This Boat again...

SO now the fuel pump and filter have been replaced on my Mobius, took out the boat this evening..same F##cking thing, Won't get up on a plane, bogs down, and now it almost overheated-temp was through the roof, smoking more than normal also. Backfired one time. When I got back, I removed all the plugs-all were black and a couple were a little wet-not sure if it was water or fuel.. (praying it isn't water) I am bringing it back in in the AM but can anyone tell me what the hell is going on here? Glad I just spent $350. for a fuel pump I probably didn't need..

Smell the plugs black usually means gas not water. If it was water they would be white. But smell them and see if they smell like fuel. It is probably ignition system based on what you describe.

M MASTERCRAFT's
O OLD
O OBSOLETE
M MANAGEMENT
B BENEVOLANT
A ASSOCIATION

TJK, That post was helpful and very informative.

Jeff Hunter, Take your boat into a certified technician. They should be able to find and fix your problem.

is this a carb or efi?

hmmmm thats hard to call....anyone have any ideas...

Is the boat going into limp mode and you are continuing to drive it? Address the overheating and go from there. Running rich will not cause it to overheat, but things like timing will.

When was the last time you changed the impellar?

Overheating could mean that you have inadequate water flow - cause extra friction and overloading engine. Getting that corrected is first priority. Then - black "soot" on plugs is usually from running rich - to much gas. A carburator problem. If not a carb engine - could be a vacuum leak or problem with the throttle body.

TJK, very clever. Did you think of that all on your own or did your local MC dealer have to help you with it?

TJK- First of all, you mispelled "Benevolent". Second of all, it DOESN'T make any sense!!!!!! The definition of Benevolent is: for the purpose of doing good. Man, before you go rippin on someone else's boat at least do it correctly, intelligently and with the correct spelling!!! But then again....you do own a mastercraft...

Be a man and don't go the way of childish crap! People like you make wakeboarders look bad!

Jeff, make sure you are taking your boat to a mechanic not a parts changer. There are lots of parts changers posing as mechanics these days. Once in a while they will guess correctly on the first try but most of the time they end up costing your more because they just keep throwing parts at it until they happen upon on the right thing. A good mechanic should be able to diagnose the problem before they start replacing parts, if they make a mistake it should be on them.

I would agree that you just spent $350 on an unneeded replacement.


TJK it's an issue with an Indmar product, would be the same if it was a MC or Bu. I have a PCM but it could very well be the same. Most marine motors are on par regardless of boat maker these days.

Just stop posting TJK.

The guy is frustrated and you go and post that?

Jeff - sounds like your problems need a good mechanic. Us guessing at the problems may only make things worse. Sounds like horrible timing to me, but I'm guessing any mechanic would have put a timing gun on it first.

Mikeski, ya beat me to that one... Kinda funny that TJK prob has an Indmar engine in his MC...

Jeff, I had a similar problem with my MerCruiser motor in my Tige. It would idle a little rough but when I got on the gas it would never get on plane. I had several people look at it and no one could figure it out. I called an old friend of the family who was a boat mechanic told him what was happening and he new the problem right away. It turns out the exhaust gaskets went bad and that was causing the problem. I am not saying this is your problem but just confirming what Mikeski said find a good mechanic that you can trust because allot of people out there just go with what has happened before and start changing things that are still good and it adds up quick.

Have you checked your fuel filter for Water?

I love how people trash boat manufacturers when something in the engine goes wrong. Last time I checked, Moomba doesnt make their own engines. Reminds me of a friend who kept telling me how much more reliable cobalts are than other boats until I showed him that you can get the same mercruiser motors in Bayliners.

Try changing the fuel filter...you can get it for a few bucks at Autozone and it's a simple changeout. Worth a shot.

Thanks for all the input, I have changed the filter and since the pump was replaced the fuel pressure is back up. it was down to 26psi before and now it is back where it should be at 36. Anyways, the pump was probably going out also. This new problem, I believe is the impeller. I have not replaced it yet since I bough the boat and god knows when the last guy did it. As far as the plugs-not too sure there-they smell like fuel and the compression was just checked last month and was great. The guy working on it is infact a certified indmar mech, and apparently comes well reccommended. I guess we will se today.

Thanks to all for the help on this site-the wakeboarding community once again proves to be a tight circle-if I can ever help anyone I will-too bad you have to have one idiot who just uses this to talk smack about his boat!

Dave-sorry for the title in the post-was a little frustrated, didn't mean to offend anyone.

anyone notice TJK is almost 40? :-O

must be efi with fuel pressure that high.

strainer & tranny cooler blockage and impeller condition are the first things to check if it's overheating. fix that immediately. if the other problems started after the overheating, they may go away. it's also possible that the overheating has now caused other problems.

T totally
J jealous
K kind (not a kid any more your 40 grow up)

Jeff,

This might be silly, but have you verified the plug wires are in the correct firing order? Reason I says this 1) sounds like your boat is down on horse power, 2) makes sense that it would overheat.

My guess is that you have the plug wires in the wrong order, or one plug simply isn't firing and you are down a cylindar.

Your implellar theory is good, except, if the impellar was "going bad", yo might still get the boat moving quick before the heating starts.

John

Well here is the final diagnosis--

Bad impeller (2 blades out of 16 remaining on it) caused boat to overheat which in turn caused either the riser to crak or head gasket to blow which in turn led to water in the number 6 and 8 cylinder.

All can be repaired for a minimum of 500 and a maximum of 1000

So anyone in Jax want some gas money to ride this week???????

ouch. must be the headgasket, and that ain't the cheap one. the riser would probably affect all 4 on one side. i hope the head itself is ok.

Here's the kicker, there are two bad cylinders-one on each side!! I can't afford to fix it right now but the problem is making sure that the water in the cylinders is dryed up or else the cylinder wall will rust resulting in the need for a new motor!!! I sprayed some wd-40 into the cylinders via the spark plug holes to keep it wet in there but I will be taking the heads off with my neighbor this weekend to dry it up. This is why your friends boat is the best one!!

not to be the bearer of bad news but depending on how long the gasket was bad you run the risk of possible block damage. I replace an engine in my buddies malibu cause the gasket went out but he kept driving it around and the water actually cut a channel into the block.

Winterize it. The fogging oil will adhere to the cylinder walls and prevent rust buildup. I can't see why this won't work - can any of you guys?

Thats what I was thinking..anyone else agree? That may be the best solution for the time being until I get up some dough.

The best part is having my house for sale and knowing that I am going to make a killing when it sells next month but for right now I am screwed!!

When it rains...it pours..