High RPM, can’t get over 10mph...Opinions please

[AAron21]

2nd time on the water and not very good. Can not get over 10mph and boat sounds horrible past 6k rpm. As if impeller is contacting wear ring or some other friction. No codes, engine sounds good in Neutral and revving throttle to 6k. Removed impeller and wear ring and hopefully this is the issue. I do not notice any swelling of the wear ring but obvious signs of simpeller contact. Plan is to order new impeller and wear ring. My concern is the wear to the housing behind the wear ring. Tach shows only 29 hours, so it’s obvious previous owner did some damage on a sandbar. Should all of this be replaced? Is there a way to have both these units resurfaced to save for later? Thanks in advance, I appreciate everyone’s input. Super helpful for a first time jet boat owner

 

[Dave burke]

Clean out ports are good? 10 mph is really slow

 

[tdonoughue]

So, a couple of observations and questions...
1) You said this was your 2nd time out. How was the 1st time? Any issues like this? What was your top speed then?
2) I see the evidence of contact, but that is not much and certainly nothing that should keep you at 10mph.
3) Leading edge of your impeller looks a little chopped up, but I have seen worse. Take a file to that and clean it up and you probably have more life out of it.
4) On my 2nd time out, I had a similar experience and found out I had not put the plugs in properly. Were those all locked down as they should be?
5) Sounds like a cavitation problem--like can happen when something is stuck in the pump or on the grates. Any foreign matter around there anywhere when you pulled the pump?

Also, I am only over in The Woodlands. If need be I'm sure I could take a little road trip...

 

[Scottintexas]

I graduated from kingwood! Lived in forest cove,

I also agree, seen much worse that didn't cause problems ,

I try another test on the water before you replace anything

Could have been improperly sealed cleanout or debris in the pump that fell out when you took the boat out of the water


.

 

[AAron21]

So, a couple of observations and questions...
1) You said this was your 2nd time out. How was the 1st time? Any issues like this? What was your top speed then?
2) I see the evidence of contact, but that is not much and certainly nothing that should keep you at 10mph.
3) Leading edge of your impeller looks a little chopped up, but I have seen worse. Take a file to that and clean it up and you probably have more life out of it.
4) On my 2nd time out, I had a similar experience and found out I had not put the plugs in properly. Were those all locked down as they should be?
5) Sounds like a cavitation problem--like can happen when something is stuck in the pump or on the grates. Any foreign matter around there anywhere when you pulled the pump?

Also, I am only over in The Woodlands. If need be I'm sure I could take a little road trip...

So, a couple of observations and questions...
1) You said this was your 2nd time out. How was the 1st time? Any issues like this? What was your top speed then?
2) I see the evidence of contact, but that is not much and certainly nothing that should keep you at 10mph.
3) Leading edge of your impeller looks a little chopped up, but I have seen worse. Take a file to that and clean it up and you probably have more life out of it.
4) On my 2nd time out, I had a similar experience and found out I had not put the plugs in properly. Were those all locked down as they should be?
5) Sounds like a cavitation problem--like can happen when something is stuck in the pump or on the grates. Any foreign matter around there anywhere when you pulled the pump?

Also, I am only over in The Woodlands. If need be I'm sure I could take a little road trip...

1st time was rough. I was having communication errors, but I was able to plain and speedometer was reading 43 mph consistently. Problem was I couldn’t read rpms. Changed all the terminal leads and tendered the batteries. Comm error fixed. Took it out yesterday hoping all the bugs were worked out and ran into the possible cavitation issue. The plug makes sense as it was seized and I removed it with a jack. Cleaned up all the sediment in the port and on the plug. Tried the old again before using the new yesterday. I will replace the plug and give it another try. I appreciate the opinions on the impeller and wear ring. I’ll update after the next run. Thanks again

 

[OrangeTJ]

Almost has to be cavitation or an obstruction in the flow path. If it isn't the plugs being seated improperly (which I had that problem my first time out), perhaps there is an issue with your buckets falling into the jet stream.

 

[tdonoughue]

If you had good runs the first time (43 mph sounds about right, a little slow maybe), then I bet you sucked up something. May have even fallen out as you pulled the pumps (that happens & people don't notice).

I would re-assemble and try again. But I would file off those impellers first, while you have them out. Takes 10 min and may get you another 3-4 mph.

 

[AAron21]

Thank you all for the help. It was the jet port plug. I had hoped that after cleaning the old one, I could hang on to the new for awhile longer. Lesson learned. I think during the winter I’ll invest in SS housing and wear ring along with a SS impeller. Hope all of you had a safe and happy Memorial Day. Take care