I don’t like asking this question because this is like talking about tires on a 4x4. My ski is well tuned. I now have a 9/15 hooker that was repitched to 12/18. I only ride flat or lake water. As soon as the water becomes choppy I loose bottom end. I tried an intake grate but that ripped out and is sitting on the bottom of lake besides not a big fan, throttle off brakes on characteristics. The 701 is freestyle ported piped msd lightened flywheel etc etc.... this engine pulls the ski very good mid to upper range. I’m stuck with the poor design pump but can someone explain or convince me on a slightly different prop. Small hub vs big hub, straight pitch etc. I don’t need top speed. Honestly who does? Everybody uses these things for goofing off freestyle. I definitely hear the motor rev and feel the prop spin in choppy water at low speed when setting up to jump wake boat rollers. My search for X2 props is all over the map which is also why I hate this topic but here I am.
Modified 701 X2 prop choice
- Thread starter catpower
- Start date
- Location
- Charlotte, NC
12/18 sounds a bit much on the pitch being the large hub design especially if you're wanting freestyle type ride. I'm running a 9/15 in my x2 with a built 750 and all the bolt ons like you have. If you were going for top speed, the 12/18 would be a great choice. For overall riding I think a 10/16 would be more ideal. This all has to do with the complete pump setup. The taller the leading edge pitch, the harder the impeller will load the engine because it grabs more water each rotation. Much like taller tire on your truck. Outlet nozzle diameter directly affects the setup as well. Larger outlet nozzle, the less pressure is at the back of the pump which will allow the engine to rev quicker and accelerate off idle better. Fine tuning can be done with playing with pump cones. If the impeller pitch is too low or your outlet nozzle is too large, the engine will rev out but the ski wont respond the Same
The 9/15 hooker is a big hub if I recall. Is yours a 9/15 hooker big hub? I started out with this 9/15 on the same motor because back in the day Dave at impros recommended it but I disagree on a strong 701. Talk about spinning a prop! New owner for Impros recommended this pitch. It’s is much better but nothing like a strong 701 10/16 prop in my B1 with mag pump. I know totally different pump and ski. Regardless I’m chasing this problem. What options do I have for exit nozzle or pump cone? I’m tempted to mill out a smaller cone.
- Location
- the jetski grave yard
When a prop spins, it's either too small or its spinning on air. If it's not jumping out of the water like you want at basically a dead stop, why not? Does the motor not rev or does it just spin the prop. 140 pumps are not for bottom end. Old SJ race boats turned 144s into 140 mags and only ripped after they spooled up
This might be an unpopular opinion, but I'll throw it out there. If you're using a stock x2 nozzle, I would try a smaller 80mm aluminum nozzle. With the smaller nozzle the pump will "prime" faster, it takes less total water into the pump fur it to develop pressure and create thrust.
Also be careful with the pitch numbers on a hooker impeller, i haven't measured many and I've icky had the Yamaha version, but it looks too me like hookers use "vanity sizing" and intentionally mark their impellers a few degrees smaller than they are
Also be careful with the pitch numbers on a hooker impeller, i haven't measured many and I've icky had the Yamaha version, but it looks too me like hookers use "vanity sizing" and intentionally mark their impellers a few degrees smaller than they are
My expirience was much different, but I was going the opposite direction of the op. I had a high (ish) revving 650 that didn't have much bottom end, going to a very big nozzle let the motor rev. The pump was looser so the load didn't build until the revs were up in the power if that makes sense.
So I haven't really tried what I suggested. But kind of did the opposite to get the opposite effect.
So I haven't really tried what I suggested. But kind of did the opposite to get the opposite effect.
Quinc
Buy a Superjet
- Location
- California
from all the reading ive done on 650 pumps I would try a 10/18 skat.
My ski sits on a lift in the water all summer so I haven’t been able to study it or take measurements. Before I spend more money on a different prop I’m thinking of a few things to try. 1- I’m not understanding fill and radius the grate. I’ve got a few stock grates so if some modifications can be done I’ll do so but I don’t understand your comment. 2- I’m tempted to weld on a very small wing onto a spare grate. 3- pump cone. Make a new one on my mill and get results like a wetwolf cone on a yami 144. 4- exit nozzle. I’d need to measure mine. Question: Is there an aluminum exit nozzle from a different ski I could use. I was thinking of boring it out then add smaller rings held in with set screws to fine tune it, thinking out loud maybe this can be done.
Regarding describing my problem, all I can say is I’ve played around with jetting and pipe water screws enough to dial out any low end bog. I have an adjustable restrictor to Dry out my water box. I’m using a HX WB with a superjet Pipe. All 2” exhaust including outlet. During my build I filled in the flat area inside the pump where the driveshaft goes using pvc pipe. ( and NO I’m NOT leaking with a poor silicone pump seal.) That’s been asked before. The hooker 10/16 I have with a mag pump on my B1 performs very well getting the ski to pop moving slow. Since a mag pump isn’t available for this 140 pump I’m looking for something that comes close.
Regarding describing my problem, all I can say is I’ve played around with jetting and pipe water screws enough to dial out any low end bog. I have an adjustable restrictor to Dry out my water box. I’m using a HX WB with a superjet Pipe. All 2” exhaust including outlet. During my build I filled in the flat area inside the pump where the driveshaft goes using pvc pipe. ( and NO I’m NOT leaking with a poor silicone pump seal.) That’s been asked before. The hooker 10/16 I have with a mag pump on my B1 performs very well getting the ski to pop moving slow. Since a mag pump isn’t available for this 140 pump I’m looking for something that comes close.
Larger nozzle, stubby cone, and lower pitch impeller are all things that you do to reduce pump load and let the motor rev more. From your description it sounds to me like you have the opposite problem you need more load. You described the motor revving but not going anywhere. I would be increasing pump load. Cheapest easiest way to dfi that is nozzle. $.02 from a guy that hasn't ridden the ski.
The interchangeable ring thing is cool but really nozzles are cheap and easy to swap and if you have the ability to bore your own you can have a handful on hand in different sizes. That's what I do. There are aluminum nozzles from 750's and couches in 76mm and 80mm sizes that you can pick up on ebay. I always just keep an eye out and buy them when I see one cheap. There are aluminum trim nozzle assemblies from couches that will work on those nozzles and it's pretty much a bolt on deal, I have one so I know they're out there but I don't know what ski it came from so you'll have to do some research.
You can actually use a mag pump intended for a 750/800 on your x2. It's not a straight bolt on there is some fabrication involved for the intake grate and pump shoe but based on your previous comments sounds like you could easily handle it. Solas makes one that is relatively low cost (its still more than the Yamaha one though)
The interchangeable ring thing is cool but really nozzles are cheap and easy to swap and if you have the ability to bore your own you can have a handful on hand in different sizes. That's what I do. There are aluminum nozzles from 750's and couches in 76mm and 80mm sizes that you can pick up on ebay. I always just keep an eye out and buy them when I see one cheap. There are aluminum trim nozzle assemblies from couches that will work on those nozzles and it's pretty much a bolt on deal, I have one so I know they're out there but I don't know what ski it came from so you'll have to do some research.
You can actually use a mag pump intended for a 750/800 on your x2. It's not a straight bolt on there is some fabrication involved for the intake grate and pump shoe but based on your previous comments sounds like you could easily handle it. Solas makes one that is relatively low cost (its still more than the Yamaha one though)
I measured the exit nozzle to be 83mm. I’m currently running with no straightening veins. I’m still confused, I asked Impros this same question and was told to go larger on exit nozzle such as an 86mm. I tend to agree with your comment about needing to load the pump in order to build pressure and by running a smaller exit nozzle to 76 vs 83 would help. What modification needs done to allow the TBM to fit the X2 pump? 
Quinc
Buy a Superjet
- Location
- California
Find yourself a jetmate nozzle. They are biggest oem you can get for the 650 pump.
There were some aftermarket aluminum nozzles that started at 84mm and could be bored. Finding one may be difficult now since they have not been made in over 25 years.. A stock plastic 650 nozzle is very good. Some blade bending may be required to get your engine loaded correctly.
There are Kawasaki couch nozzles for the bigger 148mm pumps that have super ridiculously thick walls so they can be bored very large. They need some other modifications to fit on a 140mm pump, but if you have a mill and a lathe it's nothing very difficult. Readily available cheap on ebay. I have two that i made quick and dirty 87mm and 85mm nozzles for testing. That was the testing I did that leads me to believe you probably need to do the opposite.
What is the reason why you suspect a larger nozzle might benefit you?
What is the reason why you suspect a larger nozzle might benefit you?
Honestly I don’t. Or at least I don’t understand the physics of it And some have stated so. Read the above post it was recommended by an impeller shop. But at the same time I’ve read post about taper vs. straight bore to gain more low end thrust. If a small cone such as the wet wolf is sold for this reason then a larger nozzle would also benefit for bottom end response if I understand all this. Maybe I guess H___ I don’t know. Yes I have both a mill and lathe but I need info to ask what is available. Keep in mind I’m in Corn country, John Deere tractors not a slew of Jetski riders found on the X. I don’t think my rpm’s are above 6800. I did have a tach on it last year and knowing my B1 does have a tach and pulls good at 68-6900 I think I’d remember thinking WOW this motor is screaming at 7100 or such. I had a similar problem with a strong 701 in a B1 UNTIL the mag pump was installed. I can feel my B1 pull and lift the front from near dead stop maybe just before 1/2 throttle with very crisp response. The X2 pulls but not til about 5/8 throttle and a fair amount of speed is needed before ya get that arm yank pull. I’m blaming prop pitch because the motor doesn’t stumble or load up,