SuperJet Problem

[skisinker]

Hey guys. I have just fitted a 144mm Solas Mag Pump to my 2010 Superjet. The ski is 701, stock head, ported, with a B-Pipe, and it makes great power. Or did! After putting the pump on, I noticed that it was not reaching the usual top speed. Feels ok for the first half of the rev range but beyond that it feels sluggish- seems to stop hooking up and never reaches the top speed it used to.

I had left on the stock 2010 prop when we installed the Mag (knowing some consider it is wrongly pitched for the above set up, while others don't) and I figured this was probably causing the problem. I then bought a Skat Swirl 13/18 C75 large hub. Having fitted this, the problem remains. I really can't tell if it's not hooking up or if the engine itself is bogging maybe. It feels crisp enough through the rev range up to that point though.

Any ideas on this would be really welcomed, I'm pulling my hair out and seriously regretting having bought the Mag Pump. The only idea I have had was wondering if the pump nozzle is trimmed in slightly the wrong direction for the new pump. I was going to get the spanner out and re-orientate it differently to see if that made a difference.

 

[DAG]

Did you silicon a "new" pump seal in when you replaced pumps?

 

[skisinker]

No we didn't. The pump seal looked in v good condition so we left it as is....

 

[schicks]

its usually a good idea to put a little silicone on the pump to shoe seal, just incase there is a gap that you can't see.

did you use the rubber spacer or metal spacer ring that goes between the stator vein section and wear ring? did you use silicone on that as well? Reason i ask, when i installed the solas mag, i had the rubber spacer ring (came with pump) and it didn't fit at all, so i bought the metal spacer ring from impros and that took up the gap nicely.

also, how big is your gap from prop vein to solas mag veins?

 

[skisinker]

We used the spacer ring from pump vein to reduction nozzle. Used sealer on all joints although not on the main seal as it was in very good condition. I'm not actually sure about the gap from prop vein to mag vein Schicks, would have to look.

It's made even more annoying because me and a couple of friends got three Solas mags for our three superjets and basically did all of them at the same time. The other two rip and only mine has this problem or has seen any reduction in performance!

 

[skisinker]

Sorry, and we used a metal spacer ring I should've wrote.

 

[Harbor]

Did you get a good amount of pump seal compression to shoe when you had to pry the pump forward to get the front wear ring to hull bolts to align ?

Did you happen to do the flashlight test for seal to shoe gaps ?

I just installed a pump in my hull hopefully it works :/

 

[skisinker]

There seemed a real good amount of compression Harbor, everything seemed snug as a bug and as it should have been! We didn't do a flashlight test, that sounds pretty ingenious.

I hope yours does too bud, it really sucks when your ski worse after the install than it was before the install

 

[skisinker]

I wonder if maybe the 13/18 C75 just isn't the right pitch still and it's the prop issue still.

 

[Harbor]

Frustrating for sure!!! I would have thought you'd be running a 9/15 ish prop with that engine/pump. My superjet set up similar to yours but with ada head and enhancer, I used hooker 9/15 in stock pump. I was running an 11/17 hooker with 8 mil 865 stroker in my Solas. I thought there was some numbering differences between the brands but forget exactly. I just put a 14/19 scat prop in a 148 behind a 16 mil but have not rode it yet, but should be very close.

I was thinking if it's a cavitation issue from a leak say, you should be spinning the prop and not hooking up and or hitting the rev limiter, not bogging...

 

[Harbor]

How similar are the three ski you guys just did in terms of set up and prop pitch?

 

[john zigler]

I answered your same post over at PwcToday.

I have the same thoughts, impeller too steep? Or like I said over at PWCT, check your pump bearings, they may be binding.

 

[skisinker]

Thanks John, I'll do that.

Yeah the three skis we set up are all 701s, mine is the only one with porting. The other two guys elected to go with a Hooker, one 9/15 the other 10/16.

 

[Harbor]

Oh ok, then being over propped is at least part of the issue. . John wrote up a killer article on the Solas pump, not sure if you saw it and Has good prices on parts too.

I'am leaning towards the hooker 9/15 as far as prop pitch goes with the Solas cone to tighten it up a smidgen to start with.

You have stock compression with stock timing curve ?

 

[skisinker]

I was generally aware of Solas pump/bearing issues so when i bought the pump I did also buy an AM bearing kit from the supplier specifically for the install.

Yes the compression and timing are both stock, I have a stock head and stock electrics bud.

 

[Harbor]

Sounds good then

 

[john zigler]

Please keep us posted on your findings.....

I am still betting you are over pitched. The Solas really loads pretty well.

 

[skisinker]

Hi John. I will update the thread as soon as the ski's been to the workshop. I think we're going to take the pump out and check the seals, bearings etc. I'm also hoping to borrow a friend's Impros Hooker and see if a different prop corrects this top end loss of performance. A number of people have suggested this as a likely cause, while a good few others seem to absolutely swear by these 13/18 C75's for 701 ported SuperJets.

The dealer who sold me the prop has been v helpful and he suggested we check the carbs as he thought it sounded like they may not be adequately fuelling enough to carry the higher revs, and to check the timing to make sure the spark is remaining consistent when being revved. Unfortunately that's getting a good way beyond my level of expertise so hopefully this doesn't turn out to be the case. The dealer is very confident the prop is the right pitch however.

I can't wait to get to the bottom of it, it's a nightmare being off the water just as the weather is warming up!

 

[skisinker]

Well we seem to have found a solution. Decided to go through the ski in stages to make sure we knew what had caused it, and after doing all the checks you'd expect to the pump, seals, bearings (and compression testing, crank etc for good measure). This was all absolutely fine and no problems detected.

Next, we decided to change the Hot Hands system set up on the ski back to the standard cooling routing. A local ski mechanic had advised that water pressure in the ski could have been affected by the installation of the pump so with that in mind, and given the water pressure from the hot hands didn't seem too great, this seemed like a good idea. As soon as this had been done, I took the ski down for a test and it seems to pulling fantastic, nice and clean all the way to top speed! The engine feels generally crisper too throughout.

I hope this is a permanent solve, very happy indeed with how it just ran, the problem seems totally gone!