WOT only 2200 RPMs

[Katiejoe2005]

Just got my first I/O. All i had previously were jet boats. It's a 1995 aquatron 3.0 mercruiser alpha one LX. Took it out for the first time. Starts quickly, runs great, idles smooth but I only get 2200 rpm unless that guage is wrong. Doesn't seem to be an engine issue. What could it be. Speedo doesn't work so I am unsure of the speed at that rpm. I'll GPS it tomorrow.

 

[bonzoscott]

Re: WOT only 2200 RPMs

Welcome to iboats! Get your speed reading and respond. The first thing that comes to mind is your boat maybe over propped. How many feet is the boat and approx. weight? Just as a basis, should probably have no larger than 19 pitch. Looking at the back of the prop, get us the numbers inside the hub.

 

[Eric 3.7LX Alpha 1]

Re: WOT only 2200 RPMs

Here's some reading material... a check list to go thru:

Thread: List of possible causes of low WOT
http://forums.iboats.com/mercruiser...ives/list-possible-causes-low-wot-295070.html

 

[Katiejoe2005]

Re: WOT only 2200 RPMs

Welcome to iboats! Get your speed reading and respond. The first thing that comes to mind is your boat maybe over propped. How many feet is the boat and approx. weight? Just as a basis, should probably have no larger than 19 pitch. Looking at the back of the prop, get us the numbers inside the hub.

So today with 7 people aboard at 2200 rpm was GPS 35 mph trimmed about half way up (unsure how much to trim up). It's a 1995 Aquatron 190 3.0 mercruiser LX. It's 18.4 feet long and weighs 2300 lbs. it's a 19 pitch prop. The number on it is 1511-145-19.

 

[Katiejoe2005]

Re: WOT only 2200 RPMs

I looked for the out drive ratio but couldn't find it but the Serial number back there is 0F540529

 

[Bondo]

Re: WOT only 2200 RPMs

So today with 7 people aboard at 2200 rpm was GPS 35 mph trimmed about half way up (unsure how much to trim up). It's a 1995 Aquatron 190 3.0 mercruiser LX. It's 18.4 feet long and weighs 2300 lbs. it's a 19 pitch prop. The number on it is 1511-145-19.

Ayuh,.... 7 persons in an 18' boat, is Overloaded,....

'n yer tach is Off, Way off,... No way that rpms will yield 35 mph,...

 

[Katiejoe2005]

Re: WOT only 2200 RPMs

So after fixing the tach, WOT at 4600 rpm was GPS 37 mph. Trim at the 1/4 mark. I was thinking I should hit 40. With new spark plugs. 3 adults and 2 small children

 

[bonzoscott]

Re: WOT only 2200 RPMs

You're doing good with that RPM and weight. That's about it for a 3.0. I bet it'll do 40 with just two people.