Tr 186 boat setup

[KS91306]

Hello all,
I'm new to this site. I currently purchased a 2003 Tr-186 with a 6" Pro High Jacker manual jack plate powered with a 2006 Merc 150 optimax. The boat originally had a 150 XR6 but I had the dealer change the motor to the 06 opti. The prop is a Tempest plus 23p that looks to have been reworked because it's stamped with a DAH>.

Currently at wide open throttle I'm running 5000 RPM's @ 55 MPH. Water pressure is at 14-15 psi. I took some measurements from the bottom of the pad to the center of the prop shaft. I'm at 4 3/4 inches below pad and when I measure from the top of the transom to the bottom of the motor bracket I'm also measuring 4 3/4 inches.

I feel this motor should be running 5600-5750 RPM's and the boat should run 60 MPH. Any suggestions would be greatly appreciated.

Thank you

[jdbarber]

i agree you should be doing 5700 at least at wot. Your prop is too deep. Move it up to 3.5 below pad and try it. Dont let your water pressure fall below 12 psi at WOT. Keep bringing your motor up until your water is 12 psi or you can't leverage the bow up. You need to find out your motors max rpm. Its probably in the 5800 range. Don't go above max rpm or your oil system may fail. Good luck

Jdbarber

[KS91306]

The max rpm is 5750 on this motor. The motor is currently mounted to the jack plate on the top bolt holes of the motor bracket. I think in order to lift the motor any higher I'm going to have to move the bolts to a lower mounting hole. ( hope that makes sense) thank you for the help. I'll keep you posted.

[Michael Stelly]

The max rpm is 5750 on this motor. The motor is currently mounted to the jack plate on the top bolt holes of the motor bracket. I think in order to lift the motor any higher I'm going to have to move the bolts to a lower mounting hole. ( hope that makes sense) thank you for the help. I'll keep you posted.

I am having similar issues with my Astro. I recently moved the motor on the JP and now I have more room to go up as before it was maxed out.

[mdtritn21]

The dealer should have mounted it in the third hole down so you had some movement up or down. I'd call him and ask him to move it up so its set at 3 1/2" in the middle of the plate travel. After getting it moved run it and get some new numbers. Did he put a new water pump kit in it or at least a new impeller.

[dazy_cutter_45]

I dont think the prop is so deep its killing it that bad. I'd suspect motor down on power. My XR6, same boat, will turn a 25 more RPMs than that at 4 1/4" and the 23 at runs 5700ish. Won't hurt to raise it up but methinks the problem lies elsewhere.

[mdtritn21]

Do you see any other numbers on the prop because thats a repair or rebuild stamp. Call DAH propellers (262) 534-4440 and find out what they did to it. It may be pitched up to a 24.

[KS91306]

Will do. Thank you for the help.

[cajunrgfm]

Ya i would figure out what the prop has had done, John is a master at props and it could have a kazillion mods or been changed for a completely different hull design, than yours, It's quite possibly your issue.the 150 opti is a great motor and has alot of advantages over the xr6, and should outperform it.

[KS91306]

I talked with john yesterday. After talking to him about my setup, he said the motor is way to.low. he said rarely does he change a pitch on a prop. I had the dealership raise the motor on the jack plate today. After a few minor adjustments I'm now at 3 1/2 inches below pad. I'm taking the boat out tomorrow for a test run. I'll keep you all posted. Thank you for all the help.

[dazy_cutter_45]

I talked with john yesterday. After talking to him about my setup, he said the motor is way to.low. he said rarely does he change a pitch on a prop. I had the dealership raise the motor on the jack plate today. After a few minor adjustments I'm now at 3 1/2 inches below pad. I'm taking the boat out tomorrow for a test run. I'll keep you all posted. Thank you for all the help.

I'm not feeling thats your problem unless you were way deeper than you figured Good luck, hope that hooks you up

[swolt45]

I had this same problem at one time and come to find out, it was a coil pack that had come unplugged when I put the cowling back on. I know it's a long shot but it can happen. I felt like a complete idiot. v6 outboards run very smoothe and often it's hard to tell if it's missing if only one cylinder is not firing.