86 Merc 150 XR2 powerhead removal

[sawblade723]

Hi, I'm trying to remove the powerhead from my motor but I cant get it to seperate from the midsection. I removed the 10 nuts and washers, installed the lifting eye and picked up on it until the trailer nearly cleared the ground but it did not budge. I tried tapping a screwdriver between the two halves to pry apart but so far nothing has worked and I'm afraid I will damage the gasket surface. Does anyone know a better way to get this to break loose without causing damage?

 

[dbrew]

Re: 86 Merc 150 XR2 powerhead removal

everytime i pull a powerhead i like to drop the lower unit just so the shaft is out of the way. sometimes they can be tough to seperate especially if someone before you puts sylicone or other liquid gasket. good luck

 

[Rscardina]

Re: 86 Merc 150 XR2 powerhead removal

I'm with brew.. taking the lower unit down first is a great idea.. also make sure you take the shift rod bolt out as well... once thats out you can be sure the driveshaft isnt what is causing you to problems..

I just did my evinrude and i had 6 long bolts, 3 in the back and two in the front for a total of 11 bolts.. make sure you have all of the bolts out (im sure you may have already) but just checking.

The manual on that should tell you if you did get all of them...

I also used a sharp chisel along the base to help pry it off..mine split pretty easy..

 

[sawblade723]

Re: 86 Merc 150 XR2 powerhead removal

Thanks for the tip. The manual didn't say anything about the lower unit but I will drop it. I want to change the gasket and water tube seal beneath the block and look for obstructions in the water passage leaving the block.

 

[Rscardina]

Re: 86 Merc 150 XR2 powerhead removal

Just curious...why are you taking the head off?...

 

[sawblade723]

Re: 86 Merc 150 XR2 powerhead removal

The reason I'm taking it off is to try to solve an overheating problem. I have way too much water pressure and it overheats above 1500 RPM's. I was told on here that there may be an obstruction in the water flow leaving the block so here I am.

dbrew, I dropped the lower unit and tried and tried but this thing wont budge. I did see some water leaking out at the gasket area in 1 spot so I guess I broke the seal there. I have got to find a way to get this off now or I will never get it to seal back up. What have I gotten myself into?

 

[Rscardina]

Re: 86 Merc 150 XR2 powerhead removal

I am feeling your pain... i ask myself that every time i do something like this..

Your overheating? ... did you lose the tell tale (peeing water) ?? Your water pump is in good order?...all the basic stuff checked out?? and your still overheating?

I guess it could be a clog or partial restriction but why do you think you are overheating?.. I mean, is your alarm going off? temp reading high?..etc..

I usually check all of the stuff that tells me i am overheating before i actually think I am overheating...especially if i get a good stream of water from the tell tale.. just hope you did the basic check type stuff first before attcking the head..

 

[sawblade723]

Re: 86 Merc 150 XR2 powerhead removal

According to the temp gauge, and it is a new gauge, I run mid way between C and H at idle, when I take off it pegs the needle past H within 30 seconds after take off. Let off to idle and within a minute its back to the midway point. This is with 15 psi water pressure at idle and pegs the needle at 30+ above idle. I have a new water pump (complete, housing, base, gaskets, impeller) a new poppet valve kit was installed, new head gaskets and exhaust chamber gaskets. All water ports were checked while it was apart, all was clear of debris. I wanted to check the adapter plate gaskets but now I dont think I can get the power head off. Everything I try has only caused damage to the soft aluminum and it still wont budge. And to really make things worse now I have a small piece of screwdriver broke off between the block and adapter plate that I cant get out. I wish I could start this day over knowing what I do know I would have left it alone. I really need to get this thing apart but dont know what else to do. I think its MILLER time.

 

[sschefer]

Re: 86 Merc 150 XR2 powerhead removal

Get yourself a few cans of your favorite penetrating oil and squirt it up around the bolts. Every time you walk by it, give it another shot. Do this over at least 24 hours.

Get 4 2" thin blade putty knives and a brick of wooden door shims.

Start a putty knife in on each side with a rubber mallet. Start the second ones on top of the first ones. Finally drive the door shim between the two putty knives.

Keep moving around the block and as it begins to separate add more shims. I've had hangers that didn't let go until I had a 3/4" gap all the way around. Salty's are the worst.

 

[sawblade723]

Re: 86 Merc 150 XR2 powerhead removal

Putty knives and door shims.....hmm that might work. This is a freshwater engine but I can see rust around the bolts. I think its just the bolts rusted in the adapter plate. I think if I can move it a little it will eventually break free. Been hittin it with PB blaster every hour. Now to get those putty knives and door shims. Thanks thats the best idea I've heard yet.

 

[sawblade723]

Re: 86 Merc 150 XR2 powerhead removal

Follow up: After 3 days of spraying PB Blaster, driving putty knives, driving wedges, praying, cussing, yelling at the wife and threatening to burn the whole boat, guess what, the damn thing just pops right off. Thank you all for the advise. This was the hardest thing I have ever done to my boat but with your help, especially sschefer and the wedges idea, I was able to get it done. Thanks again.