my 80 hp merc died today

i have no idea what happened, or why it happened. i was cruising around and my 79 merc 80 started to stumble, so i shut it down and checked the fuel. tank 1 was about empty, so i switched tanks to the full one. shortly after, it started running really rough, so i stopped it again and it shot steam out the tattle tale hole, and could find nothing wrong, it didnt get hot and everything looked good. so i started it up again and it had NO POWER. it started knocking for about 2 sec, then it stopped so i kept cruising. but it still had no power and would die if it was anywhere close to idle. at wot i was cruising about 14 just bairly on plane. i finally made it to the ramp, pulled out and got home. i pulled out all 4 plugs and i have no compression in cylinder 1, all the others seem fine. am i screwed? or can i rebuild for a fair price?? i have good mechanical skills for the most part, rebuilt auto engines, built cars but have no ideas about 2 strokes other than theary. any hints, ideas? im so depressed right now, my boat is my only release from the stresses of reality.

Re: my 80 hp merc died today

Man, sorry for your troubles.

I'd say your next step is a good manual and a tear down for inspection. Some things can be replaced. I will say its a good sign that you dont have a rod sticking out the side.

Re: my 80 hp merc died today

I feel your troubles. My 90hp threw a rod bearing and left me with a $2000.00 problem. Well worth the money to get it going again. I hope yours is better than mine was.

Re: my 80 hp merc died today

Kartman, You need to decide if you want to spend the money to fix it. if you do the work yourself, and the damage is limite to #1 cyinder, it will cost about $200-$350 to fix. Other damage will cost more.

The second thing you need to do it to figure out what caused the damage. It is likely that the top carb ran lean causing detonation or the motor ran hot. You need to rebuild both carbs, and replace the waterpump impeller. This runs under $100 if you do it yourself.

Re: my 80 hp merc died today

i ordered the manual, is their a better one than the seloc? also i think im just going to replace all the pistons if the block is boreable. cant wait to get into it. it looks like its a simple engine, kinda like a dirtbike engine. the only thing that i dont get is the reed system. it looks like a rotating flower in the diagram?? if any of you have some tips and tricks, please, please pass them my way. thanks in advance! also kris, i think i had it trimmed up to high and it was sucking air. dont know why it would do this now, and not every other time ive trimmed up, but you live and learn.

Re: my 80 hp merc died today

Pistons are over $100 each. So, you might like to just replace the one that seized. Bore that cylinder oversize and replace with OS piston and ring set. You may hone and rering the others. Seloc manuals are lousy. A Merc manual is better. The reeds are simply one way vavles. If they are not broken, leave them alone. Keep the bearings for each rod together, and mark the rod caps so you may reassemble them the same way. You will need to stick the rollar bearings into the rod end with grease to hold 'em while you reassemble.

Normally engines will ventilate prior to loosing water intake ability. Replace the impeller and clean up the carbs, prior to installing new carb gaskets, needles and seats. Inspect the floats for deterioration or cracks.

Re: my 80 hp merc died today

just got off the phone with the local machine shop, they said they might not be able to do the machine work on my block because their machine over strokes the cylinders, and my block has the head cast on it. does anyone know of a machine shop that could either re-sleave, or bore this kind of block??

Re: my 80 hp merc died today

You will have to phone around for a shop capable of boring a "blind" cylinder. Many of the small engine repair shops have the capability. I have found that ones specializing in snowmobile engines tended to have the capability more so than others.

Re: my 80 hp merc died today

chris. i heard that if you over size one cylinder, it will either run lean, or the others will run rich. and i found locally an 84 125hp force for 1500. dont know much about them, but thats a pretty good deal with power tilt n trim. i havnt been able to find a shop locally that can bore a blind hole, but i havnt given up. theirs lots of machine shops around.

Re: my 80 hp merc died today

Kartman, That is not true. You are only boring .002" oversize, so the effect on compression, displacement and carburation is negligable.

Re: my 80 hp merc died today

everyone ive been talking to has been talking about at least 10 thou, if not up to 30 thou.

Re: my 80 hp merc died today

Standard oversized pistons and rings are 0.015 and 0.030 over. The cyl would need to be rebored to the approp size. If you are able to get away with just honing the cylinder then you would be talking just a couple thou and could use standard size pistons and rings. A qualified shop will need to measure the cyl to determine if it needs to be honed or bored. There is only about a 0.005" permissible tolerance.