TurbosRfun

454/330HP, Bravo 1 with 23P Mirage 3-blade
~430 hours on the boat

OK... let's hope it's not the bottom of the boat deflecting! The boat had a survey earlier this year and it didn't show anything like that. How exactly do I "sound" the bottom of the boat, just knock on it with something?

Some people are suggesting that I may have possibly "blown out the hub for your prop" and are asking if I have a solid hub prop or not, and honestly I don't know? I don't even know how to tell (yet). I have a 19P cleaver that I could throw on there, but that's not exactly a fair comparison.

Dumb question but... Could having both of the trim tabs "down" all of the way into the water make the boat perform that badly??? When I pulled it out of the water last time, I noticed that I had my trim tabs extended all of the way into the water. I thought I had raised them up all of the way, but they move the opposite way that I thought they did. OK... I'm stupid-new to this obviously, but could this be it?




-=Mike G.

MOBILEMERCMAN

Yes, Mike tabs all the way down could be the problem. On your prop if you look in the hub is the center area close to the size of the shaft or is it much bigger in diameter. You can remove it and look at the back side to see if it has a hub or not. The 19 cleaver would turn about 800 more rpm's then your mirage and wont slip if you try it. I hope the tabs fooled you and your home free.
Jim

BURNSMAZZ

Fill that trim tab reservoir up (you problably have a leak) figure out how to operate your tabs correctly as well as the trimming of your outdrive and go back out and try it.I can't believe it's something that serious.Does the motor sound like it's running properly.It looks like you are out on St. Clair,are you sure you didn't hit bottom or anything that may have caused damage to the prop or drive?

Griff

Yes, the tabs being full down will do exactly what you said happened. I'm 99% sure this is what caused your speed loss.

TurbosRfun

Nope... definitly didn't hit anything. I've only run the boat 4 times, and every time I've gone from Metro beach staying between the markers out to the South Channel following the markers in. Basically right in the middle of the lake. Stop at Gull Island for a while and head back via the S. channel cutoff. I did idle it with the drive down at kicked up some sand once so far (parking at Gull), but that's it... about 2-2.5 feet on the Depth finder.

The motor sounds good to me. Takes a couple of tries to get it started initially, sputters for the first couple seconds, but after the first start of the weekend she's good to go. No missing or anything that I can tell. Just tuned up (plugs, wires, cap, rotor). I haven't removed the air cleaner cover to see what's going on there yet. Power seems good as can turn about 4000RPMs out of the hole if I really wanted to with almost full throttle, and again I don't think my issues are power related as cruise RPM of 3000 is obtained, just without the speed of cruise.

If the trim tabs are the problem, I'll at least be happy while feeling like an idiot. I had a 21' Bayliner Cuddy on St. Clair before for a few years, but it didn't have trim tabs on it. I'm familier with trimming the drive up and down, and know what a cavitating prop feels like. There is a definite sweet spot for drive trim on this boat, and it's different at full speed than at cruise for sure.

I'm gonna fill it up, raise the trim tabs all of the way up and take it out today and see what's up. I'll post back with results.

THANKYOU soooo much for all of your responses so far. Hopefully you all don't feel like your wasting your time here. I guess we'll see after todays test drive. If any of you see me out on the lake, you are entitled to at least one of my beers for your help.

I'll update later tonight,

-=Mike

kennyo

A spun hub or prop will increase rpm and lower speeds. I vote for tabs!

THLWL

If your only problems are the tabs are down, then you're the luckiest boater I've ever heard of!!!!!!!!!!!!!

TurbosRfun

TABS DOWN WAS THE PROBLEM!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! I am SOOO freakin' excited! The boat is "flying" once again!! (at least to me)

Just went out... 67mph on the speedo in Anchor Bay, and ~64mpg on the speedo in the middle of the southern half of St. Clair with maybe 2 foot chop out there!!! It feels like the entire boat was out of the water most of the time! (yes I know it just feels that way).

YYYYYYEEEEEAAAAAAAAAAYYYYYY!

Thanks again for everyone's help 110%! Chalk this one up to an idiot with an offshore boat. I cannot express in words how excited and relieved I am...

-=Mike G.

point92mach

Man, I'm going to go and check the parking brake on my BMW..... If it worked for you, it might work for me!



Greg

Payton

Congrats!!

Now take a level, level your boat on the trailer with the tongue jack, next place it on your tabs, make them as level as you can. Then put a mark beside your indicator. Do the same for your drives. a Magic Marker, touch up paint of a small peice of trim tape works well. That will help you to know where your drives and tabs are. Your tabs should be level with the bottom or just slightly up under average conditions.