1989 175 hp Black Max... head gasket help

[Larry Tate]

Hey guys... had my black max out yesterday and the overheat alarm went off. The thing was hot...so I let it cool down for a while. When I started it back up, I noticed it was peeing out of the tell tale no problem, so I started putting back to the boat launch. As I was headed back, the cowl was off and I had noticed a stream of water coming from where the cylinder head and the engine block meet. I'm going to pull off both heads, see what's going on inside and replace the head gasket. Just looking for some advice... first time (properly) replacing a head gasket. Any info on good places to get parts, or common issues/ complications that typically happen would help me out a lot. Thanks in advance guys!

 

[racerone]

Heads will be warped and must be trued up to be flat.---Various techniques to do that at home so ask away if you need to.

 

[Larry Tate]

My buddy used to race dirtbikes and he told me how to put it on a glass table and use like 400 grit sandpaper so I'll do that just to make them flat. Any suggestions where I should get the head gaskets? Kinda lost on that. On a better note, the cylinder walls looked to be in great shape. Also, the head bolts are looking really bad, where can I get a replacement set of these? Thanks racer

 

[Larry Tate]

So I got the heads off no bolts broken...the cylinder walls looked good at first glance also. I was wondering if you could advise where I should get my head gaskets from? Im a bit lost on that. Also, the bolts are not looking good, where can I get replacement head bolts? Thanks for replying racer.

 

[wired247]

You should replace the bolts anyway. The new fasteners from Mercury are grade 8 fasteners but Mercury specifies a torque to yield installation that makes them a one time use deal. 30 lb/ft plus 90 degrees. The part number on the bolts is 10-98534 and they run about a buck fifty each. The gaskets you need are merc number 27-41246-1.

Prices depend on who you buy them from. Those part numbers and google will tell you everything you need to know. I'd stick with genuine Mercury gaskets if you can. FWIW its less than $90 to get the heads surfaced and have the chamber size set where you want it.

 

[sam am I]

Might want to deck the block too!! Mine was a little out, you might have too sounds!! Over heating can make things worse too, depending on how far overheated of course. Can't hurt to check at least, I probably could have gotten away with not but did anyway. Your block is aged a bit and you could be headed right back to leaks down (or the near) the road if its in need. Typically they're a few thousands off by now under normal use, you could be more then a few, perhaps many fews.

Edit.......Oooops, guess you're not taking it down all the way, nevermind.:sleeping: But, I guess then this would be an FYI at this point when and if ya get there......GL

 

[Larry Tate]

Thanks for the replies guys...the part numbers will help a bunch. A local place told me $150 for both heads so I figured doing it myself would be a big help, and my buddy kinda told me it's no big deal...is this true? What is chamber size and the benefits of setting it? Also, how should I prep the engine block for re install? I'm assuming no razors or anything metal to take off the remaining gasket pieces?

 

[wired247]

With a 2.4 liter you can knock the chambers down to 32 cc , run premium gas and gain a huge boost in low end and mid range and even better mileage if you can keep your foot out of it. Rucks machine will cut both heads for $60 plus the round trip.

 

[Dukedog]

My buddy used to race dirtbikes and he told me how to put it on a glass table and use like 400 grit sandpaper so I'll do that just to make them flat.

Eat ya Wheaties and a coupla cans of spinach might help............before ya start!

 

[Larry Tate]

ok so my bolts and gasket came in today. Now I just need to know how to prep the engine block itself for re install? Also, should I use any type of gasket sealant on this? Any tips and advice much appreciated, this is my first 2 cycle outboard head gasket.

 

[wired247]

Dont use sealant. 30 ft lbs and 90 degrees on the bolts.

 

[Larry Tate]

Ok I'll put then on dry then. Thanks wired. Can u maybe shoot me a link where I can find part numbers for thermostats and spark plugs for this beast? Thanks