Philip

Hi Nauti,
Glad to see things are going in the right direction, Tell me the new info. rpm. at wot. speed, which props, and which way are they spinning? I was going to talk to you about the centerline measurements of the prop shafts, Most people rig the motors too far apart.This weekend I will go over the heights and the centerline meas. I feel these meas. are very important. Please let me know the rpm etc. did you feel the boat fly better with more positive trim?
Philip

mjuwalters

I was able to run my boat this week end .With two people app. 40 gal. fuel speed 109.2 hard on the rev limiters. I guess I will not see much more untill I send ecus to rapair. It did accelrate much better and was more nimble without the extra bow weight. Thanks for the help, any other ideas I would glad to listen to
Mabey I'll get a chance to come down to jersey. I would like see what difference it would make running in salt water

Thanks Michael:
ps the 300s seem to shift fine even with 34s

mjuwalters

speed

Philip

mjuwalters,
If you sent the 34's to the rev limiters, (6,000) rpm there is only one thing to do, Raise the limiters. I am glad the boat feels lose and flighty. 109.2 is very good. If the limiters are set for 6450 and you hit them your speed will be awsome. I don't think the 34's will get to 6,400, but I sure hope so. The boat must be running nice and light if you feel the 34's are spinning up fast. On our 32' Skater the 34's are too fat. Sat. I am going to check the centerline meas. and post it for you. I would like to know what your engines are set at. Meas center of prop shaft to center of the other one.

Philip

mjuwalters

Philip The motors centers are 62in. as reconmendated by motion. This hull has a wide tunnel at 45in. I still had have good water pressure port side14lb starb side puts the 15lb gauge on the pin. I going to raise the starb. motor just a tweak. I will have the rev limiters reset, but I do not expect 400rpm increase but if there is 50 rpms left I want it. Know what I mean? Thanks for you advice. I will keep you up to date.
What year is your 32 twins or triple what speed are you grtting ? I just sold my 32 hydra tech with triple v8 evinrudes. Was able to run 97 on a good day. The new owner is a good friend. He has motors at wayne taylors for the full works. Iam curious to how it will work out for him . Have a good weekend mICHAEL

Hydro

My Port motor still only revs to 5700. I am waiting to down load the computer. When you are running 97 does the boat feel like it is flying? If you run into the wind it should lift the hull and go faster. Even with both motors turning less than 6,000 I see a 3 MPH difference running into the wind. I have over trimmed my boat and still does not seem to pack enough air to fly the hull. I will take a prop shaft CL measurement Sun.

Aqua Nut

Hey Hydro, how many hours are you up to now? That is one beautiful looking boat (and crew!) I sure had a blast running with you in Long Island Sound.

Sounds like you really need to get those motors pluged into the computer and see what it says. Does anyone know if the New 300x has a programable ECU? Can you adjust the rev limit at all or do they have to be sent out to have the rev limit set at 6700rpm? What is the maximum "Safe" RPM for these 300x's

T2x

I believe the 300x's are supposed to turn 7000 RPM and produce about 330 HP at that speed. However, Powerboat alluded to a "dyno sheet" that Jim S. at Mercury showed their writer indicating 327 hp at MUCH lower RPM... The writer seemed like a bit of a dope so it might have been a mistake.

MJU....With all due respect to your manufacturer.....those centerlines seem MUCH too wide apart.....IMO.

T2x

mjuwalters

T2X Thanks for the input. What are the centers on your 28, how wide is the tunnel? Om my 33 ft hydratech the centers were57in. but tunnel was not as wide .What effect would wide centers have? Thanks Michael

T2x

Mike:

The Hydra tech info is probably not equatable to your new boat as the HT's had a lot less tunnel lift. Generally, I suggest OB centerlines to be approximately..3 1/2" outside of the tunnel wall....... This places the prop in the max water flow exiting the tunnel and makes the boats more responsive in turns....... However, this can aggravate boats that are spinning "backwards"..... (spinning "in"......which I am against in any circumstances)....... since the closer positioning of the motors narrows the "stance" somewhat and can reduce the lateral stability which is already badly compromised by reversing prop direction.

Good Luck

T2x