blaster prop help please!!!! still cavitates

extreemthrottle

extreemthrottle

freeride junkie
Location
north palm beach
well i have a stock blaster with a riva scoop grate and new impeller housing. the thing still cavitates really bad. the stock prop i was told was one of the best props for that ski, its in decent shape (no obvious wear or dings) checked the seal even put waterproof grease on it when i installed it, but still cavitates. any suggestions? also i do have a scat track prop for it, it has some wear on it and i don't know the pitch (i checked thier site but no info). the markings on it say "74V" any help with this also would be great..thanks. see ya in daytona!!!!
 
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Sanford

Sanford

ECF
Location
Freeride capital of the world
The stock props do work very well. You rode my Blaster (ironically, just before I sold it) and it had a stock prop. No cavitation or anything and plenty of brap.

If the prop isn't bent, you must have an air leak. Inspect the shoe and the mid/shaft housing. If the bearings are toast or the seal between the hull and housing is shot it will allow air to enter and cause all sorts of cavitation.
 
Shonuff

Shonuff

I've got the glow
Site Supporter
Location
Memphis
Check the seals to see if you are sucking air from the bilge through the midshaft housing or the seal between the wear ring and shoe.

Good Luck.
 
D

duckman1

X
Also on that pump seal, if your pump and engine are not aligned properly, you'll never get that seal to hold, not even with all the ultra black in the world. A word to the wise, once you have proper alignment on the Blaster, do not remove the wear ring section of the pump. pull out the four long bolts and take the unit apart unless you have to take the wear ring out for something. This way you don't have to worry about the seal, alignment, or the locater pins tearing up the locater holes in your hull.

So how do you know if alignment is good, if your pump shaft slides easily into your subshaft assembly, your usually okay, if you need to pound/tap it in, you have issues.

Good luck!
 
extreemthrottle

extreemthrottle

freeride junkie
Location
north palm beach
well, i figured it out. started looking around under the ski again, and found that the pump shoe is cracked.:banghead: :banghead: :banghead:
then i realized when i installed the riva scoop grate, the screws needed to be shorter. went through the shoe and cracked it clear around to where the pump mounts. DOOH!!! looks like retail on a new one is around 85.00! ouch!
expensive learning lesson:scared: anyone got a good used one?
 
yamahammer

yamahammer

are you men the police?
Location
San Angelo, TX
extreemthrottle said:
well, i figured it out. started looking around under the ski again, and found that the pump shoe is cracked.:banghead: :banghead: :banghead:
then i realized when i installed the riva scoop grate, the screws needed to be shorter. went through the shoe and cracked it clear around to where the pump mounts. DOOH!!! looks like retail on a new one is around 85.00! ouch!
expensive learning lesson:scared: anyone got a good used one?
Click to expand...

my b1 pump shoe cracked in half on bottom when i replaced my stock grate also- i glued it with automotive goop and then sanded it smooth- this is the part where everyone chimes in and says thats the worst idea ever and it will cause cavitation- that was a year ago and never noticed any difference and grate is still on solid- your boat your call
 
extreemthrottle

extreemthrottle

freeride junkie
Location
north palm beach
Sanford said:
The only used one you want would be an aluminum version since removing a stock plastic would basically ruin it.

Before you buy a stock piece for $85...have a look at this Blowsion aluminum model for ONLY $88 (its a real good deal IMO)
Click to expand...

thanks sanford, i was told that he aluminum one is pretty aggressive and my ski being stock would slow it down alot. besides my hook up at yamaha got me the oem for 50.00!
 
Sanford

Sanford

ECF
Location
Freeride capital of the world
extreemthrottle said:
thanks sanford, i was told that he aluminum one is pretty aggressive and my ski being stock would slow it down alot. besides my hook up at yamaha got me the oem for 50.00!
Click to expand...
Naaaa....its the JD or R&D model that is the aggressive one. Besides, aggressive means more hook up. I don't care how low in HP a ski is, I always find using deep grate a positive thing.

Please don't tell me G.Y had it in stock...I will fall off my chair.
 
extreemthrottle

extreemthrottle

freeride junkie
Location
north palm beach
still cavitates!!

well i installed it made sure it was sealed up very well. rode it on sat. did'nt cavitate for about 5min..:banghead: then it started again!!!!! :banghead: here's what i've noticed:
it progressively gets worse the longer you ride it.
if you continue to ride longer than a couple of hrs, it makes the engine get hot and start running poorly..

i've replaced the wear ring, the pump seal, and the intake shoe, and still no change. the prop looks good and has minimal wear. i was thinking it had to be either the bearing housing (which i'm looking into) or possibly the exhaust? i know it sounds weird but i'm thinking it gets worse the longer you ride so i'm thinking something is getting hot.
also does'nt the bearing housing when it starts leaking the hull should take on water? its pretty dry in there even after riding in the ocean for a while..
any thoughts on these, or anyone who has encountered the same problem? could really use the input..thanks
 
SUPERTUNE

SUPERTUNE

Race Gas Rules
Location
Clearwater Fl.
What year superjet? What color are your drive couplers? On earlier couplers (ugly pale green) have a plastic plug with an o-ring in the center of them and if they are not sealed or missing they will leak air in the prop shaft and cause problems like you are describing, On full out engine builds, change the intermediate shaft coupler to the later style OEM black coupler that Yamaha eliminated the plastic insert.
P.S. Switch to a skat swirl for it too...
 
extreemthrottle

extreemthrottle

freeride junkie
Location
north palm beach
Mile9c1 said:
If your bearing housing rubber has a tear in it, it culd suck air from inside the hull.
Click to expand...

i think thats the problem.. the rubber seems to be slightly sepperated from the metal around the edges, does'nt look bad but can't be sure. i'm going to do a test and see if it helps, then if it works, i'll change out the housing. btw its on a blaster1. thanks for the input
 
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