Yamaha 242 Limited S loss of power

[biffdotorg]

One shot of sand is not going to wear an impeller that much. That being said, if it is out of spec now, it doesn't matter how it happened, it needs to be addressed to get rid of cavitation.

Did the mechanic recommend an impeller, wear ring, or both? There is no arguing a measurement. If it's out of spec, it's out of spec and a place to start.

When we used to pull waverunners off a sandbar, or whenever they sat anchored, we always lifted and dropped the stern to pump water through the jet pump to flush out sand and weeds before firing up. We don't really have that option on a 24ft boat. But just pushing it out away from a sandbar or beach would push some water through the pumps and flush loose sand for sure.

Good luck!

 

[TomTom]

I did not take it to the mechanic yet. I want to see how the impeller looks and the wear ring. If it looks bad I know what it is at least. Hitting 7k RPM and only going 12mph is not normal the only thing that comes to my mind what is could be is the impeller and the wear ring.

 

[marshkimbell]

When I first got it in June I took it out with 1550 lbs of passengers and 300 lbs of fuel. The boat had no problem pulling my big butt out of the water and I weigh 250lbs. I took it out about 6-7 more times during June and early July. This past weekend I had 1530 lbs of passengers and 300 lbs of fuel. When they tried to get me up on the board the boat struggled. I tried several riders and we all struggled to get up. The boat just did not have the low end torque it had a month ago. I read several things online regarding jet boat cavitation and loss of low end power due to impeller damage and jet pump blockage. I removed both impeller assemblies and did a visual inspection for damage. Negative on damage.

Any ideas?

I have the same issues. 1500 new impellers and still won’t make it past 6500rpms and only 37mph. Had about 1200 lbs and took forever to plane out. Does it with 8 people or just me and my wife

 

[Neutron]

I have the same issues. 1500 new impellers and still won’t make it past 6500rpms and only 37mph. Had about 1200 lbs and took forever to plane out. Does it with 8 people or just me and my wife

Did you pay $1500 for 2 new impellers? If so you got robbed or i am not charging nearly enough

 

[biffdotorg]

I think this conversation is going in the wrong direction. A worn impeller or wear ring would make the pump cavitate and RPM's would go up with no thrust. Just the opposite of what you guys are experiencing. The only way the impeller and wear ring would cause low RPM's would be if there were something in there between the two holding the engine back.

If you have low RPM's and can't push into the WOT sweetspot, then start at the engine. I don't recommend it as often as other do, but spart plugs and oil level are the easy buttons. Then fuel pressure. In actuality, this is the only time I ever swap spark plugs, is when I experience low RPM's.

good luck