Loss of speed and another Q

[MercruiserMan]

Hello...I am a newbie to this site but so far I like it...Lotsa info.

My delima:

2005 Four Winns Horizon 180 LE, 4.3L V6. Carb'd.

I used to be able to get 49mph with just me in the boat and normal amount of fuel and gear. With other people in there (4) I could hit 45-46mph.

This year, with 2 people in the boat and normal amount of gear and fuel, I can't hit 45mph. Approx the same with just me in it.

Any idea what could cause this?
-Throttle has full travel
-RPM's are 4700
-It has new plugs
-Fuel filter changed end of last season
-prop in good shape
-clean hull


2nd question:

After a day boating when I pull the plug, I get a lot of water draining out the back. I never took any over the front or sides. Any suggestions where this water is coming from?

I looked the other day while running at 25mph and it seems to be dripping from the bottom of the engine into the bilge.

-The leg was off last year at the dealer.


Thx for any suggestions.

Chad

 

[Don S]

Re: Loss of speed and another Q

-RPM's are 7500

What is it really??????

 

[MercruiserMan]

Re: Loss of speed and another Q

Opps..it edited now to 4700 RPM

 

[180shabah]

Re: Loss of speed and another Q

What was WOT last year?

Now, you need to find the source of the water dripping off of the bottom of the engine.

 

[Haut Medoc]

Re: Loss of speed and another Q

What was WOT last year?

Now, you need to find the source of the water dripping off of the bottom of the engine.

If it is leaking in the back, I would pull the drive to make sure there is no water in the bellows.....

 

[gdombroski]

Re: Loss of speed and another Q

I ahd two things besides for the shift bellows. The Power Steering Cooler is on the back of mine and came apart at the seams. Had it resoldered as very expensive and the other was the exhaust hose off the riser developed a leak.

 

[MercruiserMan]

Re: Loss of speed and another Q

I have a hunch on 2 things..One is the thermostat housing could be leaking and 2--a loose line or hose...When they pull the bellows..see if there is any water in there.

As for the speed..If the timing was retarded, would it cause loss os speed/RPM?

 

[180shabah]

Re: Loss of speed and another Q

As for the speed..If the timing was retarded, would it cause loss os speed/RPM?

yup

 

[MercruiserMan]

Re: Loss of speed and another Q

Is there anything special besides a timing gun required to adjust the timing on this engine?

Cheers

 

[Haut Medoc]

Re: Loss of speed and another Q

Merc or Volvo.......​

 

[MercruiserMan]

Re: Loss of speed and another Q

Its a Mercruiser 4.3l V6 Carb'd

Thx

 

[180shabah]

Re: Loss of speed and another Q

By 2005 they were all TBV(somebody will correct me if I'm wrong), which means you will need to use a jumper to put the system base timing mode then you can use the timing light.

 

[Daddy5295]

Re: Loss of speed and another Q

For timing you will need to put it base timing mode. There is a purple wire with a white stripe on it. Mine sits on top towards front of motor on my 4.3 merc. 05' Chaparral. You need a small piece of wire connect it to the purple/white wire and then ground it to the block, I did it using vise grips to a bolt head. This will put you in btm, remember to disconnect it before using.

 

[Daddy5295]

Re: Loss of speed and another Q

btw the purple/white wire on mine had a rubber plug in the end of it, it is not attached to anything and has a bullet connector on the end.

 

[Don S]

Re: Loss of speed and another Q

First off, if you haven't messed with the distributor, I seriously doubt the timing is off. The easy things are seldom your problem.
The fact that you are getting the same rpm, just different speeds makes me think you might be having a speedometer issue. Please say you aren't using the dash speedometer to read your speed.

 

[MercruiserMan]

Re: Loss of speed and another Q

Yes the timing has been adjusted to try and rectify another issue I am having(dieseling).
But I cannot remember the rpm last year but I think it was higher---not sure though..I had no reason to remember it or document it cause it all seemed normal. But this year I am not going as fast.

And yes I have been using the speedo as a guestimate, but mostly GPS.

 

[Don S]

Re: Loss of speed and another Q

It's really going to take rpm and REAL speed readings. GPS works, the boats speedometer is useless. A small piece of grass can change the speed.
Go back and reset the timing to book specs, and put it in base timing per the manual. Also adjust the carbs idle mixture while in base timing mode.
Your dieseling was probably due to idle speed or not allowing to idle before shutdown. Seldom is a TBV timing issue the cause of dieseling.
Do you have the OEM manuals for your particular engine and drive????

 

[whywhyzed]

Re: Loss of speed and another Q

inspect and clean the intake flame arrester.

find that water leak (via a cooling system pressure test)- it will get worse before it gets better. could be a core plug on the back of the block or just a hose that rubbed through

 

[MercruiserMan]

Re: Loss of speed and another Q

I was out yesterday and I measured my speed (GPS) with 4 people and a dog aboard and it was 42mph with 4150 rpm. So I think I am not turning enough RPM?

Where should I go from here?

 

[Don S]

Re: Loss of speed and another Q

Have you tried adjusting the trim? And I don't mean by where the gauge is pointing if that is what you are doing.
Try trimming up some. If the rpm and speed both goes up,then you were trimmed down to far. When the rpm starts going up and the speed down, that is when you are trimmed up to much and need to trim down a bit.
When you are trimmed down to much, you will have low speed and rpm simply because too much boat is in the water and you are plowing thru the water, not planing on top of it.