04 Utopia...cavitation or characteristic?

[JholtSRQ]

Just purchased a clean 2004 Utopia 185 w/Optimax 200 D.I. with 50hrs on engine (scanned/confirmed). Had service shop check over and service before putting in water and everything checked out great. My issue is I don't know if I have a propulsion issue or I just bought the wrong boat for my intentions. First boat by the way. The boat jumps out of the hole quickly planes out just as fast with full throttle, but at mid throttle it loses plane and feels like it is pushing through the water losing speed unless you floor it again to get back on plane. My intention was to have a boat my wife and I use to cruise around and relax on the weekends, not adrenaline runs if you will. 20-25mph would be our cruise spot most likely. Also, while trying to cruise at 20-25mph the exhaust fumes are somewhat overwhelming. I wonder if this is also due to cavitation as the engine is at higher rpms than should be at these speeds while not pushing the boat fast enough to outrun exhaust/fumes.

So, I wonder if there is a propulsion issue that once corrected we will be able to cruise comfortably at lower speeds or if by design these boats are meant to run wide open, characteristically not meant for mid throttle cruising and I should look to maybe sell and find another option.

Have also considered the previous owner could have changed impeller for more top end performance, sacrificing the low end performance.

Impeller looks good, clearence to wear ring and guard vanes seem fine. Doubt the pump has ever had any major work done...no tool marks anyway.

Thoughts?

Thanks!
J.

 

[Tim75]

Just purchased a clean 2004 Utopia 185 w/Optimax 200 D.I. with 50hrs on engine (scanned/confirmed). Had service shop check over and service before putting in water and everything checked out great. My issue is I don't know if I have a propulsion issue or I just bought the wrong boat for my intentions. First boat by the way. The boat jumps out of the hole quickly planes out just as fast with full throttle, but at mid throttle it loses plane and feels like it is pushing through the water losing speed unless you floor it again to get back on plane. My intention was to have a boat my wife and I use to cruise around and relax on the weekends, not adrenaline runs if you will. 20-25mph would be our cruise spot most likely. Also, while trying to cruise at 20-25mph the exhaust fumes are somewhat overwhelming. I wonder if this is also due to cavitation as the engine is at higher rpms than should be at these speeds while not pushing the boat fast enough to outrun exhaust/fumes.

So, I wonder if there is a propulsion issue that once corrected we will be able to cruise comfortably at lower speeds or if by design these boats are meant to run wide open, characteristically not meant for mid throttle cruising and I should look to maybe sell and find another option.

Have also considered the previous owner could have changed impeller for more top end performance, sacrificing the low end performance.

Impeller looks good, clearence to wear ring and guard vanes seem fine. Doubt the pump has ever had any major work done...no tool marks anyway.

Thoughts?

Thanks!
J.

You never gave any info about your engine RPM. Jet boats typically need more rpm than a very similar prop boat. I have a 2000 Challenger 20 with 240 EFI. If I rev to 3800rpm, it takes 300 yards to get on plane with just 2 people on board. I get about 28mph.

My boat planes easily at 6000rpm (same load). At 3500 rpm, it starts to fall off plane. You may be trying to go too slow for the hull to plane. Moving any load forward will help some.

Typical cause of cavitation is an air leak on the suction side of the impeller.

 

[abnwayne]

i have a 2001 utopia 185 with the 200 optimax and it wont stay on plane below 3k rpms. its normal the sweet spot for cruise is around 3800 to 4k rpms

 

[JholtSRQ]

Thanks for the replies fellas. Unfortunately the tach and the speedo are the only two things that do not work on the boat. Based on your comments and conversations I have had with others, the boat is fine...seems I just bought the wrong boat. Probably going to sell it and look into either a center console or a camper if anyone is interested in it. Will post it in FS section soon most likely.

 

[mstubbs007]

You never gave any info about your engine RPM. Jet boats typically need more rpm than a very similar prop boat. I have a 2000 Challenger 20 with 240 EFI. If I rev to 3800rpm, it takes 300 yards to get on plane with just 2 people on board. I get about 28mph.

My boat planes easily at 6000rpm (same load). At 3500 rpm, it starts to fall off plane. You may be trying to go too slow for the hull to plane. Moving any load forward will help some.

Typical cause of cavitation is an air leak on the suction side of the impeller.

Try a set of trim tabs should help for sure Smart Tabs SX Series Trim Tabs sx9510-60. This is what I put on my 2005 Sea Doo Utopia 185 with Optimax 200 and she gets on plane with no problems at lower speeds and ride has smoothed out since I installed the Smart Tabs.

 

[JholtSRQ]

Try a set of trim tabs should help for sure Smart Tabs SX Series Trim Tabs sx9510-60. This is what I put on my 2005 Sea Doo Utopia 185 with Optimax 200 and she gets on plane with no problems at lower speeds and ride has smoothed out since I installed the Smart Tabs.

I might try that. Thanks!

 

[Murph_13]

I have a 2002 Utopia 185 and agree with abnwayne, the "sweet spot" for cruising is 3800 - 4k rpm which puts me at 25 - 30 mph dependent on water conditions. These boats can be great for cruising around and once you get acclimated to the boat and find that "sweet spot" for cruising I think you will really enjoy the boat.

I would try to get the tachometer working so you know your engine speed and can learn where your "sweet spot" for cruising is (assume you'll find it to be the 3800-4k rpm range). If you are unable to resolve the issue with the tachometer, maybe install an inexpensive inductive pick up tach/hour meter that you can mount near the dash/helm to display your engine speed.

If the sound deadener on the inside of the engine covers is in poor shape, you may want to replace it to keep engine noise down while cruising. I replaced mine years ago with Dynamat Xtreme on the top and sides and then added the Dynamat Hoodliner to the top and it is very quiet inside the boat at higher engine speeds. It made a huge improvement.