help - lost top end
 

Hello All,

I have an '04 25 outlaw with the 425hp. It has a 23P balanced prop and captains call exhuast. The boat has 180 fairly easy hours on her. Last summer it was doing 66-67mph on gps at 5200rpms. This summer I am getting about 62mph at 5000rpm's.
It idles fantastically at 700 and cruises at 3800 45mph dead on with 2 people 1/2 tank of gas.

So, what happened? I changed my water/fuel seperator and in-line fuel filter, which by the way I got screwed for $52.
I am not sure of the next step, the prop looks great and I am looking for advice. Oil is changed every 20 hours.

Cheers,
Scot

Change your plugs...

Was the temp and humidity the same? Heat will cause loss of speed

you also may want to check the compression to be safe.

At the last dealer meeting every boat was about 4 to 5 mph slower in the Florida heat. Up here they ran fine.

Interesting, I am in New Hampshire and our humidity over the last week has been horrendous and temps around 90.

These are platinum $$$ plugs, how often would you change them?

Cheers

If they are the original plugs I'd probably say your due...

Motors vary wildly due to heat. My boat runs up to 8mph difference in 115 degrees versus 80 degrees.

My bet is the heat and water temp.

The boat has a closed system. So, its not water temp. Heat and a mixture of moisture makes sense, though.

I have done the in-line fuel filter and water seperator with no luck. I am going to do the plugs this weekend and will update all.

Relaxalot, be happy your boat or yourself runs at all at 115 degrees. I though you had to get to New Dehli, India to see those temps.

It might have something to due with all this crappy gas we have been getting for awhile. I had to go up a jet size in my carb this year must be that ethanol or whatever else the gas companies are skimping on. And this year if my boat sits for 3 weeks 9 out of 10 times the front float is stuck closed.