another impeller survey

[ar240owner's Wife]

Yes in my old boat it made a huge diferance in pulling power !!!! Ask @ar240owner's Wife !!

Made a huge difference Bobbie!

 

[swatski]

Made a huge difference Bobbie!

@ar240owner's Wife Are you guys taking about your new or the old boat? Your old boat was an AR210, right?

 

[swatski]

What I would really be super curious about is how the new style OEM impellers would work in a MR-1 HO boat!
If I had a MR-1 HO boat, that would be my first mod. I mean experiment .

 

[ar240owner's Wife]

@ar240owner's Wife Are you guys taking about your new or the old boat? Your old boat was an AR210, right?

Correct! Haven't got them on new boat yet. It's on the "list"

 

[Ronnie]

What was the shape of you OEM impellers when you swapped them? Were you changing them to experiment or because of poor performance?

My stock impellers were and still are in great shape.

I only switched them out because I was after better performance generally. No experimenting here, no time, if the solas didn't perform at least as well as stock I would switch back to stock but that's the only reason I'd go through the effort again.

 

[jcyamaharider]

I am with @ar240owner , I think you really don't see huge improvement until pack the boat full of ballast.

 

[Speedling]

I had pretty messed up impellers on my boat which caused me to buy new solas 14/20 impellers instead of refurbish the oem. I would love to see a side by side of the old oem like mine vs the new.

 

[swatski]

I noticed that the Solas props don't cavitate as much as the stock ones did when moving the throttles from idle to WOT quickly. That is, the Solas feel and sound like they are pushing water/ hooking up faster but but for the cost, down time and risks involved with swapping props it's hard for me to say the performance improvement was worth it.

I would like to believe it. It would be so nice! It would be a simple, relatively inexpensive, DIY-able mod.

But, based on my extensive personal experience with a single engine boat and a vast amount of data from jet skis (all with 1.8l Yamaha engines), I would wager a bet* that a new OEM impeller will smoke a Solas (such as Concord, not a dual prop etc.) out of the hole. (Solas may get a boat to a higher top speed though. )
Implicit in that prediction is that a boat with an OEM impeller(s) will plane with heavier loads.



*I'm not actually betting any money, I just like that expression.
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[Ronnie]

@swatski , I don't need to tell you to believe what you want but my experience is just that, mine, by the way, i have a lot of it. I will add that On my 242 ls i can see the difference in the tachometers. With the stock props when I would go to wot quickly from idle the Rpms would jump up a few hundred Rpms before dropping back down a little as the props hooked up / stopped cavitating. This doesn't happen with the custom pitched Solas props, just smooth acceleration all the way to the rpm limit.

Before upgrading my props I didnt read a lot about what works or has worked for others. I just went down to my trusted PWC shop that sponsors local racers and freestyle pros (including two former freestyle world champions) and asked them what they recommend and why. None of their sponsored riders nor the shop owner uses a stock prop because they are not after stock performance. They all use props pitched for acceleration out of the hole, more so on the freestyle skis. They also stated that most stock props have the best balance between acceleration and top speed. it's no secret that the two are inversely related so if you want more of one you have to give up some of the other.

By the way, I have a wave runner with a 160 hp 1,052 cc mr1 ho engine in it as well as the two different stock props from by 242 ls and possibly the stock prop out of the ski (it has a Solas aftermarket prop in it now that was installed by the original owner) but i don't think the props of the ski and boat are interchangeable as the shafts seemed to be different diameters and needed different Impeller tools (spline holders) to remove the props from them. I could be wrong about this but it really would not matter since I'm not motivated to experiment with changing the props on the ski, it's working perfectly as is and I'd rather spend the time on the water or doing something else.

 

[swatski]

@Ronnie I could be wrong of course, what you are describing is quite opposite of my experience, but it does sound like the Solas are working better in your 242, and the way you are describing it - is convincing.

My experience is exclusively with a single engine 190, which is a big caveat. I have always assumed testing on a single engine would be more rigorous (and of course simpler) but these boats have enough idiosyncrasies. So, your results here must stand for twin 1.8s.

To me, this indicates the subject is re-opened, when I thought it was closed...

As an aside, I don't know anything about freestyle skis but think those are a different bird. And the shaft holder tool I use WR007H fits both 1.8 and MR-1 shafts, as far as I know. There are different tools, too, but the shaft diameter is the same.

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[swatski]

@Ronnie One more thing. Not to argue, but if I understand it correctly, the OEM impellers you replaced with new Solas must have seen some five years of use (or something like that). May still be in fine shape - but I would not expect those to hold the specs.

As much as I would like to believe there are benefits in aftermarket props, there just aren't many apple to apple comparisons. I think for now I'm going to believe my own testing.

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[jcyamaharider]

I do not think anyone here is arguing with you @swatski . I know I enjoyed reading all of your test posts and with having a newer boat with impellers that haven't seen that much wear you probably seen a more real world difference. I, like @Speedling ,would like to see what brand new set of impellers for my boat would do, BUT the upgrade to a stronger material was worth it alone to me. I might have seen an exaggerated improvement because my impellers did show signs of cavitation. I also wonder how much those pump cones helped, of course you did test separately. I know all of the freestyle ski guys pump cone is a very short stubby nose cone for more holeshot.

 

[DCB-270]

I'm in the middle of adding Solas from Impros on my 09 212SS MR1. My hole shot was much improved but only got 9200 rpms. So they are on the way back to Impros for rebending.
I had Solas Group K impellers on my Exciter and Lx2000 and they worked very good. Hole shot and 1-2 mph on top.

 

[Ronnie]

@swatski , I already blew / spent my two cents regarding this conversation but in response to your comment I got the boat with 100 hours on the engines, I replaced the impellers before 200 hours, just eyeballing the impellers I can tell you they look fine, the blades are not bent or chipped. The boat performed the same with them from the day I got it to the day I replaced the props. Are they in the same condition they were in when they were new, probably not but unless or until the Solas wear to the point that they give me the same performance as the stock props I'm going to believe my own experience, which is not limited to my current boat but extends to other jet boats and numerous Pwcs.

Putting an an impeller designed for use on a 1.8 L engine into a boat or PWC powered by 1 L engine does not sound like a good idea, even if they are interchangeable. I say this because the engines have or are limited to very different rpm ranges with the 1.8Ls maxing at 7,700ish RPMs and the 1L maxing at around 10,200. Yamaha already adjusts for differences in RPMs by putting different impellers into their pwcs with ho and non ho engines which have different rpm ranges. At least that is what Yamaha did on the 06 fx cruisers (I had a non ho 998 cc, 140 hp engine) and have an ho (1,052 cc, 160 hp eninge) the stock impellers are not the same). When I asked about swapping impellers between the two I was told not to bother, that I'd be better off getting and installing an impeller that is tuned for my ski rather than installing an impeller tuned for another ski hoping for a performance gain. This From a shop that could have told me the opposite and charged me to perform the switch.

 

[Ronnie]

If anyone wants to try stock Impellers from a 242 ls (1,812 cc non carb boat) out in their 998cc or 1,052 cc mr1 powered boats/pwcs, you can borrow mine, just cover the cost of return shipping when you are done.

 

[swatski]

Guys/gals, I'm looking forward to your impeller performance reports! The more information the better, as long as it's real.

On that different note, "Putting an an impeller designed for use on a 1.8 L engine into a boat or PWC powered by 1 L engine does not sound like a good idea, even if they are interchangeable..." - well, all these boats and skis use everything on a spectrum, from extreme slim NuJets to duals. Not sure what the point is here.

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[swatski]

ok...i know what @jcyamaharider thinks...but what is the concensus of the members if changing out impellers really can make a difference with the hole shot power. i'm not concerned about losing top end by a couple of mph but really would like a bit more off the line. i've looked at the past posts but would like a fresh opinion of those that have made the change.

@bobbie Looking at the big picture, here are my thoughts.
If you are after the hole shot power, I think you may benefit from an anti-cavitation cone (such as Lucky 13) far more than any impeller changes.
Unless:
1. your impeller is beat up, worn etc.
2. you are at elevation and are trying to adjust for max RPM to get into the torque peak
3. you are reflashing your ECU and want to take advantage of moving the rev limiter settings

Other than the above, I doubt you will be seeing substantial gains in the hole shot playing with impellers alone. I could be wrong.
I wish I was wrong, actually. I tried very hard, came around full circle.

On the other hand, Lucky 13 cone is quite amazing. Check out the video clips in post #25. https://jetboaters.net/threads/anyo...ce-adjustable-pump-cone-in-a-boat.7967/page-2
It is very effective in suppressing cavitation. Works well even with unmodified OEM venturi. Also a great tool for fine tuning your RPM. Add/remove a spacer to adjusts RPMs in small increments. If I want my new two pumps totally synced up - hard to think of a better tool.
The important part is just the first few seconds of both clips. Note the difference in the duration of cavitation during the first 5-7sec of out-the-hole shot, before (first clip) and after (second clip) L13 installation and tuning.
In both cases the operation of the throttle was the same - WOT (slammed down) from a complete stop.
Before:

And after:

The difference is amazing. You will see in the second clip - cavitation is essentially gone! There is like a fraction of a second spike in RPM, not hitting the limiter, and the pump just hooks up and pulls.

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[Bill D]

@swatski, are you going to put Lucky 13's on your new boat? The difference in the video is impressive.

 

[swatski]

@Bill D That will definitely be my first mod if I feel the pumps cavitate. I'm still in the break in period, so no idea what to expect when I start pushing.
My initial impression is the twin is SO MUCH less prone to cavitation.
I'm going to wait until I get a good sense of the baseline performance. But after that... L13 is probably going in.

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[ar240owner]

Man how much is the l13 ? I'm having cavitation on my starboard motor and I wonder if it will cure it ?