rebuild i6 1978

[reeldutch]

ok this winter im ready for it.<br />the merc has been laying around for a while and its at the point that i cant stand it any more.<br /><br />the nr 3 cylinder from top to bottem has low comp.<br />about 80 psi.<br />the other 5 perfectly 120.<br /><br />so i have to tear it down.<br /><br />of course i will clean out the carbs and change the waterpump.<br /><br />any advise from the experst where i have to watch for??????<br /><br />thanks<br /><br />reeldutch

 

[Clams Canino]

Re: rebuild i6 1978

If #3 does not have ot be bored .015 over, check it and dispose of aluminum on the sleeve with muriatic acid.<br /><br />Replace all the rings and the endcap seals while you're in there. Lower endcap seals both go lips down and pack grease in between them.<br /><br />-W

 

[reeldutch]

Re: rebuild i6 1978

whats the best way to drop the crank assembly in the block.<br /><br />i only have a workbench. i was thinking of lowering the crank with ropes little by little so i can get the pistons back in.<br /><br />and what could have caused the lower comp in the first place.<br /><br />i have no history from this tower the only thing i know is that it was still running 3 years ago and it has only been used in freshwater.<br /><br />could this motor been lugged???<br />its just weird that it is one cylinder.<br /><br />first i will take the lu of<br />hophely it aint gonna be frozen.<br />how many bolts are there before i forget one?<br /><br />thanks

 

[Chris1956]

Re: rebuild i6 1978

Dutch, Cylinders one and three are most succeptable to overheating and cylinder damage on those inline sixes. Check out cylinder three for scratches and get it bored oversize ($20-30)if necessary. Get a new oversize piston and ring set ($98), and install it. Good luck on your rope idea for reinstalling the pistons. I always end up removing the connecting rod bearings and cages and keeping them in cups marked 1 thru 6. I the stick them onto the connecting rod and crank with grease and then reinstall the connecting rod end. Replace the block base gasket(where block connects to exhaust extension) also.

 

[reeldutch]

Re: rebuild i6 1978

you mean you place the pistons and rods in first,<br />the same as i would do with a evinrude cf V4?<br />than pushing the pistons up to install the rod caps?<br />sounds good to me.<br />better than a whole assembly dropping in and breaking rings.<br /><br />well will see when i get there thanks for the advise<br /><br />dutch

 

[NEECAPRS]

Re: rebuild i6 1978

reeldutch,<br />I do the same as Chris 1956. It's just too easy to get the engine together with at least one cracked ring. One piston at a time preserves the delicate sensitivety to make sure you're not abusing the rings--having one up on a locating pin.<br />As you may well imagine, it's tough accounting for all rollers and not getting the dropsees. But, it's worth it!