Never ending performance problems...

[merik]

Hi

I started this thread (link below) last year about performance problems with my 05 Challenger 180 SCIC:

http://www.seadooforum.com/showthread.php?t=14042

Time has passed since that and several parts have been replaced. Performance has improved greatly but I'm still not completely satisfied.

Please look at this youtube-video: http://www.youtube.com/watch?v=wv7EmnREuZY

You will see me go WOT from about 3000 rpm and the engine will instantly reach 8000 rpm. This is only possible when I'm the only passenger and the fuel tank is below half. If I put any extra weight in the boat I have to be very gentle on the throttle, otherwise it will just bounce of the rev. limiter. After I reach adequate speed you will see me reduce to 1/2 throttle and the engine will do about 7000 rpm. At 3/4 throttle I'm back at 8000 rpm.

This is what I have done so far:

Replaced wear ring and impeller
Replaced the neoprene seal between pump housing and hull.
Removed and polished the drive shaft.
Replaced the drive shaft carbon seal.

Is this really the way the boat should behave or can I expect better performance? If that is the case, what more can I do? I've been thinking about replacing and resealing the pump support as the next step but that’s a lot of work and I want to make sure that it’s the only thing left to do.

Best regards
Erik
Sweden

 

[Bills86e]

Could be prop is very under pitched. You might as well just be cavitating. Any
idea of its speed ?

 

[merik]

I have not checked the impeller pitch, but I did replace it with the stock OEM part. Top speed is 42 knots (48mph) at 8000+ rpm with just me and a half tank of fuel on-board. It feels like the boat has more to give since I reach 8000 rpm at just 3/4 throttle.

 

[Chester]

Try re-sealing the ride plate. Also, check for cracks in it.

Chester

 

[merik]

Chester, thanks for your advice. As far I can see, there are no cracks. Do you have experience from resealing ride plates? The procedure is not covered in the shop manual. I know there are 6 nuts to undo from inside the hull, but then I'm lost?

But before I do any more work I need to know that I really have a problem. I know it sounds funny but the problem is that I have nothing to compare with, hence I don't know what to expect from my boat when it comes to performance. I always thought that bouncing of the rpm limiter under normal everyday use was a sign of malfunction. But I've heard from other forum members (thanks seadoosnipe ) thats it's very common for jetboats to do that. It would be really helpful if another C180 owner could describe how his or her boat behaves under different loads. When looking at videos online I get the feeling that other similar jet boats grabs the water much quicker and accelerates better than mine. Of course I want my boat to perform 100%, but if someone with experience of these Challenger models tells me it’s running just the way it should at the moment, I’ll accept it and have peace of mind again.

/Erik

 

[charlieenz]

Hi From New Zealand - I've recently purchased a 2007 C180 and its close to max at just over half throttle as well. I think the power curve is very bottom ended and the last bit of throttle doesn't give a hell of a lot more go. mines got the digital rev counter so hard to say how steady it really is. Your boat sounds on the video fairly similar to mine. What I've found is water conditions make a huge difference to the ride and with a bit of chop it can feel like a continual top end surge but probably just the nature of a jet handling a constantly changing water flow. On calm water things are way smoother. Speed is excellent and better than i'm getting! cheers-
charlie

 

[merik]

Hi Charlie, thanks for your input. Nice to hear that my top speed is excellent.

I found this very interesting thread:
http://www.seadooforum.com/showthread.php?t=23840

Perhaps a new performance impeller will improve my hole shot. It's definitely worth a try. Now, if I can just get all the snow to melt.

Erik

 

[impalaman]

I think your motor never misses a beat.I think also it's a little torque sensitive in that it really does not have alot of bottom end and that all the power is up top
I think some of us are more concerned with the top speed of the craft than bruttle acceleration.
I say to my boating friends:do you want a Ferrari that will go 200 or a tractor that will pull your arms off at 30.One's for skiing and the other top speed.
It looks like your tach is a little flakey too(no offense),but I think the red line is lower than that,but I might be wrong,but 8k?


Greg in Montreal

 

[merik]

New season...new problems. This spring I replaced the stock impeller for a Solas SRX-CD 14/17 in hope of improving my hole shot. I'm sad to say that it actually made things worse. Going WOT from idle speed means bouncing of the rev. limiter even if I'm alone in the boat. With three people onboard I'm basically getting nowhere unless I ease of the throttle. Top speed is the same as before though.

Made a short video today. You can hear the engine hitting the rev limiter several times before hooking up.
http://www.youtube.com/watch?v=y6U6W1FZk6w

I'm reaching new levels of disappointment. Had this boat for three seasons now and never got it running properly. I'll guess next year’s project will be to reseal the ride plate and pump support. If that doesn’t work I'm going back to propellers again.

Erik