2012 Challenger 180 SP Stutter

[sp_cruiser]

Hi All!

Bought a 2012 Challenger 180 SP a couple of weeks ago. About 225 hours on the boat, supercharger clutch was redone at a dealer around 178 hours. Overall, the boat starts easy, seems to run mostly well.

However - I've noted that when moving from idle to full throttle (or close to it) there is a temporary stutter that almost sounds like a car hitting a rev limiter. Almost seems like lack of air, fuel, or water flow through the intake.

Starting at idle and gradually moving the throttle up doesn't experience it. Top speed is about 45/46, seems to run fine once at full throttle, runs fine at idle, runs fine in the middle if getting there gradually. It's pretty much only noted when taking off quickly (with or without a skier).

I thought it might be bad gas given it hadn't yet been run for the year so I added some injector cleaner and stabil, and have since gone through a full tank of ethanol free premium fuel.

Thanks for the help!

 

[LionOnABeach]

Cavitation in your impeller/pump. Happens to me if I stomp on it towing a tube with people sitting in the back. Bow jumps out of water and after 5k RPMs you can hear the change in engine pitch as revs increase and also change in the vibration/sound coming from the pump. Worn pumps, wear ring, etc can lead to cavitation too.

 

[sp_cruiser]

Cavitation in your impeller/pump. Happens to me if I stomp on it towing a tube with people sitting in the back. Bow jumps out of water and after 5k RPMs you can hear the change in engine pitch as revs increase and also change in the vibration/sound coming from the pump. Worn pumps, wear ring, etc can lead to cavitation too.

Thanks! So when that happens for you - does it also work out of it after a few seconds?

The owner provided both a spare plastic wear ring and a spare metal wear ring, as well as a new impeller. Maybe I should switch those out now? Any experience w/ metal wear rings?

 

[LionOnABeach]

Thanks! So when that happens for you - does it also work out of it after a few seconds?

The owner provided both a spare plastic wear ring and a spare metal wear ring, as well as a new impeller. Maybe I should switch those out now? Any experience w/ metal wear rings?

Yes, maybe a fraction of a second now since I can hear/feel it and adjust throttle accordingly. Or just move bodies around to get a better weight distribution and not slam the throttle as hard (but I do like how it jumps when you mash the gas!)

why did the PO buy spare rings/impeller? Did he know that he would need them? You can always crawl under and take a look at the impeller and ring through the grate to see if there’s excessive wear, scoring, bent impeller blades, etc. anything that would cause turbulence during water flow through the housing.

ideally, with everything up to spec, you should be able to hammer down and not get cavitation, but with anything, there’s always a variable that can throw a wrench in things.
How bad is it? I’d see if you can’t live with it and adjust driving style until the end of your season, then do the repairs and swaps when you’ve got the time in the off-season.

 

[sp_cruiser]

Yes, maybe a fraction of a second now since I can hear/feel it and adjust throttle accordingly. Or just move bodies around to get a better weight distribution and not slam the throttle as hard (but I do like how it jumps when you mash the gas!)

why did the PO buy spare rings/impeller? Did he know that he would need them? You can always crawl under and take a look at the impeller and ring through the grate to see if there’s excessive wear, scoring, bent impeller blades, etc. anything that would cause turbulence during water flow through the housing.

ideally, with everything up to spec, you should be able to hammer down and not get cavitation, but with anything, there’s always a variable that can throw a wrench in things.
How bad is it? I’d see if you can’t live with it and adjust driving style until the end of your season, then do the repairs and swaps when you’ve got the time in the off-season.

PO's statement was that he had them in case of any ingestion caused failures so he could just swap them out quickly. He had paperwork for all major services, so I'm inclined to believe that.

As suggested, I'll likely wait until end of season since it's not too far away and I'm mostly towing kids. However, it does happen even with just me in the boat and no tow. I can also correct for it, but that's not much fun >_> - My main worry was some indication I saw that it could cause larger damage if too bad. I'd say when I throttle it, it lasts for 5 seconds or so before it catches it.

 

[MacSeaDoo]

Sounds like cavitation. Before you go and pull anything, crawl under the boat and look up into the grate down to the back and look at the impeller and wear ring. Take a photo if you can as we can all comment.

Metal wear rings are great but they are unforgiving as if you pick up a rock, it can stop the engine dead or bend/break the impeller.

 

[MacSeaDoo]

My 150 has a bit of cavitation as well and my wear ring and impeller are basically new. I do notice in mine whoever had the pump off last went crazy with the black sealant. I may be able to fix mine permanently by cleaning up those spots because anything that will disrupt flow will contribute to cavitation. If you can feel it though while underway with throttle changes, I would say you should take a look.

 

[MacSeaDoo]

Here is mine...

 

[sp_cruiser]

Here is mine...

It'll be tomorrow before I can get a picture. Nasty weather at the moment.

 

[LionOnABeach]

Here is mine...

Woah! They did go crazy!
A couple of mine. That little wood chip gave me nasty vibrations about 4K RPM. The pliers are in one of those pics. Then I wasn’t paying attention and wrapped a tube rope on it. Had to get towed in to dock. Cut that out and unwrapped it. I’ve been down there more than I should!

 

[MacSeaDoo]

Woah! They did go crazy!
A couple of mine. That little wood chip gave me nasty vibrations about 4K RPM. The pliers are in one of those pics. Then I wasn’t paying attention and wrapped a tube rope on it. Had to get towed in to dock. Cut that out and unwrapped it. I’ve been down there more than I should!

Lol, I pulled in the tow rope last weekend. Luckily I heard the line snap the water and hit the off button right away. It never made it to the impeller. Took some dives to pull it out.

You have to love the boating community as we were drifitng past some houses on the water with me diving while my kids eat Pringles on the boat. One couple noticed and got in there whaler to come out and ask if I need help.

 

[MacSeaDoo]

Also, I need to put an exacto knife on a stick and prune out all of the mess of sealant in there.

It is on my "would like to" do list which seems be almost as big as my "should" list.

 

[LionOnABeach]

Lol, I pulled in the tow rope last weekend. Luckily I heard the line snap the water and hit the off button right away. It never made it to the impeller. Took some dives to pull it out.

You have to love the boating community as we were drifitng past some houses on the water with me diving while my kids eat Pringles on the boat. One couple noticed and got in there whaler to come out and ask if I need help.

Yeah, I started and heard a different sound, then killed it, started again (which in retrospect cinched it tight), then killed it, F! Stayed on shaft but couldn’t pull back out or cut. Pontoon anchored next to us offered to tow us to ramp. Boaters are great !