Mike...mail sent.

Thank you.. Does Diameter, 3 or 4 blade make a difference. Cupped? Knifed?

Heres a Picture of boat..

Nice looking Boat...same exact set up as my '86 272LS that I had 25 years ago...except I had a teak swim platform with 320 EFI power.

[IMG]http://i705.photobucket.com/albums/w...es335Large.jpg[/IMG]

...so I'm familiar with what you have.

Anyway...all props are cupped. If you have cleaver props and they are 23" you are really fighting an uphill battle...the cleavers don't work well until you are on a plane and in your case 23" is just too much bite.

Seriously...I think 19" props are your best overall prop pitch for your boat. Again..see if some prop shop near you can let you try a pair of used 19" and see how the boat performs the way you use it...then you'll know.

BTW....where are you located?

Kenosha Wisconsin. Was out this weekend, 8 people at 1250lbs, dog out of the hole but planed out again at 54. 14" dia or 15's you think. Thanks for your help. Appreciate it. Still haunt hooked up with any locals to talk to. Would love to hear it at 4500 Rpms. I have tru hall not the silent thunder, which I have heard are better to have, thunder have leaking issues. Just got buff the bow an she'll be like new.

Well, I bought 2 mirage plus 19p... outa the hole like you wouldnt believe,But 3700 rpm max at 51mph.. Now what...checked the gear ratio, 1.47's on both drives...Baffled...any other concerns that will make me puke?

Well...at this point I think it's obvious that your tach is bad. Go to BAMmarine.com ...they are OSO sponser and read through thier data base. Take a look at their top speed calculator. Your boat is probably very responsive and I'm guesing cruises very nicely between 35~45 MPH with plenty of throttle response throughout the speed range. Get yourself a cheap tachometer and hook it up near your helm. Your going to see about 4900~5000 +/- RPM at 51~52 MPH...which is where stock 260's with 1.47 No 1 Alpha's put you in that boat. You are proped correctly.

What I find interesting is that BOTH tachs are bad or for some reason giving you an eroneous reading. There might be a resistor in the tach feed that isn't supposed to be there. I suspect that some one has mistakenly put a resistor wire in the line between the tach and the coil output. I wish you were closer to me and I would hook up with you and help you sort this out.

Maybe some of the other members that have your same boat can shed some light on this for you...don't worry...there isn't anything wrong with your set up . We've just got to figure out why you're getting a screwy tach reading.:eek:

Stay tuned..someone will jump in on this. You might also want to post this info over on the tech forum to draw in a broader audience.

Fivept0, I think I ran across you on lake michigan a few weeks ago I was in Kenosha WI, I was in the red 242 ls with a 271 fastech. Very nice boat if it was you!!! I would also check the tachs you should be able to spin in the upper revs with the 19p. When I had the small block in mine a 19 pitch marige would put me right at 55 mph around 4800-5100 rpm depending on the gear and gas. Give or take a few mph as I didint have a gps at the time.

if you need a original tach to try out, I believe I still have mine some where, from when I upgraded.

That was us. Nice boat!!! I have a couple autometer race tachs that are mechanical, will one work for testing? Also in neutral , I can rev up to 5k, not under load. Maybe I shouldn't be doing that. Lol. I like running the cleaver 23p. Went to an inland lake with em, hit 59.6 on flat water. Met a guy here in town with the exact boat but black n red who is borrowing me some 21 cleavers this weekend. By the way next weekend is the air show in milwaukee We arecruising up together Saturday if your interested.