starflite 68.5mph on gps needing more speed.

[aaronmt]

The boats is a 87 starflite with a stock 1987 yamaha 225. Ok yesterday was the first trip out with the jackplate and new tach(tach verified on dyno and is reading rite) with two people in the boat.Rear seat removed for recovering, and bow foam removed for good. After several runs with the jack plate in different positions we got a best reading of 68.5mph on the gps. It still has the original yamaha factory prop wich is a 13 5/8 23p stainless. The tach was reading 5850-5900rpm. We have the jack plate as high as it would go and it seemed like it was still improving on the chine walking the higher we went. Im wondering if i should mount the motor one notch higher on the jackplate.The boat did not chine walk untill i trimmed it out to far obvioulsy.As to the prop question im wondering if the 23p speedzone will take me out of the ideal rpm range being its a inch larger in diameter. heres some pics of how it is set up it seems like i should have no problem raising it a little more?

 

[aaronmt]

heres 2 more

should i take it up a little more and should i what props you thinking obvioulsy ill be calling boatman, any ideas what rpms this motor should be at?

 

[Boston Predictor]

I think a chopper prop is what you need. I would raise the motor one bolt up.

 

[boatman4021]

jack plate

Aaron, While you have the engine unbolted, raise it up 2 holes or 3 if you can. It's easier to just do it once and you can lower it back down with the jack plate. My 2100 Pulsare and 225 merc is up all the way! Last set of bolt holes and jack plate as high as it will go. I checked and the max rpm on your engine is 5500. 23 Speed Zone would drop you maybe 200 rpm's. Sounds like you have a good start on it. boatman

 

[F150GT]

Call me stupid but I turn my Pro V 200 to 6000, have bean for years(I dont do long speed runs just long enough to get max speed). I had the Stareflight out last weekend for the first time and was running 68 with a 24 four blade. I'll be going back out this weekend to try some other props, I'm confident it will break 70.
I agree with raising the motor all the way up on your jackplate, youl still have plenty of travel down to compensate just watch the water pressure closely. For top speed your 225 should be able to turn more than a 23 pitch.
F150GT

 

[JW]

That 225 should be able to turn a 25" Tempest Plus at 5500 rpms. Give one of those a try

 

[boatman4021]

prop

Hey Aaron, Your new Speed Zone is on it's way. Should be there friday. Thanks, boatman

 

[bostoncan]

Aaron, do you have your top set of holes on the water intake screen plugged ,because you will need to if you keep going up. My spectra had the same 225 excel on it when I bought it. With a porta products lift and i could lift untill no water pressure. I had a laser 25p on it turning 5500 .I may have a shop manual kicking around for it.

 

[aaronmt]

BOSTONCAN , I dont have them plugged but ive also never herd of plugging those , how would i go bout doing that and whats the benifit exactly, Thats the first ive herd of that, thanks Aaron

 

[JUPITER PULSARE]

Keep a close eye on your water pressure as you raise the jackplate. You do not have low water pickups on your lower unit and can lose water pressure and wind up overheating you motor.

 

[Mark]

I don't think the Yamaha has holes like a Merc. Doesn't it have plastic inserts? Maybe someone here knows if Yammie makes "scoops" for high engine height applications?

 

[bostoncan]

No scoops for Yamaha that I could find ,just get a spare set of screens and fill the top of the plastic screens leaving the bottom set of holes open.

 

[supergenius74]

wow thats exactly what the speed I am hitting with mine, I think we need more HP! I looked through that list on the starflite top speeds thread and most boats with 225-250 hp barely break 70, it seems that guys with 73-80 mph are probably speedo readings and not GPS, with a 300X (330hp) he got 87 mph thats 100 hp more than we are pushin. I have a CLE lower unit and have the prop shaft even with bottom of the boat, helps when running a chopper prop but if i switched props to a tempest I would lower it. Remember this is still a heavy boat 1300 lbs, add in engine, fuel, gear, battery, people and you are looking at 2100 lbs+. When your setup is maxed out you can either loose weight or gain HP and thats it. -shane

 

[Costa]

Aaron, I would look into low water pickups, water pressure guage and a temp guage also before raising the motor any more. After those additions get that sucker as high up on the plate as she will go and see how she does. If you want top end numbers I would go with a chopper style prop but it will probably be hell getting it on plane.

 

[aaronmt]

Supergenius, sounds like wed have a preety close race between are two boats. Do u think the extra setback from mine having 10inches would help much seein that were at the same speed right now. My new prop will be here shortly as well as the water pressure gauge and the motor will be up to the last hole. Im hoping to crack the elusive 70 by the weakend.

 

[Mark]

wow thats exactly what the speed I am hitting with mine, I think we need more HP! I looked through that list on the starflite top speeds thread and most boats with 225-250 hp barely break 70, it seems that guys with 73-80 mph are probably speedo readings and not GPS, with a 300X (330hp) he got 87 mph thats 100 hp more than we are pushin. I have a CLE lower unit and have the prop shaft even with bottom of the boat, helps when running a chopper prop but if i switched props to a tempest I would lower it. Remember this is still a heavy boat 1300 lbs, add in engine, fuel, gear, battery, people and you are looking at 2100 lbs+. When your setup is maxed out you can either loose weight or gain HP and thats it. -shane

Yah, I think that's the story on this hull. Without going to big power we are chasing the elusive 70MPH barrier. Frankly, I think that is quite respectable, these are not 600 Lb rocketships. Boating mag just did a side by side on five 21' bass boats, mostly powered by Merc 225 XS Optis and they all ran right around 70! If I break 70 this summer, I figure I am running with the big dogs.

 

[bostoncan]

The best from my 1989 201 spectra with 2003 225 opti is gps 71.6 with a 25p tempest .

 

[F150GT]

71mph with a 200Pro-V Yamaha yesterday. I am very happy with the performance of this hull, the boat rides and corners nice but can still get up and boogie with the right set-up.
So far I have run a 4 blade 24p Soinelli getting 68.5, a 28p chopper Spinelli at 70 and a factory Yamaha 25p at 71. I built a custom set back bracket with a CMC jack plate integrated to give 16" of set back and a max height of the propshaft 1" below the pad, with the 6" notched transome thats 22" total.
As you go back you must go up, at this set up I have full water pressure at maximum height with a stock lower unit.

Caution: Dont try to run this much set-back off of the standard outboard mounting foot print, it WILL break the transome. I built a bracket that has a footprint over 3' wide and 2' tall VS stock at 12" x 13", this distributes the load over a much larger area taking the strain off the center top of the transome.

F150GT

 

[supergenius74]

Yeah I beefed up my transom with aluminum plates before I added the 8" extensions, I have a 16x16" plate on the back and a 4 x 16" plate on the front top engine well. I am still afraid to go back further though. I think i should try differnet props, I love my takeoff though it's on plane in 3 seconds and doesn't take too long to hit 68 mph. If I end up hitting 70 with just me in it I think I can be content with that, the extra 1-2 mph may not be worth it. The one thing I am definitly doing is a foot throttle, I am ordering one this week. At 65+ this thing becomes much more difficult to steer and I like to have both hands on the wheel, also I think I will put one of those helm mounted trim levers so i can trim with my hands on the wheel to, I think doing this might improve my skills enough to gain a couple mph anyways. -shane

 

[merc245]

Witch foot trottle are you going with. I like my land & sea Its the only 1 that lets you choose between hand or foot control.Thats makes putting around real nice & easy.My 2 cents.