Proper height for transom plate on Black Max 135.

issachar

Cadet
Joined
May 11, 2007
Messages
28
I have bought a Procraft 170 fish and ski. It has a Black Max 135 on it. The owner before has moved the transom plate at least three times based on the different holes he used(it has five available). It currently seems high to me. A gentleman at the lake confirmed this to me the other day, but I am unsure if it matters in real terms. At most it may be 2-2.5 inches high. Can someone explain to me the effects of a lower or higher setting, especially as it pertains to lower speed hole shot type behavior.
 

Barnacle_Bill

Admiral
Joined
Feb 8, 2004
Messages
6,469
Re: Proper height for transom plate on Black Max 135.

Sounds like they were trying to get more speed out of it. Hope the have a water pressure gauge on it.
 

issachar

Cadet
Joined
May 11, 2007
Messages
28
Re: Proper height for transom plate on Black Max 135.

So the question is what do I loose if I put it back down?


It does have a temp gauge and it doesn't overheat so far.
 

redjmp

Chief Petty Officer
Joined
Mar 16, 2005
Messages
536
Re: Proper height for transom plate on Black Max 135.

You loose speed the lower down you put the leg. Less drag = more top end.
If you are not sucking air and your prop does not cavitate when accelerating then you are fine the way it is. Sounds like the previous owner spent some time getting it right.
 

issachar

Cadet
Joined
May 11, 2007
Messages
28
Re: Proper height for transom plate on Black Max 135.

It seems to run fine after the initial throttle drop, but it just seems off for a split second at first. Kinda hard to explain but it really runs good through most of the range. I don't know. Just trying to figure out whats missing. It seems that the motor ought to be plenty for that boat and feels like it is strong enough, just something seems out a little. It's a feel more than an obvious symptom. I thought maybe it might be a slight bit to high but I guess not. Thanks for the input.
 

redjmp

Chief Petty Officer
Joined
Mar 16, 2005
Messages
536
Re: Proper height for transom plate on Black Max 135.

If it feels like it wants to stumble during holeshot, that is usually a sign of not enough gas. Might want to try backing out the idle screws 1/4 turn and see if that helps. Might be time to open up the carbs and clean them out.
Does it get to WOT? Should be around 5500 I think. With a 17p prop that should equate to about 45mph
 

issachar

Cadet
Joined
May 11, 2007
Messages
28
Re: Proper height for transom plate on Black Max 135.

I believe it tops out in the 5100-5300 range. I know I should have checked but I have only been out in it a twice since I bought it and I have a lot to get used to. I have been a inboard man up to now so it is a little different. My prop is a 21 pitch just fyi.


thanks for all your help.
 

yorkserv

Seaman
Joined
Apr 14, 2005
Messages
52
Re: Proper height for transom plate on Black Max 135.

I ran into the same questions as you when i bought my boat i have a 20' make with a 200 black max and right out of the whole its seem like its not all there but its like you say not a symptom but a feeling i really just messed around with the trim on the motor to be able to get it out of the whole smoother
 

dtherrien

Petty Officer 1st Class
Joined
Jun 9, 2005
Messages
213
Re: Proper height for transom plate on Black Max 135.

First thing you need to do is a tune up , new water pump and a sync and link. you want to make sure your motor is running perfect.
Then on the water make some WOT runs, adjusting your trim through out its range. When the prop breaks loose,lower it back down. If you cant use at least half of you trim range before the prop breaks loose....then your motor is to high. Your peak rpm should be about 5500-5600 with a normal load and not from breaking loose.
If everything checks out ok and your rpm is still low, you have to much pitch on the prop.
 

issachar

Cadet
Joined
May 11, 2007
Messages
28
Re: Proper height for transom plate on Black Max 135.

Well I changed out the plugs myself and the impeller was new last year.
Syn and link? Not sure exactly what you mean there. As I said before, totally new to outbaords. I had the inboard stuff down, but this is new to me.

One new fact to add. As if I needed more confusing multiple issues:) . I took it out today on a small "no wake" fishing lake close by. It died three different times idling along. I had to rev it up and clear it out to get it to idle, but it still didn't like the slow pace. I know some say these can load up when they don't get to run higher rpms for extended periods. Should I be worried. I am wondering if it is possible the carbs might be overdoing it a bit and that is causing a slight delay in my hole shot. Anyways thanks everyone for the helpful thoughts.
 
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