RPM's and Trim

[88 Enchanter]

Had the boat out this weekend and have a question to run by you all! When I am at full speed trim all the way down and try to trim the boat up, it seems to kill the RPM's, but when trimming up while accelerating does not act the same way. Can anyone explain why it does this or is there something wrong with the way the boat is acting. It is a 21' Enchanter with a Merc 260 I/O will run about 65 trimmed out! Any insight is greatly appreciated! Thanks in advance!
tstone3@aol.com

1988 21' Checkmate Enchanter
"Simply Gorgeous"

 

[happy]

why in the world would you trim all the way in at wot???? I think your boat responded as expected... and i would also reccomend not trimming all the way in at wot... you hit a wave wrong and you'll stuff your boat!!

when you trim in, your pushing your bow down increasing the wetted surface of the hull, increasing drag.. trimming out lifts the bow, reduces wetted surface and drag, increasing speed and rpm..

during my normal course of work, i run a variety of boats, and all different horsepower.. as a personal preference... i only use tabs to stabalize the vessel, never to assist on helping the boat plane.... i start w/ tabs up, drives full down, throttle to about 2500 - 3000 and then begin trimming.... once the vessel stabalizes, i then pin the throttles, stabalize w tabs, and fine tune my trim..

 

[88 Enchanter]

Happy:
I don't think you understood me correctly. Let me try and rephrase this again..... When I take off in the boat from a dead stop and once boat planes out, when I start trimming the boat up, the motor will bog until I back off of the trim. The boat will run top speed right near half trim but to get there the motor will bog as I am trimming it up until I let off the trim switch. Is this normal or am I doing something wrong? Any help or insight would be greatly appreciated. The boat with a 19 pitch quicksilver is running mid 60's with 4-6 people in the boat at about 5,200 rpm's on the guage, not too sure how accurate the rpm's are but the speedo is pretty accurate on my GPS. Thanks again in advance!!!

 

[daren34]

eluder

check the wiring to the trim pump

should be direct to the battery

if that is ok then look at the alt or battery (dead cell)

when you are trimming the voltage is dropping to the ignition coil

good luck daren

 

[CheckmateFever]

I've never noticed that with mine before, but i will say it is very responsive trim. I know i'm a little of topic here but i noticed you said you're running a 19 pitch prop and gettin in the mid 60's...i'm running a 23p prop but i don't know how fast i'm goin (low 60's i figured)...motors only turning about 4300 rpms (actually only 4100 this year for some reason, haven't figured out the rpm loss yet other than the timming was messed with at the beging of the season but i don't think my tach is very accurate either, motor seems to be running very good) 5200 rpm's seem kinda high, is your engine stock? I'm trying to research different props so i can re-prop mine and get the best performance out of it.

 

[hydroslide]

when you are trimming the voltage is dropping to the ignition coil

good luck daren

Thats exactly what it sounds like behind the boat, like its dropping a cylinder or 2...Did you dry out yet?????

 

[happy]

back in those days 4 to 4400 was top.. rpm.. always remember .... who has the best day out.. and its not the fastest. its the consistet one who wins every time... this is a fair statement... you can't win if you dont run, and you can't win if you don' t run every time.. but you can win just by running.. let the big boys go... and i assure you they will break... take your kids and let them see what boating is all about.. please, let your family know the beauty of boating.. you don't need to be the badest boat on the lake.. you just need to come home after a family day... and your moto still moto..

the best thing about this.. is.... you win .. all the way around.. <<< thanks...

happy...