Just wanna drills holes and let it sink!!!!!!!!!

1973240SRV

1973240SRV

New Member
Aug 4, 2011
46
LAKE ONTARIO,NIAGARA RIVER
Boat Info
1999 270 sundancer
named all hail plankton
Engines
454 multiport injected w/bravoIII
I cant take it any more 3 shops no 1 can fix it.It wont start and even when it does it runs like crap timming chain ok.I did find some water in fuel AGAIN thank u ethanol.I dropped yet another shop this guy swears he can fix it he says the new fuel eats old pump diaphrams also unless fuel tank is all the way full or emty and treatment kept up HOURLY ethnl pulls water in2 tank.Ive spent so much $ on this is it just the ford mercruisers are junk or am i just cursed
Im at witts end:smt100:smt100:smt100:smt100:smt100
 
Before you do anything else verify that the engine is not toast.

Check the compression on all the cylinders and they should ALL be within 10% of each other. I won't tell you how many times I've helped a friend troubleshoot a motor focusing on a fuel problem only to find out many dollars later that a piston was blown or the rings had seized up and they now had an expensive paperweight. Water in the fuel makes the engine run lean and hot and can burn rings and pistons.

If that is OK ascertain that you have spark. Pull a wire and short it with a screwdriver against the block. Is there a spark?

If that is OK hook a small fuel tank directly to the engine and ascertain if there is a fuel problem or not.

These are ez things to do. Not sure what problem your shops are having. Also what is the year and model Mercruiser engine?

Another thought is that there are some electronics in the distributor that tend to go bad (rust-corrode) that can kill an engine as well. If you have the Thunderbolt ignition they tend to corrode and the engine can go from running to dead from one start to the next. If you have no spark replace the Cap, rotor and electronics inside the distributor. (NOT the expensive module usually mounted on the riser)

Good luck. Troubleshooting an engine is easy if you follow the steps: You need compression, spark and gas and she should run.

doug
 
engine is a 1975 ford mercruiser 233hp 351 cubic inch got comp got spark got fuel hense the issue distrib is a prestolite points removed and a pentronix ignitr installed which when it ran right gave boat almost 5mph more i hope this last guy can fix it and i have read about the new gas disolving carb and pump parts in older engines and also having worked at marinas back in the days be4 ethnl fords were not known for being best engines in the marine world
bad as mercruiser worse as omc
 
Is the boat leaving the shops in good running condition, only then returning to a no start or poor running state? If so, then I would lean toward a fuel problem. But like stated above, without knowing the condition of the engine mechanically, its hard to say where to go next. Not only would I do a compression test, but I would also like to see the results of a cylinder leak-down test. These two tests will tell you is the pistons, rings, cylinders, valves, head gasket and cam timing are in order. Next, what do the spark plugs tell us about whats going on in the cylinders? Lean, rich, water, oil fouling etc. This can point you to a system wide issue or something that's effecting 1 or a few cylinders. Once the engine is found to be mechanically sound, then move on to ignition. are the wires in the correct firing order, is the coil output sufficient. After that, move to the fuel system. Sometimes, the easiest way to determine whats wrong, is to find out whats right!

Ethanol fuel does have a higher moisture absorption rate then non-ethanol fuel, but were not talking quarts of water in a couple of months. Large quantities of water would have to come from the fuel source, not from running ethanol. The worst part of ethanol is what it does to rubber and plastic fuel components. With the age of you boat, I would suggest having the entire fuel system replaced with modern components that are made of materials that are not susceptible to the ethanol. That may include new tanks, but certainly all fuel hoses, fuel pumps and all internal carburetor parts.

Have any of the mechanics capture the contents of the fuel/water separator filters? Whats it look like when left to settle in a glass jar?

Hope some of this may help.
 
ITs fine most times till load is on it which i beg these guys to water test but they never do.spark plugs look great nice evn light tan on all 8 have good compres good spark.i did put a newer alumn tank in when i got boat.im GESN the fuel pump and carb are orig from 1975. guy says he is gonna drain tank rebuild carb and pump and see what happens
 
1973240SRV said:
ITs fine most times till load is on it which i beg these guys to water test but they never do.spark plugs look great nice evn light tan on all 8 have good compres good spark.i did put a newer alumn tank in when i got boat.im GESN the fuel pump and carb are orig from 1975. guy says he is gonna drain tank rebuild carb and pump and see what happens
Click to expand...

Ok, that is some good info. So it runs fine until under load. Try to describe how it act under load. Does is just not wind up in RPM's likes its struggling? Can you tell if the engine is missing under load.

Missing under load is going to be fuel or secondary ignition.

Not winding up could be anything from a restricted exhaust to wrong prop and fuel delivery and ignition timing in the middle.
If its plugged exhaust, a vacuum gauge on the intake manifold will help pin point this.
Fuel delivery could be a restricted/deteriorated hose starving pump or carb or weak fuel pump. A fuel gauge in-line right at the carb will show low pressure. But for a mechanical fuel pump on a carb, I like to do a volume test in addition to pressure, as volume is more important.
Ignition timing thats not advancing will take the balz out of any engine.
Hopefully someone on here can give you an idea of what dia and pitch prop is close to what you should have. Too much dia and it hard to spin and takes a lots of power. Too much pitch and the hole-shot is slow.

Its going to take a sea trial by the tech with some diagnostic gear hooked up.
 
ran great last year same set up.i had an overheat early this year year found alot of 1975 crap in manifolds i cleaned out.was breaking up midrange rpm.wot is around 4500-4800
at 5000 lbs and 233hp its not an animal out of hole. as far as a tech an seatrial $$$$$$$$$$$$$$ which im short on 1 guy wanted $250 just to go out.b4 over heat when i could get it to evn start when i got past that breakup ran good almost 40mph
 
I'll be honest, I'm kinda lost here.

Overheat? Did but now fixed? What got fixed? What was broke?

Now, as I understand it, the present symptom is that the boat starts fine then hiccups (misses) at midrange then catches up and goes balls out 40mph?

You need to state with precision exactly what that engine is doing now and what was corrected in the past.
 
40MPH would be screaming for a 240 with a 233
my 78 240 with 280hp doesn't get near that speed.
 
Sounds like a carb issue to me if your starting fine and idling fine your air fuel mixture sounds good then yougyou give more fuel in return sucking more air, probably more air then fuel (bad seal between carb and intake manifold) then your seconderies open up and dump more fuel and a little more air making the ratio right again. When you over heated (depending on how hot) you could have damaged gaskets. I would start looking for an air leak (bad gasket) even in age gaskets get brittle crack dry out ect. If not done recently I would rebuild or replace carb and again look for vacuum/air leeks
 
when i first got it running the miss started and it was overheating not real bad but enough to cause concern.I put muffs on and it didnt seem like enough water comn out so i took manifolds risers and thermo housing off. what i found was alot of built up rust in manifolds and a some in risers manifolds probly 1/2 full.cleaned out everything evn pulled a couple freeze plugs to if block was clogged no clog in block new thermo all new gaskets.i got it running after that but it ran so bad i cant tell if overheat prob is fixed or not.also if this helps its a 2bbl carb and from what some are sayn 40 is to fast for that boat my speedo may be wrong.oil is clean plugs are clean wires are 2 years old i change water sep filter 2 times a year
 
I'm still sticking with vacuum/air leak. For just a couple of dollhairs pull the carb and replace gasket.
 
If there is a vacuum leak, a couple of well placed spritz from a can of carb cleaner will confirm. But keep in mind, a manifold vacuum leak is present at all engine RPM's and will have the most negative effect at idle. It would have to be be one heck of a gasket leak, like the gasket completely gone, to effrect it off idle. At that point, the engine wouldnt hardly idle without backing the idle mixture screws all the way out and turning the idle speed set screw way up.
 
You may have a hairline crack in the intake manifold which is allowing water to get into the engine. The intake manifolds corrode like the exhaust manifolds but get overlooked. Will cause some odd symptoms.
 
Did you check the spark advance. If the spark is not advancing you would overheat and get some misfiring happening. Just a thought.
 
distrib is advancing.the mechanic just called me he is leaning more and more to fuel and pump issue he got to start with fresh fuel in a 5 gal can.still not running right but it started.ill know more buy thursday
 
Not to beat a dead horse, but is the timing correct and verified without using the harmonic balancer. I know that Fords will have the harmonic balancer shift and so the markings do not always correspond with the crank.
 
I had a Ford OMC in a Cris Craft of mine. Had an acute onset of back firing through the carb about 1/4 to 1/2 throttle, not allowing it to come up to plane. I rebuilt the carb, replaced the fuel pump, already had new cap, rotor, wires and plugs. Long story shot it was the coil, it was over heating.
I read in a blog here somewhere that someone had ignition issues and the found the barings in the shaft of the distributor were worn.

I had another boat that I bought know it had a progressively worsening running rich problem. Eventually to the point it would down right flood over the carb, as in fill the carb and run out the top. Two different mechs rebuilt the carb two times, a third said the bottom half of the carb was rotting, so he built two out of one. When I got it I rebuilt the carb along with dipped it in cleaner JUST TO BE SURE it was done right. I tested the fuel pressure time and time again looking for LOW fuel pressure and I always had enough. So while trying to think outside the box...... I put my finger on the needle (of the the needle and seat) while turning over the engine.... it shot gas all over.. The mechanical fuel pump was building almost 15lbs of pressure (supposed to be around 4lbs)

I know none of this applies directly to your issue but I thought it may help get the wheels turning..

OH... and my 2 cents. I'm going with a fuel air mixture issue. Most likely deep than the carb, like intake or head issue. Good luck.
 
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