Originally Posted by Mark rsa2au
I am now over this POS!
Today ran the boat on the lake, Fathers day over here and a very nice spring day to get out on the water.
Last few weeks checked everything I can think of. Fuel pressure ( on trailer 30psi and on lake full throttle approx 30 PSI across the range). Timing at 10 degrees as per manual. All sensors checked or replaced. Plugs, leads, distributer and rotor replaced. Battery cables and connections replaced, earth connections cleaned and checked.
Boat starts first time every time. Dash guage shows temp slowly warming up to 160 and stays there give or take slight movement. Then the engine check light comes on so I disconnect the switch ( note this is just the on off switch- set to 180F- to the check engine light not the temp sensor).
Boat is now running rich again... on occasion have black smoke (replaced everything related so far except ECU), and will still not run above 4500rpm with out spluttering and poping or misfiring. Below this it pulls like a freight train.
Then the water intake hose splits at shower connection, and we almost sink...water over the floor boards. Lucky we now always cary tools on the Disastercraft, so wrap plastic and race tape (strong Duct tape) arround the pipe and carry on. No apparant dammage to motor dispite not having water. ( did not care anyway I'm so over this thing) Impellar checked and all good.
Guages still work on and off when they feel like it. Oil pressure guage now no longer works after today. Speedo's still slow to react and still leak from below dash (have replaced with new tubes as well).
Used a full tank (32 gallons) in just short of 3 hours measured on Tacho. Mainly water skiing, some wake boarding and a couple of tube rides. Boat cannot get to barefooting speed so we cannot foot behind it.
Finally the check engine light came on at the end of the day and stayed on, we were worried it would not restart so we left the engine running untill we put it on the trailer. Now parked on the verge as I could not be bothered to park it in the garage. No I have not checked the code yet..
The Disastercraft is THE most unreliable boat I have ever owned ( 5th boat). I have never had to work so hard to get a boat to run properly especialy one with just 270 hours on it.
Of course the Malibu in the team keeps purring along perfectly as it has done for the last 5 seasons, and the Australian made Sleekline (also 350 chev motor) still runs like a Swis Watch after 20 years. We can no longer ski our favorite spots because the family are scared the Disastercraft will break down and not get us back.
Does anyone have any ideas on what to check/replace next? Or we will have to trade it before summer.
If you aren't the original owner, it's very possible that something happened before, that's causing your problems. MC used the same engines as Malibu/PCM/Mercruiser/Volvo-Penta and any other brand with a Chevy and Indmar supplied then to MC and Malibu, so it's not an inherent problem with that. The speedo(s) leaking is usually caused by not purging the water out of the tubes at the end of the season and if the temperature drops below freezing, the water damages the diaphragm in the control box for the gauges. Once the water gets in, the electronics fail- this gauge package is common and these problems occur with all of the brands using it, but we don't see the incidents because most of us aren't exposed to them. A hose splitting is odd, but if the oil cooler (IIRC, it's after the raw water pump on your boat) is clogged, it could cause this.
The temperature sender for the gauge has nothing to do with what the ECM sees, or the check engine light. The coolant temperature sender with yellow/black wires is the one you need to check and I suspect this sender is behind the black smoke/rich/check engine light.
I don't remember if we discussed checking for codes, but that's the first thing needed now.