I have heard for the best top end with speedmasters at high speeds you should keep them tucked in .Is this true . I guess these are called surface drives .Not much in the water is it .

I suppose it matters what boat they are on and how they are mounted. My boat has 2 4s and 1 3. Boat does nice in 1-2 feet with them out about line 3-4 on my indicator. I just bought the boat in the summer, so I haven't had the time to figure out what line 3 relates to in terms of drive position.

I take it you got a new toy for Christmas! Trim it out till it start to drop off speed and the RPM go up, then bring them back in. Every boat is different. Hope you can come by New Years Day.
Tommy

Its way different from a bravo setup. Bravos start with negative trim when their all the way in. My speedy 4 uses very little trim . Very easy to over trim and loose speed. Every transom angle is different. Get good indicators and a GPS and go to town.

I am looking at installing a pair of 4's. Are parts available to rebuild them?

I was told that #4,s are faster than #3,s because of the shorter gear case and less drag. If and only if you can carrie the nose of the boat. I opted for the 4 over the 3 for that reason. I was told if its hard to plain off it will be fast, not true it still has to be deep enough to carrie the nose, Im not having much luck on flying the nose yet but im not giving up. I have a 30ft single V bottom. You can add spacers to the 4 to lower the drive but they are not very hydrodynamic. Actually square in the front. Also plaining of was a problem because the 4,s dont have a cavitation plate so I made and added one now no problem with that anymore. Myself would opt to go with a #3 if I had to do it again. And back to your question, most parts are still available. Gears are not if its a pollygone shaft. The older ones are. Mine drive is a polly, but their is hope their is a company that can put a poly shaft in newer gears. And last you can expect to loss some speed if converting from a bravo setup , the tranny and drive are like sponges with HP. Im down about 5 MPH.

Can you get 4 blades for a speed master ?How much ?

You can get the 4 blades in small shaft used for around 1700-2500 and large shafts slightly more maybe 2200-3500 depending on prop size and work done on them. Typically large pitch/dia seem to be more in demand.

Odd thing i noticed , In the driveway when one motor is put in gear the boat instantly shuts off. Does a drive problem exist or transmission problem .Prop spins free when in nuetral while boat is running .Im thinking the idle might be a little low .Any thoughts .Wanted to trouble shoot but it started raining HARD

Does the engine die or does it lock up?

Could be the drive or the trans if the motor locks up when shifting. If it just stalls, you either have to richen up the carb a little or you have a vacuum leak.

Need to know more details.