Max Speed?

[Dolfan0925]

Was wondering how fast my boat should be going. Mid-late 80's 17' Maxim Bowrider, 90hp Mercury outboard. Haven't had it very long, replacing plugs/wires and such. Feel like it should be more powerful. Max speed on flat water with no wind 23mph.

Thoughts?

 

[arks]

Re: Max Speed?

Yeah, 23 seems way too slow for that boat. How did you measure speed? Boat speedos are notoriously inaccurate. A handheld GPS will give you exact speed, but won't account for current flow.

 

[Dolfan0925]

Re: Max Speed?

Just got a fishfinder with GPS. So it was deifinitely 23mph. BARELY makes it to 23mph.

 

[Bob_VT]

Re: Max Speed?

You need to verify if the motor is really hitting on all cylinders and make sure there is a clean and dry hull too.

Is the boat new to you?
Is there waterlogged foam or water in the hull?
Have you checked each cylinder for compression, spark and when were the carbs last rebuilt?

 

[Bondo]

Re: Max Speed?

Max speed on flat water with no wind 23mph.

Ayuh,... At what Rpms,..?? with what prop,..??

 

[steelespike]

Re: Max Speed?

As Bond-o suggests speed without rpm and prop size doesn't mean much except you are slow.
Should easily do 30 to 35 with more possible

 

[26aftcab454]

Re: Max Speed?

the motor should be turning around 5500 RPM at WOT-moving around 35mph+

 

[Dolfan0925]

Re: Max Speed?

I have a nice list of things to figure out. Tach's not working so that'll be on the top of the list.

TY!

 

[QuietRider21]

Re: Max Speed?

i had a 89 maxum 17' with a 3.0 i/o that did 43mph. i also had a 93 bayliner 18' with a merc-force 90 outboard that topped out at around 36..theyre light boats...how many people did you have in the boat?

 

[waterinthefuel]

Re: Max Speed?

Was wondering how fast my boat should be going. Mid-late 80's 17' Maxim Bowrider, 90hp Mercury outboard. Haven't had it very long, replacing plugs/wires and such. Feel like it should be more powerful. Max speed on flat water with no wind 23mph.

Thoughts?

Dude, my 28hp fiberglass boat does 27.5 on a GPS. You are dead dog slow. I have a feeling you might have an engine issue. Did you check the compression? How old is this engine?

 

[Cadwelder]

Re: Max Speed?

I have a nice list of things to figure out. Tach's not working so that'll be on the top of the list.

TY!

Yep for sure fix the tach, I wouldn't run at all without it......by far the most important instrument on your boat.

 

[DaNinja]

Re: Max Speed?

Yep for sure fix the tach, I wouldn't run at all without it......by far the most important instrument on your boat.

I think that's a bit extreme.
By far...really? I'll take oil pressure and a temp guage over a tach.
A good check of the engine, prop and maybe a look to see if Dolfan's boat may be carrying some extra weight (water logged) that he didn't know about.

 

[Lyle29464]

Re: Max Speed?

I think that's a bit extreme.
By far...really? I'll take oil pressure and a temp guage over a tach.
A good check of the engine, prop and maybe a look to see if Dolfan's boat may be carrying some extra weight (water logged) that he didn't know about.

what would be a good temp and oil pressure on that 90?

 

[rickryder]

Re: Max Speed?

Sounds slow to me too.... my 76 14' chrysler trihull with a 55 hp chrysler 2 200 lb guys and a big cooler 2 6 gal fuel tanks 26mph

 

[DaNinja]

Re: Max Speed?

what would be a good temp and oil pressure on that 90?

I don't now... just responding to the importance of the tach as being the most important guage in Dolfan's situation.
If there was gauges that I would put as a must have, it would be temp and oil pressure.
Both have cost me more money than the tach ever did.

 

[Dolfan0925]

Re: Max Speed?

I don't now... just responding to the importance of the tach as being the most important guage in Dolfan's situation.
If there was gauges that I would put as a must have, it would be temp and oil pressure.
Both have cost me more money than the tach ever did.

Ya don't have an oil pressure or temp gauge. Gas gauge doesn't work either. Battery gauge works though!

But only paid $900 for everything so I'm happy it moves at all and doesn't sink.

 

[DaNinja]

Re: Max Speed?

Ya don't have an oil pressure or temp gauge. Gas gauge doesn't work either. Battery gauge works though!

But only paid $900 for everything so I'm happy it moves at all and doesn't sink.

Safe boating!

 

[Joshua Nichols]

Re: Max Speed?

I wonder if ya could get away with sticking one of these things on it just to see what the RPM is.. Cause who wants to blow cash.. I wouldn't say a tach is the most important gauge on a boat.. I don't even think mine is correct..
Throttle control is opening the carbs to WOT correct? Have ya checked?
Having only paid 900 for the rig I bet ya she is water logged and or has gummed up carbs.. :facepalm:

How cute they removed my Ebay link... Ummmm iboats doesn't sell such as I posted...

 

[Cadwelder]

Re: Max Speed?

I think that's a bit extreme.
By far...really? I'll take oil pressure and a temp guage over a tach.
A good check of the engine, prop and maybe a look to see if Dolfan's boat may be carrying some extra weight (water logged) that he didn't know about.

Oil pressure gauge on a 2 stroke outboard?? I may lean to a water pressure gauge over the temp, but still stay with the tach on an outboard as a very important one.