What Pump Combo 4 A Big Bore+5mm Mtr

[GIL]

Lamey 85mm +5mm stroker/flattop fed by dual Full Spec 48's w/TNT chamber and a stk ignition +MSD enhancer

To begin with
oem pump
Virgin Trim w/Pro tec 86mm exit nozzle and steering nozzle
Skat 12/17 C75 prop
TBM super pump cone(shortest cone installed)

DOES NOT WORK
middle cone installed-a little better
long cone(race cone) works even better

No matter what cone-still cavitates at times

I am looking for full on freestyle application only-NO freeride.

Opinions??? What I am doing is gettin me NOWHERE, where should I go now?

 

[Kennay]

12/17 C75 prop?

I don't know ******** about it basically, but I googled it out of curiosity. It appears (Everything I found for it) that prop is for a 140mm skat mag pump? 140mm prop in 144mm pump = there is your problem

I'd guess the more cone you have on there the better because it's keeping the pump a little more stuffed

 

[HBCwatercraft]

I know what u need...144 12 vein

 

[njfl]

You need a 140mm Skat pump. You've ridden Charles's ski with his 140. You know it will be a great match fior your motor and it is more efficient than your 144 OEM+TBM. Go with a 14/19-23 pitch prop.

 

[#ZERO]

What's different about the Skat C75 impeller versus the Swirl?

If the longer tail cone helped, you may want to try a reduction nozzle that has not been bored out.

Also looks for leaks around the bearing housing and pump seal area.

 

[Kennay]

So anyone else catch the c75 part?

 

[GIL]

So anyone else catch the c75 part?

It's a new prop that Kevin at Legdrag is selling. It's a 75mm hub 144mm prop designged to turn a oem pump into a ghetto mag(affordable).

U add the prop and a TBM super cone and suppose to have the same results as a mag pump.

I started out w/a conventional Skat 12/17 swirl-sucked azz

then tried my Solas 13/16 -3mm/still sucked azz

now have the C75 loaded-still sucks azz

I honestly think the 86mm exit nozzle is my issue, but have been to dam dumb to snag the stuff off of my wife's SJ to try.

My next plan of action is to try a MAG PUMP(borrowed for a few minutes to test)-then if it still sucks azz-I know I have a ski problem, not a pump problem. If its good, try a 85mm exit nozzle, try no TBM cone, if no go then-throw the dam oem pump in the lake and buy a MAG pump! The F'ing motor feels awesome w/the dam pump hooks up-which is a rare moment!!! Hell, I might just throw the oem pump in the lake so I feel better for about 2 seconds.LOL

 

[tricky1]

Are you sure you don't have any air leaks around the shoe or pump seal?

 

[Mouthfulloflake]

I was spinning a 12/15 concord with an 87mm bored nozzle in a stock pump with a 650.

it doesn't surprise me that you can [at times] cavitate that steep of an impeller and that much of a bored exit nozzle.

if the pump seal is good, I would go to a taller impeller also as an experimental trial.

 

[Cliff]

i dont have a clue what i have but you can try it when i take the pump out this weekend to dual cool it.

 

[GIL]

Are you sure you don't have any air leaks around the shoe or pump seal?

Not really. Would u silicone the seal to the wear ring? And then keep the hull surface of the seal clean and dry? Or lube it for more seal? I've always been too dam lucky w/pumps/prop choices and never had to go thru this. What a pain in the azz.LOL

 

[#ZERO]

Some 3M 5200 will work good around that seal.

 

[GIL]

Some 3M 5200 will work good around that seal.

5200 the seal to the wear ring and leave the hull side dry? I would assume?

 

[Speedfreak]

About the seal I would silicone the seal on to the pump but don't push it all the way on then put a small bead on the seal that touches the hull. That process works best as far as I have seen..

But your problem is the Protec nozzle. The protect nozzle has a ton more room inside it compared to a stock nozzle. The easiest way to explain it is when you bore a stock nozzle out to 85mm the lathe actually cuts a section about 3 inches long and when boring the protec nozzle the cut section is about an inch deep. It was like having 2 or 3 wetwolf cones installed. So the pump worked better with the longest cone because it is taking up the extra room.

Look at this picture you can see that mid way through the nozzle the diameter is a LOT bigger than the stock nozzle.

 

[#ZERO]

5200 the seal to the wear ring and leave the hull side dry? I would assume?

A lite coat on either side of the seal would be fine.

 

[XFT LOU]

I just installed a tbm with a solas 13/16 and a 85mm exit ring. This all in a xft nozzel of coarse. But I'm not in the water yet. Gill, keep us posted on what you find.

 

[Big Kahuna]

12/17 C75 prop?

I don't know ******** about it basically, but I googled it out of curiosity. It appears (Everything I found for it) that prop is for a 140mm skat mag pump? 140mm prop in 144mm pump = there is your problem

I'd guess the more cone you have on there the better because it's keeping the pump a little more stuffed

C75 only refers to the hub size, has nothing due to the size of the pump or prop.

 

[Mouthfulloflake]

I missed where he said he had a protec nozzle.

yeah, they dont have straitening fins, and they tend to cavitate.

About the seal I would silicone the seal on to the pump but don't push it all the way on then put a small bead on the seal that touches the hull. That process works best as far as I have seen..

But your problem is the Protec nozzle. The protect nozzle has a ton more room inside it compared to a stock nozzle. The easiest way to explain it is when you bore a stock nozzle out to 85mm the lathe actually cuts a section about 3 inches long and when boring the protec nozzle the cut section is about an inch deep. It was like having 2 or 3 wetwolf cones installed. So the pump worked better with the longest cone because it is taking up the extra room.

Look at this picture you can see that mid way through the nozzle the diameter is a LOT bigger than the stock nozzle.

 

[crammit442]

This is gonna probably sound wierd coming from me, but I would talk to paul and do whatever he thinks would be best.:wall: He built your motor and recommended the prop, carb, fuel, pump, etc. combo and he will be your best bet for getting it straightened out. I know when Art builds my motors, he has very specific recommendations for every facet of the package. If I were to opt out of some part of his package because somebody on the board thinks it's a good idea or because I had problems initially, I wouldn't have boats that run the way mine do.:wink:

 

[norcal ex]

13-19 mag prop