MDonziM

After a largely successful season, had a pretty bad ending when I blew up both lower units on an "Around Manhattan Fun Run". Kicked a hole in the side of my LH aftermarket lower and an hr later seized a bearing in the RH while limping home. No power in the Harlem River of all places. Not exactly how I imagined the day going... Seems that both lowers lost some seal(s) and basically ran a Sahara no oil test until something failed. So, I had planned on taking the boat south to key west which I had to scrap.
Plan now is to rebuild the RH lower which is a Torque-master and get a new LH Torque-master by springtime.

Went to post a pic from the fall but I guess my membership expired, I'll renew and post.

PG-13

MDonziM I read you were having issues with water pressure on previous post. Now you had lost your drive oil. Check your lowers for overheating thru the exhaust. I've had this happen on a 8m Carrera with twin 250. Once the boat started attaining high speeds in conjunction with engines set high started the night mare. The lowers did not have the front low water pickup. We installed a kit that Merc has to increase water flow and we blocked of the top two water ports with set screws. We chased this thru water pumps, gaskets, water pressure regulator, thermostats and cleaned out the mid section ( recommend you do this as salt will have built up in exhaust do to overheating) It will also cook you lower unit seals. Due to your lower units so high when you turn the boat right or left the outside motor losses water flow. We resolved this by finally getting some torque master units and converting the splines on the shaft to mate with the 250 efi's After that all problems went away. Hope this helps. We also ran labbed B1 26p props. Your porpoise problem is probably coming from having engines so far back. Bracket and jack plates are putting props to far. We also tried and then removed the jack plates.

ModeratedUser02102018

oh no....sorry to hear about the reak down
well the winter is always a good time for stuff to break down..
i c the weather in the north is a little snowy.....

question...
how much set back do u have on the midnight..?
do u think that the gas tank placement has something to do with the porpoise?

MDonziM

Thanks for the info. Yes I blocked off the top 5 water intake holes on the inboard side and 4 on the outboard side of the lowers. I did also have low water pickups but only had 8lbs of pressure. Water temp was ok I think, the engines are not raised aggressively. The setback is 26" bracket and 3" jackplate. The tanks are the original position from when the boat had inboard/ arneson drives so the center of gravity has certainly changed.

PG-13

Give me some info. When you throttle up to get on plane does it jump up or does it lag. does the bow go up a lot or slightly. When you are running what is the angle of the boat ride. Is it slight bow lift, flat or bow down some. Tabs where do you have them set. do you use them to get on plane does it help or hinder. I don't remember did you check the water pressure valve/ regulator on base of the engine midsection. A lot of little variables. But do check exhaust in mid section. It most likely coated with salt and clogged up by now. This is due to your lower unit seals being compromised.

MDonziM

The boat planes out pretty easily with no tabs needed. There is a small lag but its slightly over propped with 24" bravos that are not vented. When cruising I run a little tab to stop porpoising but that goes away mostly with more speed. The boat wants to fly a bit in choppy water or bigger seas especially compared to my I/O boat. Not sure still about the water pressure, the motor height was not that aggressive ( maybe 3/4"-1" above the bottom) Had the popper valves checked and running standard 143 deg thermostats, water temp seems fine. I'll find out more again in the spring when I get the one lower rebuilt and get a new counter rotating torque-master for the other.

PG-13

Try a prop that is vented to resolve the planning lag. The temp of the motor wont suffer. But if you are losing water pressure it will be insufficient to cool the exhaust. Causing salt to build up in the exhaust stack and thus cooking lower unit seals. If you have the lower units off. Tilt the engines up all the way. Get a flash light and look up into the midsection. You should see the exhaust canister can. It should have a series of holes for the water and exhaust to go thru. All holes should be open. Takes only 5 minutes.

MDonziM

Hmm, thanks, I'll look into that.

MDonziM

Looking forward to warmer times again...

scippy

Marshall.......Just beached there, that 32' hull design looks timeless - you did a wonderful job on the restoration.....did you ever talk to Phil about the faulty fuel tank?
My Mistress is also and '82 and is in remarkable shape for its age ..........would love to see you out on the ocean this upcoming season!