Motor mounting Height - Huge Difference -

[Skoot]

Not much to report, unfortunately. Raising her 1/last hole didn't do too much.  Also, the testing conditions were not the greatest. Stiff onshore winds, 1/2' chop and tons of boat wakes in the inter-coastal. Im guessing she gained about 100rmps by raising her to the last hole.  Im gonna try to get to the lake during the week for a better test.

The good thing is she's mounted correctly now. The anti-cav plate is just skimming on top of the water.

All in all Im still thrilled.  I went from 4200 @ WOT to currently 5000-5100rmps @ WOT.

[gran398]

Hey, glad you're back. How much speed did you gain?

[fitz73222]

Hey Skoot,
Now that you have the engine at the height were she is going to stay. Take her off one more time and clean everything in the mounting hole areas and completely reseal the bolt holes and mounting flanges and reinstall the engine to make sure no water enters that transom.

[Mike453]

This may sound stupid, but do you need to fill the space between the motor bracket and the transom, when you raise the motor?

[seabob4]

This may sound stupid, but do you need to fill the space between the motor bracket and the transom, when you raise the motor?

Mike,
Do you mean the little gap at the top of the transom where the transom trim is?

[Mike453]

Yes seabob, if I go up 3 holes there would be a larger space.

[seabob4]

Yes seabob, if I go up 3 holes there would be a larger space.

The absolute "proper" way to do it is to mark the trim where the engine mounting plate hits the trim, yank the motor off, remove the transom trim, notch it at the marks, reinstall trim, re-hang motor...

[GoneFission]

You do not need to fill the space between the motor bracket and the top of the transom.  The transom through-bolts are adequate structural support for the motor.  But do make sure it's a sealed with 5200.  

[aquaprouts]

What year is the merc 200? I just bought a 196 aquasp with a 1993 merc 150 efi(looks very similar to yours)....runs stong and only roughly 400 hrs of mostly freshwater usage....what do you know about these outboards....anything i should be aware of.....i have heard the like to drink large amounts of fuel and oil...what is your experience?  Thanks.....capt kurt

[wingtime]

Wow  Old thread...  I forgot about it to tell you the truth.   The 200 Merc was kind of a "FrankenMerc"  I think it started out as a 91 or 93.  It had a 1998 factory power head on it.  It was sold to me as a 25" motor but it turned out to be a 20".  So I swapped out the midsection with a 2001 mid section and mount.   I think I ended up moving it up a few holes and going to a 17" pitch prop.  That ended up giving me 42 MPH at 5600 RPM WOT.   Keep in mind the 200XF had the CCP hull which has a MUCH deeper entry than your 19'6" does so it takes more power to push her fast.  The 150 Merc should push your 19'6" pretty darn good.  Mine was a carburated model.  Actually she wasnt THAT thirsty.  My 225 Ocean Pro burns MUCH more fuel if you ask me.  Fitz is the authority on the Mercs but I can tell you they are reliable motors.  I'd run Non-ethanol in her if you can get it.  Change out the T-stats, Poppet valve, impeller, fuel filters, and plugs.  I'm not sure if there is anything you should do to the fuel injection such as the VST etc.  Like I said Farley (Fitz) knows much more than I do.

[GoneFission]

What year is the merc 200? I just bought a 196 aquasp with a 1993 merc 150 efi(looks very similar to yours)....runs stong and only roughly 400 hrs of mostly freshwater usage....what do you know about these outboards....anything i should be aware of.....i have heard the like to drink large amounts of fuel and oil...what is your experience?  Thanks.....capt kurt

If memory serves me right, the 1993 Mercury 150EFI is an early 2.5 liter V-6 with the single point injection system.  These engines are not fuel/oil thirsty - the EFI uses about 20% less fuel overall than a carb model, and it has the Mercury auto oil injection systems that is very reliable and meters oil based on throttle settings.  The biggest issues are the same as any other motor - corrosion on electronic/electrical connections, quality of fuel and oil used, use of ethanol fuels, water seepage into the lower unit/gearcase, and overall care and maintenance.  The 2.5 liter 150 is a bit undertuned, and most actually put out more than 160 HP.  

As an oddball, there is an outside chance you could have a 2.0 liter 150 that was a leftover from previous years - but that would be unlikely.  The key to any Merc engine is not the year, but the serial number.  Everything about these motors is tied to the serial number, not to the model year.  Changes were made in the middle of the model year, so the model year may not fully represent the actual motor.  

The 2.5 liter Mercury 150 is a very strong running engine for a 150, probably because it put out closer to 160 HP at the propshaft at around 5000 RPM.  You should work to prop this motor for about 5300 RPM at wide open throttle.

[Curious]

Hope you don't mind if I hijack or at least continue this thread.  Here's my issue:

When I rebuilt my transom I saved the exact bolt pattern and was able to use the existing holes to through bolt and prevent the two fiberglass transom skins from bowing out while I poured the Nidacore pourable transom compound.  Anyways, when I installed my motor, the lower bolt holes are bottomed out on the motor mount, preventing me from being able to go any higher without re-drilling new holes.  The motor is definitely too low and needs to come up.  So I have two questions-  1.  What is the best way to drill new holes?  Take the motor all the way off or try to drill new holes with the motor in place?  2.  Can I just fill the old ones completely with 5200 or should I fill, reglass, etc.  The new transom being Nidacore I'm not too worried about water intrusion but still want to do it right.

[fitz73222]

Dan,
I personally hate drilling extra holes in any transom if I don't have to. You can transfer another higher set of holes from the engine mounting bracket to allow you to raise it or I would strongly consider a manual adjustable jack plate that will bolt into your existing transom hole pattern and will give you the ability to really fine tune your engine height up to 5 inches without having to unbolt to raise the engine each time. With the exception of my 22-2, I've had jack plates on every boat I've owned. Bob's Machine in Ruskin, FL makes a nice one. I think you would like having one!

[wingtime]

Dan,
I personally hate drilling extra holes in any transom if I don't have to. You can transfer another higher set of holes from the engine mounting bracket to allow you to raise it or I would strongly consider a manual adjustable jack plate that will bolt into your existing transom hole pattern and will give you the ability to really fine tune your engine height up to 5 inches without having to unbolt to raise the engine each time. With the exception of my 22-2, I've had jack plates on every boat I've owned. Bob's Machine in Ruskin, FL makes a nice one. I think you would like having one!

I have a Bob's machine manual jack plate on my 170.  I love it.  The engine is riding at a perfect height and it sets the engine back several inches giving me more room in the back of the boat.

[Curious]

Hadn't thought about that option, glad you mentioned it.  Looks like around $280 if I'm looking at the right one.  Do you guys have any pics of yours?  Does the setback change the way the boat rides/gets on plane?  I guess it can't be much different than an Armstrong type bracket, I guess.