250 Suzuki not reaching speeds expected

[isakeith]

I purchased a new 730 bar crusher hard top with a 250 Suzuki outboard. ( the 300block )The prop is a stainless steel Suzuki prop 3x16x18 5R.The motor is only revving out to 2250 -2500 max achieving about 55km/hr . the dealership have tried different prop sizes but actually went slower .

Tried changing the fuel line as it looked like it was sucking in on one of the bends. some short time improvements but back down again now. At one time on the water cruising along the boat actually took off to what i believed to be performing as it should, but only lasted for about 2 mins . any ideas as the same boat with a 225 motor is pulling over 75km/hr. the motor has done approx 25 hrs . any ideas?

[Skusto]

Take it back to the dealer and make them fix it, you brought a new boat with warranty for this reason.

Do not touch anything as it will give them warrant to not fix stuff!

If dealer won't help then ring Barcrusher them selves as I'm sure they could point you in another direction or get the dealer to fix if it does relate to fuel lines.

Or try another Suzuki dealer.

Either way there is something not right at all with the motor, whether it be the motor itself or a kinked fuel line and starving for fuel like you say.


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[inveratta]

Does the dealer think there is something not quite right? Its new after all....if the dealer is reluctant to take it further ..I would be asking Suzuki directly to send someone down for a motor and fitment test... I reckon the last thing to do at this stage is to alter the set up yourself...

[fishing111]

Who's the dealer, and how long has it been like that? Surely a dealer wouldn't let a motor go out only achieving 2500 rpm. It's not up to you to find the answer if that is the case. Something odd here?

[DaveR]

Those numbers don't add up for me, it shouldn't get anywhere near 55km/h if it can't get past 2500rpm. To hit 55 kays with your prop and gear ratio, you'd need to be doing over 4000rpm. Obviously still means something isn't right, WOT is 5500rpm+ on this engine. Your theoretical top speed for the prop/engine combo is at least 75km/h at the bottom of the WOT range and over 80km/h if she gets near 6 grand, give or take a small amount depending on slip etc.

Given it snapped out of it and performed correctly (briefly), I'd skip the usual engine height/prop issues and look into a potential fuel issue or something else with the engine. Could be a number of things, you should get Suzuki/BC involved ASAP, I'm surprised you made it to 25 hours with an issue like this. We use the same Suzukis (300hp block) on the Marine Rescue cats, they are a very strong engine. Hopefully you get yours sorted soon, the dealer should be bending over backwards, given what a 730 BC is worth, it should have been water tested and delivered perfect.

[inveratta]

been thinking about this...without knowing the set up..is it possible that the fuel tank vents are blocked so the motor is pulling against a vacuum..??

[scottar]

Anything is possible. Wouldn't be the first new tin boat that had ally swarf in the tank causing issues either as another thing to investigate. I do agree with the sentiment of at least giving the dealer the chance to sort it. If no joy there, next call would be Suzuki. If still no joy I would look at running on a tote tank to isolate the engine from the boat as a start.