Trim and Tab Question....
 

What positions are you trimming out your boats and tabs when running WOT ? My tabs are all the way up in the 3 (as far up as they will go) position on the dash..........is that right or should they go all the way up to 0 ? What position do you guys trim the engines (in a fairly good condition 2 footers) Either I'm trimming it wrong or the boat (engines) has something wrong with it............I was WOT with a few passengers and maybe a half a tank of gas and could only get up to 74mph on the GPS..............from what I've been reading a 29' with Twin 502 EFI's should easily see the 80's. Also the engines are not idling at the same RPM's and when going through my canal at idle and the engines jump up in RPM's at times for no reason when idling in drive. However the boat seems to run really good, I don't hear anything funny and notice any type on power loss .....the water pressure seems to be around 20....oil pressure seems fine around 60psi.......I just want to hear what the Fountain Vets think......should I have the engines looked at or is that what I should expect ? :cool:

Re: Trim and Tab Question....
 

On our 35 Lightning 3.5 is neutral for us and by wot we are at 2 to avoid any friction and 2+ a tick to take out any dancing. Drives have come out to 5 depending on conditions.

Your oil/water pressures are on track.

Re: Trim and Tab Question....
 

At WOT, my tabs are all the way up, and if it's smooth to light chop, I run my drives at 6-7. Feels nice and loose there. :eek: 3.5 is neutral (level with running surface) on mine, too.

I'll only drag one tab slightly to make it fly straight due to wind or current forces. Anything more just slows me down.

The best thing to do is set things up on the trailer. Find your neutral position for both the drives and tabs, then take some red vinyl pinstripe tape and mark your neutral positions next to the arrows on your indicator panels.

This will tell you at a quick glance where things are at, and then adjust from there. RPM vs. speed is the best way to find your sweet spot. The seat of your pants will tell you the rest.

Cheers,
Brian

Re: Trim and Tab Question....
 

I have a 04 29 fever with the 525, its and a xr. I put a drive 1 inch drive spacer on it to help it come on plane and be more responsive aroud the docks. Now that the drive is deeper I dont have to use a much trim to get the bow to lift the prop works now. At wot I run the drives around 3 to 4 on the dash gauges and no tabs unless it is rough. If It gets to rough I trim the drive up more and drag more tabs to help settle the boat.

Terry

Re: Trim and Tab Question....
 

6-7 ARE YOU SERIOUS????? I never trimmed that far......maybe that's why I'm not getting higher speeds.........I don't know..........is that bad on the outdrives???

Re: Trim and Tab Question....
 

Trimming at 6 or 7 is very hard on stock drives/u-joints!!! :eek: I've seen a few drives/u-joints distroyed by over trimming. :rolleyes: You should be able to bring those tabs all the way up to 0 neutral should be between 2-3 mine is just above two. When WOT I'll trim to about 4.5 anything more I start losing speed and boat gets really lose. Check your tabs on the trailer with them all the way up they should have a slight upward angle, hope this helps good luck. :D

Re: Trim and Tab Question....
 

I just bought a 1999 32 fever with 500 EFI s that were rebuilt to accept whipple superchargers (blower pistons, aluminum heads, etc.-I have all the old parts that have only 35 hours on them). These engines dynoed at 790 hp each. This boat will easily run 85. I have only trimmed my drives to "4" anything less drags the engines. I'm have not had the guts to bring the drives up further at WOT. My planes are also read "3" when they are up all the way must be a fountain issue. My biggest issue with the boat is it doesn't want to idle (it kills under 800 rpm) and is hard to dock-I'm going to change the spark plugs-maybe they are loaded up-it seems like the engines are running rich at idle. Otherwise it's a rocket and do those whipples scream!

Re: Trim and Tab Question....
 

Hey, we're back... I wasn't suggesting that 6-7 is where you folks should be running, just saying that's where MY boat performs best. Granted, mine is set up differently most of yours, running Konrad 540 drives and transom assys. On my setup, loose equates to more speed.

At full-out running trim, (6-7) I still have a significant chunk of the "ears" on my transom assys supporting the sides of my drives. I also have drive input shafts and ujoints that are 50% larger than most. My trim cyl pistons are also much fatter than standard Merc, and the lower cases with in-cast nosecones are modeled after racing outboard lowers.

You shouldn't exceed any speed that exceeds what you're comfortable with driving. Even less speed with respect to your passenger's comfort.

But when "testing" with a competent crew, ease into a flight attitude that nets the best speed vs. RPM results. If you feel your behind puckering up, you're close. If it turns warm and gooey, you've gone too far. :eek: :D

Cheers,
Brian

Re: Trim and Tab Question....
 

I keep the tabs completely up & run my trim up to 5-6 - Dago - just keep trimming up until the GPS speed starts to drop - You will figure out the sweet spot in a hurry. I would expect mid to upper 70's with your set up. What props & rpm are your turning? props turning in or out??? non stepped hull correct?

Re: Trim and Tab Question....
 

32 Fever, 502 Mags with stainless marine exhaust , crane cams , 27'' props , 5300 rpm's , tabs 2.5 , drives 4.5 - 5.0 = 83 mph on gps .

Re: Trim and Tab Question....
 

Don't take your tabs all the way up. Find out what tick on your indicator hasyour tabs parallel to the bottom of your hull, and mark your indicator with a Sharpie. Keep your tabs there. Running them up past this will not make you faster.

Re: Trim and Tab Question....
 

I saw you at the cliffs Sat but we were heading out , are you coming down for the 4th . Your boy in the other AT may have gotten offended because I had some things to say about a twit at a local marina , he was one of the people who came to his rescue . Nothing personal though , I would like to see both boats up close , thinking of going a little bigger ...

Re: Trim and Tab Question....
 

That's the thing.........I don't know what props I have! I wish I did know......I'll post a pic if anyone can tell anything from that I doubt it but here it is. I am going to go for a run later today and I can get back to you on the RPM's. Haven't tracked it closely enough yet I guess. We'll see.

Re: Trim and Tab Question....
 

mach props - turning out - I would guess 26p-28p - not the best prop out there, thats what what fountain used that model year boat, newer models used Hydro's - now they come w/Bravo 1's - Dago are you going to Jobbie Nooner? (I would try Hydromotive props for best top speed) good luck.

Re: Trim and Tab Question....
 

I have the Mach props as well , Throttle up figured that I have just over 9% slip which they said was very good ...
Gonna try some Hydros over the winter when I change heads and cams ...p.s. 27's turning in ...

Re: Trim and Tab Question....
 

well I went out by myself...........I had it trimmed to about 5.......in very small waves 1-2ft maybe..........I hit 78mph on the GPS..............the boat runs very well when opened up.........the only thing is my Starboard engine is really driving me nuts now...........it doesn't like to idle at all at starting idle position..(when it does idle it jumps btw 500 and 1500 constantly..up and down, up and down).........drives me nuts when idling through canals and gas docks and worse yet.....now it wants to stall when I put in reverse or in drive and totally screws me up for docking. I don't know if the fuel injectors are dirty or if it's a more serious problem at this point. I know I was at the MacNRays gas station and they only had 89 octane but it seems it was happening before that.........but now it seems worse. I'm pretty sure I should only be putting premium in there. I got all kinds of problems going on. Any suggestions on the engine idling ? Injectors ? ........and I'm sure you guys are only using Premium correct? I had to get the gas I was real low and had to fuel.....I didn't want to after I found out it was 89 but like I said it was that or swim!

Re: Trim and Tab Question....
 

89 Octane is fine, sounds like you have a vacuum leak when an EFI idle jumps around like your describing. You should try posting in the tech section, you will get more response & suggestions. 78 thats more like it, :D

Re: Trim and Tab Question....
 

Which section.......I don't see any "tech section" let me know where I should post it! Thanks.

Re: Trim and Tab Question....
 

sounds like your iac motor is wigging out ....