Pump or motor - where to put $$??

[Kachinalazer]

I've got a 21' Kachina Lazer, and I just put a brand new SBC 350 in it. Did the rebuild myself, basically stock (a little bit of cam) with a Weiand manifold, spared no expense (Balanced, bored and align bored, decked, etc.) The thing screams like a banshee and purrs like a kitten at idle. I'm very happy with the motor and the way it turned out, but after a few weekends now, my suspicions are confirmed - little motor in huge jetboat=slug! I wasn't looking for a raceboat, I was looking for a cool family cruiser, and I got it. I'm not too upset that it tops at probably right around 50 at best, the problem is pulling a skier out of the hole. Granted, we never had less than 4 adults and 5 kids in it when trying (it's a mini-daycruiser style open bow so it will hold quite a party), but if the skier isn't fairly experienced, it's hard to get up, not to mention the drowning the skier must endure out of the hole. I still don't have much money in the boat as I got it for a song with a blown motor, so I'm wondering whether I should build a bigger motor (BBC or SBC 383) or should I have the pump redone (I'm sure it's tired). Which one would give me bigger bang for the buck out of the hole?

[Jetmugg]

Kachina:
Definitely start with the pump. Get the clearances set right, have the impeller machined to best match your engine's output and desired rpm range. Your holeshot will improve for sure. If you are still not satisfied with the overall performance, then add more HP. If you just throw more HP at it now, it would be like putting more power in a car with a slipping transmission. Getting the pump redone first might get you to 55-60 mph, and your pulling power should be noticeably better. Also, if you don't have a Place Diverter already, spend the money on one now.
SteveM

[Omega21]

Throw the 4 people out on the beach! Make them go get you a beer!
I don't think I'd completely count out the 350 though. I thoroughly believe the SBC can be built to make some pretty good power. Given you're not out to have a lake racer, I think a 350 would be a pretty good choice if built right.
But before I went anywhere with the engine though, I'd find out what kind of shape that pump is in and what impeller is in it. If you don't know, have someone who knows their stuff about jet pumps look at it & give you their opinion. Where are you located? Maybe someone here could turn you on to a pump guru who lives close to you.
Todd

[FastRat1]

i totaly agree with Omega...throw all the adults out lol...and maybe the kids also..but...seriously...i do agree with jetmugg and omega on the pump issue...get it looked at..so u know exactly what u have..i believe there are some reputable pump builders in ur area..re-building (balanceing, blueprinting etc) is not cheap..but i think the money spent there will help a great deal in the long run..as far as the motor goes..i agree..dont count it out..it is a very gd motor..a few things u might wanna play with is..ck the cam for what it was designed for(torque, mid-range, top end)..also u can play with carburation..someone mentioned in here that jet boats like alot of CFM..u can also play around with the timeing (advance or retard)..these are things that only cost time..not money..u have a great place up there to ck everything out (San Ruis Res) on the lower lake..its awsome..especially when its glass...well thats my 2 cents worth..gd luck...ron

[Jungle Boy]

Sounds like you're packing an extra 600 lbs of weight at any given time. Weight kills any boat; jet or eggbeater. Like Omega says, dump a few folks out when you need to pull a skier. For hole shot you will want to have a bigger impeller (A), but it will hurt the top end of the boat for sure and may not allow the engine to run up into it's torque band. It is a trade off in your case: more hole shot or top end. Was the engine ever dynoed? We run plenty of small blocks in our aluminum boats up here and they work fine, as long as the boat is light and they are pulling into there torque curve.

[Kachinalazer]

Thanks for all the opinions, sounds like the pump is the place to start. I've recently had some experience with Glen at Pleasure Boat Specialties here, and he's a great guy and runs a great business, I'll probably have him do the pump. Can't really dump any people, I bought it to get the kids away from the friggin' Playstation so I made a committment for family fun, which means a big party every time we go to the lake. Lotsa kids and lotsa friends. I could probably lose the girlfriend, but that wouldn't save all that much weight and my motor wouldn't have a blower :D
I'm running an RV cam and the thing sips gas, so I'm willing to give up some fuel for some power, so maybe that's an avenue. The thing has dual 20 gal tanks so maybe I'm carrying another 100 pounds too much there too.

[Foolish]

No offense to Pleasureboat specialities but they are $$$$$$$$! He wanted $200 more to rebuild my jet pump than CP performance did. I live in San Jose and I do go to CP performance for all my needs (its in Ronhert Park). Its worth the 1.5 hour drive.
I also got my place diverter from CP but before I did I also checked with Pleasureboat....they wanted $900 for the complete hydraulic place diverter....I paid $754.77 out the door at CP. :D

[BrendellaJet]

Kachinalazer:
Can't really dump any people you can still bring them to the lake, just dump them all on the shore, and let them take turns skiing. If they aint in the water, and they aren't holding an orange flag, tell em to go build a sand castle until you come back.

[Heatseeker]

John, give Walt of Walt's ***boat a call at 209-521-WALT. He's out in Modesto. He can help you decide which way to go. He has alot of pump experience and he won't steer you wrong. He's helped me out alot.