $150 and $10.50 per gallon they would take it.   My cousins son came to the rescue.  He takes old oil, Engine or cooking oil and makes his own Diesel fuel.   He said he could use the old gasoline to make Diesel and took all of it, and he picked it up and was happy to get it.  WIN WIN.

He has a station he built complete with a Centrifuge for making Diesel.  We really lucked out on this part.  I keep saying WE, most of that We was me, myself and I until the cleaning started.

We spent a day washing and cleaning everything.  I had to put a new blower vent hose in and we were ready for a boat test.

The big 502 fired on the first touch of the key and idled strong.  The potential buyer who is also the same guy that put this boat into the shop for the expensive estimates called to tell me there is no way this boat is fixed, it is going to need much more than injectors, he said he had it at several experts and this boat has real problems.  When this guy water tested the boat a month before I was involved it barely started and would not move the boat over 5 MPH.   When we got out of the 5 mph zone I powered it up and it jumped right up to 40 MPH on partial throttle.  We ran it a while and opened it up. It ran perfect and very strong.  Tops out at 4,200 RPM but I am guessing close to 60 MPH.   Dumb Correct Craft owner driver FORGOT the boat has power trim for the outdrive.   We drove it an hour really enjoying the power ride and speed, and then found the power trim, it picked up an easy 10 more MPH.  The boat owner, my friend who lost her husband recently was in tears she was so happy.  Made it all worth while but it was not a quick fix, It was a long 2 1/2 weeks.   First fixing and repairing and then cleaning, buffing etc. but it should be easy to sell.   I will try to post videos.

The bad news,  My wife has been injured for the past 30 years and riding in our Nautique or similar boats jars her neck just enough to leave her in pain that can last hours or even days.   She loved the soft ride in the Cobalt and she has always loved Power so the 502 had her smiling.   It was pretty impressive.   Hitting boat wakes even at speed just made it rock a little.  My boat would have been slamming on some of these.  I did not ski but the water was awesome.  Got to get out there and use it soon.  The bad news, she says, WE NEED A BOAT like this.   I will talk her down over the winter.  Our Nautique stays.  

The 246 Cobalt with the Duo Prop really surprised me, it handled very well, great acceleration, zero prop slip, it turned better than any outdrive I have ever been in.  I pulled a couple tight bat turns in it at speed and it did it like it thought it was a Nautique.   Moving around the Dock the outdrive is pretty cool, you can back it while turning with no effort.  It is big and heavy, bet it has a 4 foot draft and that would take some getting used to.  One of the big Nautique Air boats came out and was motoring around today, had the really wide nose on it, almost a tri hull nose?   It was not even close to the Cobalt in speed.  

Since this was the owners pride and joy, well, one of his 4 boats she chose to scatter his ashes in the lake today so it was a special day, she said he would have loved getting to go out in the boat one more time.

Thanks letting me go out of the Nautique box on our forum.   Have a great week.

Now that we know it does not have any issues I need to take it out again Saturday for a potential buyer.  Hope it sells quick, I need the space back.

Mark

You’re a good man, and you will be rewarded;-)

 

JQ