79 evinrude 85hp crossflow, running bad

coolbri70

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wish I could share some youtube video I made keeps telling me invalid url, used to work just fine
 

coolbri70

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:lol:we're all cadets now, hate to complain, but really,:rolleyes: how long has it been now?
 

Bosunsmate

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It will be two months before too long, too long to blame the world cup.
you can just paste the link to youtube in the normal reply box that works still
 

coolbri70

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No Title

stayed at work late, did some parts washing and ring groove cleaning
 

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Bosunsmate

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i thought the train was honking at you for a while there.
that bolt is where i often have a problem too, i think that the intake and outlet for a lot of the water is near that bolt so it probably eventually gets oxidation and all that much earlier than the other bolts.
That cracked part i would imagine would be a real pain to get to, on any motor ive worked on (they are all salties) ive never being able to strip it down further without doing copious amounts of damage. The next bolts are even harder to remove.
id just jb weld it myself, maybe someone else can advise you more on that but that was my experience of trying to get further into a v4 of that age
 

coolbri70

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i thought the train was honking at you for a while there.
that bolt is where i often have a problem too, i think that the intake and outlet for a lot of the water is near that bolt so it probably eventually gets oxidation and all that much earlier than the other bolts.
That cracked part i would imagine would be a real pain to get to, on any motor ive worked on (they are all salties) ive never being able to strip it down further without doing copious amounts of damage. The next bolts are even harder to remove.
id just jb weld it myself, maybe someone else can advise you more on that but that was my experience of trying to get further into a v4 of that age
yes I think I will jb weld that, just to keep water out, still feels solid and looks like its been there for a long time, I live a block away from the tracks, get used to hearing trains:D
 

Bosunsmate

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Whats your plans on the bore? honing, wet sandpaper or is it fine to just leave it as is?
Yes i live in the country, i definitely havent heard one of them for a while
 

emdsapmgr

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Dec 9, 2005
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Looks like original high-ring factory pistons from that year. They were a problem back in the day. Many, many of them caused powerhead failures over time. OMC took a hit for warranty, so re-engineered them after a few years. You will find a replacement factory piston will have the ring grooves lower than your other 3 originals. They will work just fine, just make a few lbs less compression than the originals.
 

coolbri70

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Whats your plans on the bore? honing, wet sandpaper or is it fine to just leave it as is?
Yes i live in the country, i definitely havent heard one of them for a while

I scuffed away the glaze with sandpaper, I didn't do much though, there were actually still faint crosshatch marks
 

coolbri70

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Looks like original high-ring factory pistons from that year. They were a problem back in the day. Many, many of them caused powerhead failures over time. OMC took a hit for warranty, so re-engineered them after a few years. You will find a replacement factory piston will have the ring grooves lower than your other 3 originals. They will work just fine, just make a few lbs less compression than the originals.
yes, the rings are at the face of the piston, I ordered the oem replacement, didn't know it would be different, wish I could afford to do all the pistons, but it would have made it too expensive, cheaper to replace the engine at that point. I tried to talk the admiral into letting me get a project boat with a good motor, but rotted floor and transom, that I could take the motor from but she didn't believe I would dispose of the hull, claimed I would try to keep it too. like I would do that, it was a nice little 18' starcraft just needed a little tlc. maybe she was right. I would have tried to restore it but there is room in the yard
 

coolbri70

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I just looked at the pictures of the piston I ordered, ring grooves are a lot lower, hope its ok and the 3 originals hold up, one had a stuck ring, but I cleaned it up and now the ring moves freely
 

emdsapmgr

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As long as you have it apart, replace the other 3 ringsets. No point in reassembling it with three old ringsets and have one of them fail next summer.
 

coolbri70

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As long as you have it apart, replace the other 3 ringsets. No point in reassembling it with three old ringsets and have one of them fail next summer.
yes, I have the ringsets coming, I meant I wish I could replace the pistons so they would all match, the ring being further down on the piston. in addition to the broken piston, I had one with a stuck ring that was letting compression past, there was black smutch in the groove and down the skirt. I thought I had the wrong prop, glad I didn't replace it, because it was not the reason my rpms were under range, guess I should have done the compression test sooner
 

coolbri70

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my omc service manual came yesterday:D, now if the parts would only arrive:pray2: vacation starts Friday, I wanna go boatin
 
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