prop pitch and jetting for Dasa 900

[swannysxr]

Hey, looking for input on recommendations. My setup is Thrust built 4mm 900 Dasa 190 psi,Novi 48 carbs, Skat 145 mag pump, 85mm exit nozzle, 90mm steering nozzle, tbm flywheel, modded b-pipe, have an enhancer, but want to do Epic or total loss. looking for similar setups. Any input would be appreciated, Thanks

 

[chadetroit]

I know input from my engine builder and impros has both been 11-17 on a very similar build. 144mm pump

 

[swannysxr]

Nobody else has similar setup??

 

[skinnyman]

6 mm 920 dasa 12/17 skat witha 144 mag

 

[Pablo]

Swanny I tried to pm u last night.

I'd go 11/17 or 12/17-18 with a 85-85.5 nozzle. Stubby cone, and a 91 steering nozzle.

I ran that 13/18 and it was too tall. I tried unloading it with 87 nozzle. Decent results but I would pitch down from a 13/18 and try the 11/17 with a traditional nozzle bore 85 and play with tail cones.

 

[swannysxr]

Swanny I tried to pm u last night.

I'd go 11/17 or 12/17-18 with a 85-85.5 nozzle. Stubby cone, and a 91 steering nozzle.

I ran that 13/18 and it was too tall. I tried unloading it with 87 nozzle. Decent results but I would pitch down from a 13/18 and try the 11/17 with a traditional nozzle bore 85 and play with tail cones.

Hey Gregg, just
talked to Brian at Thrust, I'm going 10/16 for maximum hit, Impros and Skat reci. the same. exit nozzle is 85, and steering is 90mm.

 

[Pablo]

Good info. Keep me posted on how it goes. I've been anxious to hear. I'll prolly never come north again...in my lifetime, but if u come south look me up. Our lake is like 10" off I 75S. Good break spot on way to Florida.

 

[swannysxr]

Sounds good Gregg, I'll let you know.

 

[geraban19]

Precious infos here.

 

[swannysxr]

Update, Iv'e ended up with the following setup. But the low end still isn't as crisp as it could be. Any input would be greatly appreciated.

Dasa +4mm 898
Novi 48's
135 pilot
125 high
2.5 n/s
115 g spring (20 psi)
Epic HX3 ignition
ported B-pipe w/mod chamber
Skat 145 setback mag pump
10/18 skat thin blade swirl
exit nozzle 85mm
steering 90mm
stubby cone

 

[masterblaster]

interested in trying one of these skat thin blade props,whats your impression of it in comparison at those pitches? id like to try one with a smaller spread,11/15 range maybe
Have you tried jetting up just a bit? novi carbs do well reverse jetted, try 130 high 140 low increase pop off 2 lbs
at least 33 deg timing off idle with epic tbm fw
half inch water fitting into motor from pump,separate 1/2 inch cooling circuit to bpipe close both bottom water screws in b pipe open top screw about 1/2 turn

 

[swannysxr]

interested in trying one of these skat thin blade props,whats your impression of it in comparison at those pitches? id like to try one with a smaller spread,11/15 range maybe
Have you tried jetting up just a bit? novi carbs do well reverse jetted, try 130 high 140 low increase pop off 2 lbs
at least 33 deg timing off idle with epic tbm fw
half inch water fitting into motor from pump,separate 1/2 inch cooling circuit to bpipe close both bottom water screws in b pipe open top screw about 1/2 turn

Yea I was going to try the 140L, 130H next and drop my n/s to 2.0, Malone rec. the thin blade 10/18. But when it does run good I feel like it's slipping down low and still has crazy top end, I have an 11/17 to try also (BTW this is a Kawi mag pump)

 

[masterblaster]

not much diff in 144 and kawi 145. Ive heard that the thin skat thin blade props are "suppose" to flex and sorta clutch up off the bottom to run higher pitches so you can get in your pipes power band quicker,perhaps this is what your feeling,I just dont see how its possible really,im guessing thats why they put such a large spread on them, I cant see a prop flex and come back correctly even if the blades are a little diff being thinner. trying to move that large a volume of water with a 8 point spread through the pump at once,would seem to facilitate this in theory though. dunno though,there is so much smoke and mirrors and snake oil with props though..what ever it takes to sell a bunch more next yr seems to be the norm. I personally dont think much has really been that much better since the 13/18 swirl design cut back 3 mills for most skis

deff try the reverse jetting on those carbs,it works very well,what timing and pipe settings you runnin? try some quick things with the motor to really see if your prop is slippin,or if your over proped,try removing the ball from the jetworks valve and let the waterbox take a bunch more water to slow up the revs on the low end of motor and see how the prop responds to that.or a little more time consuming and in the other direction switch out the reduction nozzle to a 82 mill stocker

 

[ou812]

I'm running a very similar set up and think there's a little more low end hit to be found too. When I went to TL from enhancer I was expecting more out of. I started off with base timing at 26* and bumped it up to 28* or 29*. What is your base timing at? Is 33* safe on pump gas? For me the 11/17 Hooker works well, 10/16 hooker slipped some and a 11/14 hooker seems to be working the best so far. Its allowing the engine to rev out a little quicker. I have a Power factor on order so I'll see how much that helps. I think there is a mod to the power valves that helps with bottom end hit and machining the cases to lower the port timing.

RN SJ
Dasa +4mm 898
185 psi compression
Black Jack 46's
135 pilot
125 high
2.5 n/s
26 psi pop off
MSD TL
Ported B pipe mod
Solas 144 setback 3" mag
11/14 Hooker
Exit nozzle 85.5
Stubby cone
Stock steering nozzle diameter

 

[swannysxr]

Thanks Masterblaster, I found the real problem last weekend. My pickup tubes slipped off the 90' fittings inside my fuel tank.