Re: 76 mercury 1150
Against my better judgement.......<br /><br />I'll post a "last ditch" save for an old worn inline. I want to NOTE that I do NOT (and will not)do this on powerheads I sell, PERIOD. OK?<br /><br />I have done it for a couple customer motors (at thier request) to extend a poor situation into something livable. If you have more time than money, this might keep you wet till you can fix it right.<br /><br />The following also assumes that the cylinders are not too far out of round:<br /><br />Enough disclaimers??<br /><br />OK, the standard bore is 2.875. A .015 oversize bore is done to 2.890 <br /><br />If your bores at worst point are 2.880 (total wear .005) or less you'll benifit to some degree from re-ringing all six to "extend" a bad situation a while.<br /><br />Anything over that and you really have to bore all six .015 over and get new pistons. If you use aftermarket pistons and a good machine shop you'll spend $700 - $800 to do this.<br /><br />Don't wanna put that kind of cash into something that old? Want time to save some money. Try this.<br /><br />Use a flex hone on all six holes and get 6 sets of .015 oversize rings. File each ring (evenly on both sides) so that you get about a .003 - .005 end gap at the widest point in its cylinder. Check to make sure they don't bind at the narrow area!<br /><br />Leave any and all carbon on the pistons EXCEPT in the ring grooves, this to help the pistons fill those worn holes. An alternative is to have the pistons "shot peened" to make them "grow" a bit.<br /><br />Reassemble as per normal, hand turn several revolutions to make sure nothing is binding and then "pre-break in" with a double oil mix in the driveway at a slightly fast idle for a good hour on the muffs. Then take it to the water and continue break in for a good ten gallons varying loads and avoiding WOT. <br /><br />Lastly, run it at a 40/1 mix, Use Power Tune twice a season as directed. Remember to warm it up fully before you hammer it too, you want those poor old pistons to expand as much as they can. Now, start buying a piston a month like a Christmas Club.
<br /><br />The downside to doing this is that the oversize rings will tend to put a bit more pressure on the bores and cause a bit of premature wear. However this is mitigated by the fact that the bores are already too big, lessening that same pressure. Once you break it in, and the bores are like glass again, the 40/1 mix will help mitigate the issue.<br /><br />You'll easily get a season or few this way... and the best part is, when it's time (financially) to bore out to 2.890 all the way around, no harm has been done in the long run.<br /><br />Is this a long term repair? - no. Will it get you back on the water for under $100 while you budget for other options, yep!<br /><br />-W
