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Do I need more positive trim angle?

M.Spectra201

M.Spectra201

New member
Do I need more positive trim angle? I have a 1989 Spectra 201, 89 225 Evinrude. Picked up TCAT’s home customized jack plate, ML-65 built out to 11 ½” setback. This is a good unit, thanks TCAT. The boat could never throw a rooster tail before and even now only when jacked up and at slower speeds. Once the boat gets moving it won’t any more. At WOT, trim full up on smooth water the bow tries to lift out of the water and rpm’s drop but speed won’t increase. Best speed is 64.6 gps trim full up. My best hole shot is to start with trim at almost half way up on guage and trim up from there when I hit the throttle. With trim at that setting for best hole shot, prop shaft is parallel to the pad. Does this sound right? If so do I have unused trim angle that could help the boat run faster but is reduced by the transom angle. The angle between pad and transom is about 106 deg. Above conditions are with plate up, prop shaft 2 - 2 ½” below pad, OMC 24” raker. Also have Renegade 23” 4 blade, same trim for best hole shot but no rooster tails with this one. The motor has 15 deg of trim and I think the first 5 or 6 deg I am not able to use. Would transom wedges be something I should be looking at. T H Marine now have some that offer 5 deg positive trim angle.
Does anyone know this boat or have any thoughts.
I have watched this site off and on for a while now but not posted. Great site, have learned a lot, thanks.
p.s. very busy but will check in when I can.
 
Do I need more positive trim angle? I have a 1989 Spectra 201, 89 225 Evinrude. Picked up TCAT’s home customized jack plate, ML-65 built out to 11 ½” setback. This is a good unit, thanks TCAT. The boat could never throw a rooster tail before and even now only when jacked up and at slower speeds. Once the boat gets moving it won’t any more. At WOT, trim full up on smooth water the bow tries to lift out of the water and rpm’s drop but speed won’t increase. Best speed is 64.6 gps trim full up. My best hole shot is to start with trim at almost half way up on guage and trim up from there when I hit the throttle. With trim at that setting for best hole shot, prop shaft is parallel to the pad. Does this sound right? If so do I have unused trim angle that could help the boat run faster but is reduced by the transom angle. The angle between pad and transom is about 106 deg. Above conditions are with plate up, prop shaft 2 - 2 ½” below pad, OMC 24” raker. Also have Renegade 23” 4 blade, same trim for best hole shot but no rooster tails with this one. The motor has 15 deg of trim and I think the first 5 or 6 deg I am not able to use. Would transom wedges be something I should be looking at. T H Marine now have some that offer 5 deg positive trim angle.
Does anyone know this boat or have any thoughts.
I have watched this site off and on for a while now but not posted. Great site, have learned a lot, thanks.
p.s. very busy but will check in when I can.
 
When you nail the set up the motor will be running just about flat or parralell with the water. Sounds like you need a prop with more bow lift.
 
Your post is a little confusing. Why can't you use 5-6 degrees of trim? Anyway, you don't need wedges. Measure the propshaft height when the motor is hanging straight down. It doesn't matter where it is when it is trimmed. You have thre right amount of setback, if you are not getting lift you may need to lower the motor to allow the prop more bite. The Renegade you should be able to run a little higher by the sounds of things. Don't assume both props will like the same setup, they are very different. Experiment with different engine heights until you find the sweet spots. Finally, 65 mph(gps) is very respectable, don't forget most guys are "overly generous" about their top end speeds.
 
I agree with Mark 65 gps is a very respectable speed with a 16 year old motor . If it pulls good out of the hole and handles well at 60-65 (no chine walk ) your probably real close. The spectra 201 has more dead rise and will be a little slower than a starfight or newer designed hull .My 1989 Spectra 201 with a 2003 225 Opti and 17 inches of setback does 71 mph gps on its best runs (cool temps and sea level ),consistantly 67.7 mph gps.(Two people full fuel and a hot day ) I have enough rpm to run a 26 p tempest plus but prefer a 25p tempest plus.Always compare gps speeds not speedo's. Its amazing how fast some guys boats go until you jump in with your gps .
 
Thanks for your comments guys. I agree that 65 on gps is a respectable speed, it just feels to me that there is a little more in this boat and I am trying to get the most out of it. It will try to chine walk but you can steer thru it.

Mark, Re: your question “why can’t I use 5-6 deg of trim”. Sorry for the confusion, I’ll try and explain better. Motor hanging straight down. I am assuming that means prop shaft parallel to the pad (very bottom of the boat). Is this correct? That is where I measured the prop shaft height.
In order to get to that position (prop shaft parallel to pad) I have to go about 1/3 or more (5-6 deg) up from the bottom of the trim range of the motor. This is the position for my best hole shot and I trim up from there. Does that sound right? Parallel to pad = best hole shot?
So I don’t use the lower 5-6 deg on the trim range. Now I only have about 10 deg of useable trim range instead of 15, thus the reason for my original question.

I have been wondering about this for a while now. Would really appreciate knowing the answers. Thanks
 
Yes, to all your questions. 10 degrees of positive trim is all you need. You actually want to set up your boat so that it doesn't need full trim to get the bow up. Trimming too high will not increase speed because you start pushing the boat down not forward, or the prop just starts slipping. Having said that most Checkmates need at least some positive trim to unwet the bow. Start messing with the prop height to dial it in (watch your water pressure as you go up). Everything else sounds right on the money.
 
Thanks Mark for setting me straight on those issues. Sounds like maybe I have been giving it too much trim because thats what worked best before the j/p. Will try some different settings and see what happens. Sometimes hard to get much of an oppotunity to do that with just two people. Passengers, rough water, boat traffic, wake boarding etc but will definately do this first opportunity. Water press is great, have plugged top two ports and had the plate up high, 15 -20 psig.

Bostoncan, Thanks for your info. Since you are running a similar setup it gives me something to compare to. The numnbers you are getting are about what I expected. My motor is an 89 but had P/H rebuilt late 2001 by a pro from OMC factory and it runs great. Really like the look of your Spectra buy the way.
 
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