Custom/Hybrid 155 Pump Questions

[naticen]

I'm thinking of throwing an OEM 155 into my girl's SJ based ski that has a limited 701. This would yield a pretty cheap mag pump with trim as I already have the pump available and the cavity is ready for it.

The downsides will be, can a limited 701 handle that size pump and can I just cut 3/4" off of the WB2 driveshaft to get it in there quick and dirty for now? When I see how it does, then I'll put in the correct driveshaft, new bearings, a pump stuffer, and a nicer prop. Til then, I just want to slap it together and try it out.

 

[Matt_E]

I'm thinking of throwing an OEM 155 into my girl's SJ based ski that has a limited 701. This would yield a pretty cheap mag pump with trim as I already have the pump available and

No, you'd have an OEM pump, not a mag pump. Bigger OEM != mag pump

the cavity is ready for it.

How so? Unless someone modified that SJ, a 155 will not fit.

 

[naticen]

I know it's not really a mag, but I'm hoping for the good hook up in the wash. I dont know what the "Bigger OEM != mag" means. It's an f1 pro that is nearing assenbly and I already laid the pump in and it fits well.

 

[Matt_E]

I know it's not really a mag, but I'm hoping for the good hook up in the wash. I dont know what the "Bigger OEM != mag" means. It's an f1 pro that is nearing assenbly and I already laid the pump in and it fits well.

Oops, I thought it was a Superjet. If it fits, try it out. You'll need a very low pitched impeller. I don't think you'll notice a hookup difference.

 

[naticen]

Well that wouldn't be cool. I was hoping for motivation to get it done. If it won't be much of a noticeable difference, I'll probably just get her a hooker for Christmas.

Any input on hacking the driveshaft? I hate hacking up good parts, but I hate throwing much time or money into a project that might not get the desired results?

 

[Big Kahuna]

Years ago people were trying 144 Skat Mag pumps on 82-84mm 61X motors, and they were not working very well....... Not enough motor.

A motor can only provide so much power (torque, RPM's & HP). For Every Motor there is a Pump size that works and all the power is Optimized.

If you said you were putting a 1000cc motor in there, then I would say, try it. But with the motor you are running, and a stock porting, you are honestly wasting your time.

But, Just my opinion.

 

[naticen]

Makes sense then. I'll send it back to the scrap pile. If I gotta mess with props and such, sounds like I might as well stick with tried and true.

I was thinking if it worked out well I would do the same for my ski with JetManiac's 781, but it sounds like even then would be hardly worth it.

 

[Christian_83]

Yamaha put a 155mm pump in the wave blaster 2, powered by a 760cc dual carb and thats in a heavier hull and bigger boat. But a 701 limited might be a little underpowered. I would try it with the JM 781 though.

 

[Big Kahuna]

The waveraider 760 had a 144mm pump. There was a reason for that pump in the B2. That hull was limited in the speed it could go

 

[timverhey]

It will work with a decent pitched prop what you will notice is that the powerband is much shorter it will pull much harder but you will loose speed dramaticly

 

[CARBONX2]

I would think the pump and impeller from a WB2 will work quite well in a lighter ski for freestyle if it has a large intake gullet

 

[mxr181]

I know this thread is a few months old but Naticen did you ever get any further with this? What has to be done to fit the 155mm pump in the SJ tunnel? I am getting a Tom21 FX1 hull as well and have a 144 pump and 9/15 hooker waiting for it but I was thinking about this the other day as well. I was thinking along the lines of them running it in the WB2 and the guys that put them in modded B1's also...seems like you would need a lot less motor in a small lightweight hull and Im not very worried about top speed with this ski. There's a wrecked gp1200 I was thinking about buying for the motor to put in a B1 and started thinking about this option as a mag pump is out of my budget anytime soon!

 

[naticen]

The hull that I test fit it in was a WDK F1 which is designed to fit a 155. It required no work other than the right driveshaft but I never did it. I sold the pump and got a prop for the 144. I figured it'd be simple and easy that way since I have way too many projects going on.

As for fitting it in that hull, I'd get a 155 shoe and you probably have to grind a little out of the top of the tunnel to fit it in. The bolt pattern matches up fine and will still keep it centered on the mid shaft

 

[kevbo]

A bigger issue is finding a suitable impeller, Skat made a 7-12 for the 700XL. A larger inlet with lower blade angles will be much more efficient in white water.

 

[mxr181]

Ya I was on the WDK site and saw their 155 shoe which is kinda what got me thinking about it. Def going to start with the 144 pump w/ hooker prop but I am definely interested in looking into the 155mm pump too once the ski is running!

 

[vshockey10]

The oem 155 defiantly fits in a superjet hull. My buddy has a 155 oem pump in his SJ with a 760 in it, rips for sure. You need to use the sj drive shaft. Just simply cutting 3/4" from the end of the shaft will not change the splines location of bottoming out, simply less contact area. For your hull I'm unfamiliar with the driveshaft length required so thats on you. Jet dynamics makes a decent 155 pump shoe that can be modded to fit in a sj, once again not sure how your hull is set up pump shoe wise now.

I ran a oem 155 w a 61x 701 b pipe and a protec rec head. It consistently hit harder than my buddies 62T/61X (stock sj motor 96+) 701 w a riva girdle head b pipe dual oem 38s 9/15 hooker w a 144 mag. The key was a 89mm reduction nozzle and a 7/12 skat swirl.

it works.


99-04 yamaha made a XL700, so 62T/62T yes but still a similar motor yet lighter hulls, that skat designed the 7/12 for

 

[mxr181]

that sounds very promising! Sounds like I will need to so some driveshaft HW then but the hull I am running has a complete SJ intake tunnel so if it works in the SJ it should work in this too...driveshaft is 2" shorter though so may have a little trouble with that.

I will be running a fresh 62T / 61X w/ ADA head (35cc domes), bpipe (SJ mod chamber), and dual 38's and the ski is small and very light! Sounds like this could be a very solid setup!

Ok cool, sounds like the 7/12 could be a good starting point then have impros tweak it from there. I know some of the new freestyle hulls are running 155mm pumps so maybe that will help with prop options...hey impros how about a low pitch 155mm hooker prop???

 

[vshockey10]

I should mention the 7/12 is a small hub swirl. Just go with that

Skat makes a 155 large hub swirl impeller. The root pitch is just to High to be tweaked down and work with the small motors. I have a 8/15 large hub skat swirl for my 898 PHP motor now.

You can take what ever drive shaft you have from your donor 155 and send it to jet maniac. He can custom cut it to the length you need.


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