www.iFourWinns.com

Hi everyone. First post.
We recently bought a 1988 205 Sundowner with the 205HP V6, it has a professionally rebuilt 4 bbl (carbhttp://flyingfishcarburetors.com/) that was put on as part of the purchase and the problem was there before the carb change. We purchased from a very reputable former Four Winns dealer boat dealer who has been very responsive.
But we are still having 1 major problem. This is my 3rd Four Winns, previously had 1988 180 Horizon V6 and 1989 225 Sundowner V8.
The problem is that when doing about 30 mph and I rapidly push for full throttle the engine bogs down and almost stalls out. This does not happen if you slowly increase the throttle. From a very slow speed if you try for a quick acceleration you might get a momentary lag and then the boat jumps up and takes off with no other issues.
Any suggestions as to the reason for the bog problem. Help!
Thanks

If the problem was there before the carb rebuild, then there are a number of things that can cause this...
ignition....
bad points/condenser, dwell not adjusted properly, timing not adjusted properly, centrifugal advance in the distributor not allowing full timing advance at the specified rpm
weak coil, plug wires with too much resistance, defective plug(s)

fuel....
clogged fuel filter, obstructed fuel vent, corroded anti siphon valve, clogged pick up in the tank, weak mechanical fuel pump
exhaust....restricted exhaust (flappers melted from previous overheat blocking Y pipe)

Prop...over propped (too much pitch) my boat with the same power package, did not perform well with a 14.5x19 prop but performs better with a 15x17. You can even go to a 15.5x15 but that might allow it to exceed the max rpm (4600-4800 is the spec).

_________________
88 Four Winns 200 Horizon
4.3 OMC Cobra-4bbl
2002 Walker Bay 10/2012 Suzuki 2.5
2008 Walker Bay 8

1998 Jeep Grand Cherokee 4.0/Selectrac
2007 Jeep Grand Cherokee 5.7 Hemi/Quadradrive II

LouC,
Thanks for the reply. We will have these things checked out. Some have already been done but the obstructed fuel vent, corroded anti siphon valve, clogged pick up in the tank, weak mechanical fuel pump
exhaust....restricted exhaust (flappers melted from previous overheat blocking Y pipe) do need to be checked.

What carb is on it, the OE Rochester Quadrajet?
From what you are saying, I'd be looking at the ignition system first.
Does it have the OE Prestolite points distributor? Or was it changed to an electronic unit?
The points distributor has a mechanical advance unit below the points plate. It is just a set of weights and springs, centrifugal force makes the weights move outward and that advances the timing to the proper level at a specified RPM. Sometimes because of a lack of knowledge of these older systems the wick in the dist shaft never gets lubed with a few drops of oil and then the weights get rusted up and do not move.
Point gap on this model is .019, dwell is 37-41 degrees, timing at idle speed is 6*BTDC. To check total timing advance you need to be able to run the boat in neutral in the water, at approximately 3200 rpm. This has to be done in the water because you really can't run it at 3200 rpm on the water hose. When it gets to that rpm, the dist should have advanced the timing an additional 12* for a total of 18*. You can use something called an advance timing light to do this. You dial in the degrees of advance, start the engine with the light hooked up (to battery and #1 spark plug) and then point it at the timing mark while someone runs it at 3200 rpm on the tach. If you set the timing light dial at 18* then the timing mark should be right at the same point (6*) you had set it at idle. This sounds complicated if you are not used to older vehicles that had points and mechanical/vaccum advance distributors but its really not. Once the ignition system is set up right then look at the other causes. Older boats often have fuel system problems because of moisture and corrosion.

_________________
88 Four Winns 200 Horizon
4.3 OMC Cobra-4bbl
2002 Walker Bay 10/2012 Suzuki 2.5
2008 Walker Bay 8

1998 Jeep Grand Cherokee 4.0/Selectrac
2007 Jeep Grand Cherokee 5.7 Hemi/Quadradrive II

Seems that the boat is starting to smooth out. 2nd time out no issues with the severe bogging. I talked with the dealer and he and I agreed that I will watch it and if it happens again hthey will bring it in t look it over again.
BTW it was a Rochester Carb and rebuilt by flyingfishcarburators.com they did a great job on the rebuild. Came all adjusted etc.