Superjet revs high but now power

Hey so I recently aquired a superjet and yesterday was my first day running it in the water and it was not a huge success. It idles fine and runs well if your just slowly putting around under 1/4 throttle but as soon as you want to open it up it seems to rev out and have no power (it hardly moves even at full throttle). Like I said it runs fine down low ut has 0 output when you get into the high rpm's. I am new to this thing so I don't even really know where to start. Would love to hear some other peoples thoughts on this.
 
Sounds like your driveshaft is stripping but you would probably hear it happening. Does the ski just stop moving when you give it throttle
 
I've had this happen several times with different skis. It's typically something caught in between the impeller and wear ring. I've even had grains of sand get stuck in there and make that happen. It just needs to spit it out. Usually takes about 5 minutes of quick rev ups and it will grind down the sand grains enough to send them through. If it's not sand, then you may have a little piece of waterlogged bark stuck in there. That will require some intervention. I had a bark strip get caught in my SJ too. At this time of year it's especially popular of a problem because the higher water levels will float a lot of shoreline debris.
 

be_lain

Currently sending it
Location
Oregon
Check the pump seal. Remove pump, inspect/replace seal and install with grease or silicone around the seal. I use a ratchet strap around the pump hooked to the bow of the ski to get the pump sealed properly against the shoe. Don’t forget to re align your pump, midshaft and motor when reinstalling.
 
I've had this happen several times with different skis. It's typically something caught in between the impeller and wear ring. I've even had grains of sand get stuck in there and make that happen. It just needs to spit it out. Usually takes about 5 minutes of quick rev ups and it will grind down the sand grains enough to send them through. If it's not sand, then you may have a little piece of waterlogged bark stuck in there. That will require some intervention. I had a bark strip get caught in my SJ too. At this time of year it's especially popular of a problem because the higher water levels will float a lot of shoreline debris.
 
I've had this happen several times with different skis. It's typically something caught in between the impeller and wear ring. I've even had grains of sand get stuck in there and make that happen. It just needs to spit it out. Usually takes about 5 minutes of quick rev ups and it will grind down the sand grains enough to send them through. If it's not sand, then you may have a little piece of waterlogged bark stuck in there. That will require some intervention. I had a bark strip get caught in my SJ too. At this time of year it's especially popular of a problem because the higher water levels will float a lot of shoreline debris.

Ya im not to sure because last night I took apart the impeller looking for debris but it seems to be clean. I also took a look at the driveshaft and it looks like it's fine aswell. When i hold it wide open it just seems like its not pushing any water making the ski move very slowly. When I was looking at the impeller it seems to be severly damagaed, all of the fins are folded over and bent. Could this be causing the problem aswell? The engine feels strong, I checked the reeds yesterday aswell and they are all good. Impeller.jpgshaft.jpg
 
Check the imp
Hey so I recently aquired a superjet and yesterday was my first day running it in the water and it was not a huge success. It idles fine and runs well if your just slowly putting around under 1/4 throttle but as soon as you want to open it up it seems to rev out and have no power (it hardly moves even at full throttle). Like I said it runs fine down low ut has 0 output when you get into the high rpm's. I am new to this thing so I don't even really know where to start. Would love to hear some other peoples thoughts on this.
Check the impeller
 
There's the problem...you have an impeller stuck in your impeller lol. Look at that trailing edge, impacting the wear ring so severely it gored the beans out of it. That's trashed up so badly I wouldn't even question salvaging it. New impeller, wearing ring section and pump seal. There is most likely enough material gone from that wear ring that a new impeller alone will still have very poor performance from too much clearance. Check the stator section too, if you see broken chunks out the veins you might as well replace it too.
 
JetManiac right here on the X :) or browse the parts for sale forum. At least with Chris (JetManiac), you can be almost certainly sure the parts are available. He has everything you need and his shipping is Superman fast :D Don't buy these parts from Yamaha, you will pay out the nose for them compared to a clean used item here. Where about are you in Canada? Southeastern Ontario region?
 
JetManiac right here on the X :) or browse the parts for sale forum. At least with Chris (JetManiac), you can be almost certainly sure the parts are available. He has everything you need and his shipping is Superman fast :D Don't buy these parts from Yamaha, you will pay out the nose for them compared to a clean used item here. Where about are you in Canada? Southeastern Ontario region?
I am over in British Columbia.
 

Vumad

Super Hero, with a cape!
Location
St. Pete, FL
Ya im not to sure because last night I took apart the impeller looking for debris but it seems to be clean. I also took a look at the driveshaft and it looks like it's fine aswell. When i hold it wide open it just seems like its not pushing any water making the ski move very slowly. When I was looking at the impeller it seems to be severly damagaed, all of the fins are folded over and bent. Could this be causing the problem aswell? The engine feels strong, I checked the reeds yesterday aswell and they are all good. View attachment 394982View attachment 394983

Your prop is wasted, missing the nose cone, and your wear ring looks pretty rough.

Buy a new prop, make sure you get the driveshaft holder tool and know what you're doing (tips: You need a driveshaft tool for that job, it's reverse thread, might need heat and lube). Also to protect the new prop you should consider getting a new wear ring housing.

While SBT has a lot of less than stellar products, their wear ring housing with replaceable liner is great. The upfront cost is high (still cheaper than OEM) because you need the assembly, but it is plastic so you prop wont get damaged and liner replacements are cheap after the initial purchase (if you ever need one).

Jetmaniac or Impros would be my go-to for that. Go Jetmaniac and order a bunch of extra cool stuff while you're paying for shipping.
 
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