Boat is running awesome

[bent99]

What should my 4.3 18 foot checkmate rev to? I went full throtle yesterday across lake and it pretty much topped out at 3500 rpm. Fun Fun

 

[hystat]

4200-4600 rpm

a few possibilities why you are low:

-tach wrong
-wrong prop pitch
-low power
-throttle linkage not moving full travel

 

[bent99]

I am gonna check throttle travel tonight for sure. Anyway it planes out pretty quick and everything else seems great. I cant believe I waited this long to boat.

 

[bent99]

Whatwould be safe ignition timing with this 4.3 running super unleaded? I think I am at 6 degrees b.t.d.c.

 

[boatin_bob]

Right on....6 BTDC if running 89 or higher

 

[chiefalen]

do a compression test, if good then a vacuum test. What prop pitch ?

 

[bent99]

I foundsome numbers on prop ,they were 14 x 23 . I had boat on lake last night anditis definately taking on water whether it is running or not. If you are not sure where water is coming in at ,what should I change out ?

 

[boatin_bob]

23 is a lot of pitch, if you went down to a 19 your RPM's will come around 800 (200 for each of pitch). You must of had a slow hole shot as well with that prop? A smaller pitch should pop you right up out of the water.

If you can't see where the water is coming in then I would pull the drive off and inspect the drive bellows and the shift cable bellows for rips/leaks.

 

[bent99]

it actually pops out of water pretty fast, but I have never drove another boat so maybe im just notknowing how fast a boat can plane out. Is there something else involved with the shift cable bellows or is it pretty much setup like the ujoint bellow. thanx guys

 

[chiefalen]

somebody put that prop on there. Shouldn't we find out first if there is another reason it is not achieving recommended wot ?

Free tests just takes a little time and the numbers latter if stored will give you a benchmark down the road.

It's your boat do what you want.

Me i would do the tests.

 

[boatin_bob]

Shift bellows is much smaller than the u-joint one and fairly involved to replace. Chief is right (as usual) shouldn't jump to conclusion that the prop is wrong on your boat but in my experience a 23 pitch takes an awful big bite out of the water. If you borrow a smaller pitch one it would be an easy test but of course you need to verify that everything else is working correctly too.