STV with 200hp 2.4ltr increase MPH?

[STV_ERIK]

Back Again, Just raised motor so the center line is 1-1.25" above botom of boat. motor runs 5700-5800 rpm 28 cleaver 56 mph? stock 200hp 2.4 with reeds, stacks, tuner, bobs shallow water, 1.78 gear V nose STV :nonod: 80 main jets except 1&6 which are 82. 56 pilot jets???
how do i pick up 30mph?

[Hydrovector]

What model STV?
Sure your running on all six cylinders? I had a 2.4 200 hp on my Euro when I first got it and it had the heads milled .030, plastic reeds and a Hydromotive nose cone with 1.87 ratio stock housing. I ran 28 Mazco chopper at 6800 rpm at 93 mph. the prop shaft was at 1 inch above the bottom of the boat. you should be in the 80's with no problem.

[baja200merk]

Wait.... What???

[albypine]

Wait.... What??? x2 ...wtf? Post some pictures...and did ya pull the anchor to get them speeds or what?

[ProComp]

Did you mean 1:87 gears? 28P at 5700 is 75mph with 10% slip
Something doesn't add up.

[R.grover]

check its running on all 6 like one other guys said not just cranking over but at higher rpm. chcek your tacho is correct and gps cause your stats you have said do not make sence at all

[pyro]

The slip issue makes even less sense than the curious issue of why it can't spin a 28 more than 5800...

Verify that your tach is on the right setting and reading accurately. You probably have a motor issue and a less-than-honest tach reading.

[STV_ERIK]

How about hull conditions, chips scratches the hole for the gear case oil? Bobs shallow water nose leaves a good size hole? how much will this effect speed ? If the engine is spinning at max rpm i dont believe the engine is missing.

[pyro]

...but only if the tach is actually correct.

A 200 should be able to push that hull into the 70's with carpet glued to the bottom. ;)

[STV_ERIK]

I will check the tach next. How about advance module? or stater?

[STV_ERIK]

so... I checked the tach against a hand held digital. idle, 2000, 3000, 4000 no problems. Checked compression, 135 on 1,3,4,5,6 & 140 on 2, now time to try it in the water. Any one have some suggestions

[mistah_max]

whats the hull condition?? is it wrotten? I have a charger stv with a tired 225 yammie and run 75-80mph with a crappy 28 chopper...mine was wrotten completly last year and still would run low 70's. something is defenilty wrong here. post a pic or a video of the boat running WOT. I'd like to see what it looks like at speed. did you weigh the boat?? mine was 200lbs heavier last year when its was wrotten compared to this year.

[STV_ERIK]

boat has no rot, going out today ill see what happens and post pictures

[STV_ERIK]

Here are some videohttp://www.youtube.com/watch?v=X0elYO05scc&feature=plcp still only 55 mph wot 5800 rpm 28 cleaver???

[Euroski]

Do the carbs open fully when the pedal/hand controll are at WOT?

[albypine]

Boat looks to be plowing a little..... Hit the trim and she should take off like a rocket

[pyro]

It should still be in the 70's and turning mid 6's even if the trim is buried full down.

[STV_ERIK]

yes open fully, motor hits 5700-5900 but i think i have to trim up too much to hit rpm. Maybe motor still needs to come up

[STV_ERIK]

Pyro, I agree, this boat had stock everything last year when i bought it, I changed the lower end to a bobs shallow water, new gears etc. I verified 1.87:1 and last year with a 4 blade trophy (it was on it) 25p it ran 68-70. Now i am a bit stumped. Motor may need to come up a bit more?

[pyro]

My Vegas, a heavier boat, used to run low to mid 70's with a stock 200 EFI and a 26 trophy.

Check your timing.

[STV_ERIK]

We had thought about timing, we set the timing as per the manuals but, it did not seem right. Any pointers?

[pyro]

Use a dial indicator on the piston top to determine true zero degree top dead center, for starters...

[STV_ERIK]

yep that was done

[outasite]

What I know about an stv is absolutely nothing,but looking at your post that boat seems to be plowing through the water.How much does it weigh right now today.Is it water soaked.Looks like a boat carrying six or more people.cant get up and break loose!

[Euroski]

Have you checked(casting/block) the engine to make sure it's a real 200hp?

[1611odalys]

Am having the same problem that you are having. Did you ever found what was the cause of it?

[STV_ERIK]

blew a piston but purchased a new power head 2.4 race version and it put out 255 on dyno, works better but i found a weight problem with my boat it was over built cant run cleaver too heavy in bow trying dif props 84mph thats it

[Billy Sedman]

I was gonna say boat seems to heavy for a cleavor, try a big ear chopper or chopper II or lightening e/t. good luck!