Trim Q - Maxum Boat Owners Club

Argonaut · 07-27-2008, 06:49 PM

I always start with trim right down. (1800 SR3 with 4.3L)

This puts the trim indicator below the bottom line on the gauge.

So far have been only able to apply the tinniest amount of trim before it s starts porposing, gauge just about move the needle to bottom pair of lines.

Is this normal on a Maxum ? ......
Previous boat I was used to being to trim out well as soon as on plane, and it would be a fair degree of trim before porposing started.

I am also getting a huge amount of hull climb when starting off when towing a skier, so much so that if I were to be seated I would not be able to see anything in front on me other than sky !
maybe it is just that 1800 is underpowered compared to what I was used to ( my previous rig weighed 60% less and had a 200hp outboard) it could pop skiers up on water effortlessly - and never any bow climb.

Overfinch · 07-28-2008, 12:14 AM

I do recognise what you are talking about here but not to that extent. I usually find that the flatter the water the more trim can be applied without porpoising, I managed to use just about all the trim during performance testing in Torbay last week. On that subject how are you getting on with your High Five?

Argonaut · 07-28-2008, 10:02 AM

High Five is good ... but overall finding Maxum seriously lacking low end power ... it gets to top end no problem, but is lacking in low end pull.
Compared it to 3 blade prop and High 5 is better - but still not as much as I'd like.
Not tried using the tuning plugs yet - maybe they will help.

Having to use a lot more technique to get out of water up on Ski ... maxum can't 'pop you up' it just drags you like an anchor.

Severe bow rise as well ... I have to stand up or I lose all sight of what is in front on me on a start.
What is your minimum planing speed ? ...... I can't keep it on plane below 20mph which is a pain for kneebaording for the kids - means I'm ploughing through water rather than on it.

The Chevvy V6 must have been tuned & tweaked thousands of times in US, maybe I'll do some looking out of season see if I can gain 20hp or so.

Overfinch · 07-28-2008, 11:51 AM

I don't have the excessive bow rise and the boat 1900sr2 planes quickly and so it should with 260bhp but I do try and keep as much weight forward as possible. However I have the same issue with planing speed 20mph is as slow as I can go and stay on the plane, I had wondered about the smart tabs to address this issue.
I am using a turning point ss prop 21 pitch and this has small drilled vent holes. I can only compare it with the standard 23 pitch ali and the difference is very significant lost probably 1mph off top end and better hole shot. With a normal load max rpm is 4850 and with just me about 4975rpm. I would like try a 19 high five but thought it might over rev at top end.

Gazjen · 07-28-2008, 05:27 PM

I've got hydrafoils on this boat even though I've not had this one in the water I've had them on my previous outboards and they really make a difference up on plane quicker and let you plane slower. very cheap to try out too. but the smart tabs look good been looking at them myself

If I really get into this boat I'm going to supercharge this engine having just rebuilt it I know it will be fine that should give 50-60hp fairly easily

BayBoy · 08-04-2008, 05:36 PM

The next time you have it out of the water you may want to check the calibration on the trim indicators. What you see on the gauge may not accuratly represent the actual location of the drives. You need to trim the drives all the way down then, with ignition on, loosen the trim indicator on the side of the drive an have someone watch the gauge. Tune the indicator switch slowly and as soon as the needle on the gauge lines up with the bottom indicator line, lock the trim indicator down tight and then repeat for the other drive if you have more than one. While you are at it, check the limit switch as well. There is a predefined distance between the centerline of the mounting bolts of the trim cylinders must be set to (varies between Alpha and Bravo). Bravo drives is 22 3/4". Make sure your limit switch kick out the drive pump when you reach this distance. This prevents over trimming the drive while under power as you can damage the u-joint and/or raise the water pick up out of the water and cause an overheat condition. If the limit switch is set correctly the trim gauge should stop on the center mark when the limit switch kick in. It should point to the upper mark when you overide the limit switch with the trailer switch.

Brit Rider · 08-04-2008, 05:50 PM

THe 1800SR3 hull handles like a bathtub at slow speeds. Rest assured what you're experiencing is perfectly normal.....

Mines exactly the same. and if you turn to quick you can bring water in over the side.... great boat! :shock:

:twisted:

racer2c · 08-05-2008, 03:16 AM

Buy a ski boat.

Brit Rider · 08-05-2008, 06:16 PM

I did

racer2c · 08-06-2008, 02:50 AM

Quote:

Originally Posted by Brit Rider

I did

That was to the thread starter.

My 190hp must use bigger horses than the EU versions. I have a stock prop (23') and can pop a 180lb male up on a wakeboard with four adults in the boat all day long. That thing to the right of the seat is called the 'throttle'...nail it.
Ease into it and you'll only see sky. Your 'boarder needs to know how to get up too, not just rely on the boat. It takes two to tango. A human anchor can dog most runabouts.

Argonaut · 08-07-2008, 07:40 PM

Quote:

Originally Posted by BayBoy

The next time you have it out of the water you may want to check the calibration on the trim indicators. What you see on the gauge may not accuratly represent the actual location of the drives. You need to trim the drives all the way down then, with ignition on, loosen the trim indicator on the side of the drive an have someone watch the gauge. Tune the indicator switch slowly and as soon as the needle on the gauge lines up with the bottom indicator line, lock the trim indicator down tight and then repeat for the other drive if you have more than one. .

anybody got any pictures or links so I can easily identify the trim indicator? it's an Alpha One

Argonaut · 08-07-2008, 07:42 PM

popping up a wakeboard is easy .. popping up a monski with a 225Lb guy attached is not so easy.

Brit Rider · 08-07-2008, 10:05 PM

Racer - Funny thing is that my boat runs on 96-99octane fuel also, whereas yours is about 86 in the US? I've also got the MPI so another 30HP... not that I've noticed any diff between the 2 engines///

I nail the throttle but its still no comparison to a tournament boat.. but then again, the Maxum ain't supposed to be and its a hell of a lot easier to look after and far less $$$$...