Just picked up a spectra 18 and took it out for the first run last weekend.  Just looking for advice on what the trick setup on the pump on these might be.  Right now I have a BBC 454 that is mostly stock.  Pump is a Berk JC with a intake loader and place diverter.  Boat runs good to about 4k then it seems like the pump cavitates and I can't get anymore mph out of it but I have plenty of rpm left.

Without the advantage of touch taste, smell. Sounds like the loader is too deep.... Got pictures?

GT

Not sure what angle you want but here us from the back

Well I got two potential problems I see...

First, that bent to hell keel fin needs to be straightened or removed, I suspect it is causing havoc with the water entering the pump.

Second, the leading edge of the loader ramps should be within 1/8" (above or below) the keel line at it's lift point on the vee, meaning the loader needs to be trimmed so that nothing hangs below the keel more than 1/8", it will likely need to be cut at an angle to get the most out of it.

Otherwise, if the pump is snug and there are no chunks missing from the impeller, you should be fine.

GT

Well I got two potential problems I see...

First, that bent to hell keel fin needs to be straightened or removed, I suspect it is causing havoc with the water entering the pump.

Second, the leading edge of the loader ramps should be within 1/8" (above or below) the keel line at it's lift point on the vee, meaning the loader needs to be trimmed so that nothing hangs below the keel more than 1/8", it will likely need to be cut at an angle to get the most out of it.

Otherwise, if the pump is snug and there are no chunks missing from the impeller, you should be fine.

GT

Lmao...I knew someone was going to say something about the keel fin!  I appreciate the advice!  I will work on tweaking the keel fin and taking a look at how deep the loader is set.  I'm not sure what loader it is.....is there an easy way to tell? 

Like this?


Sent from my iPhone using SoCal Jet Boats

I have a spectra 18 bull nose... have had it now since 2004. Got rid of the keel fin, added bolt on ride plate/shoe 3 degree up, aggresor 9 vane/stuffer, pre loader, straight snoot/4 degree pin and diverter. I still use a rock grate. I get 5100-5200 with a 466 bbf. Rides the best I've owned since these mods.

That's a lot of work done to that pump! Boat looks beautiful though! Nice to get input from someone with the same boat!  Here's a pic of mine from last weekend.

Yup that looks like the one! Thank you

Put the stock rock grate back in.. JMHO.

Here's a link to my over hall last year...
http://www.socaljetboats.com/projects/new-floor-install/