Not looking good...
https://youtu.be/zw-FiwnBwkU?si=DpMdLOeqJa2Y6G8a
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Not looking good...
https://youtu.be/zw-FiwnBwkU?si=DpMdLOeqJa2Y6G8a
Ran without oil to me. The aluminum can grip like no other metal except maybe Titanium. Not sure how you would repair the Head casting but someone might. I will check my Yamaha 4 Stroke rebuilder and see what he says.
Heads out. And to me it looks OK!
https://youtu.be/1VRh7GLSy3g?si=bIJswBlpCYWIFksQ
And Rojo, I see some heads for sale on Ebay, and guess what, their top cam bearing looks same as mine, bad! lol
Attachment 477121
This is a snapshot of one being sold on eBay. I'd say mine looks better, at a bit better. Doh
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Attachment 477122
And here's my bad one above.
The other one of my cam bearing below is gooderer:
Attachment 477124
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Looks like the bearings were turning in their seats. That happens when ran with no oil.
These cam bearings are not separately replacable. The whole head would have to spin! lolQuote:
Originally Posted by Barnacle Bill
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May just be normal wear patterns. I would think that the cam shaft would have galded aluminum stuck to it if it ran without oil.
Camshaft side looks fine, smooth as silk.Quote:
Originally Posted by DockShootinJack
I am wondering if the marks are from start up. At times outboards sit for long periods of time. Sure could have less than optimum lubricant until oil pressure is built up. Engines would probably last a lot longer with an electric oil pump to get oil up into the motor before it was started.
[QUOTE=Slab;These cam bearings are not separately replacable. The whole head would have to spin! lol[/QUOTE]Quote:
Originally Posted by Barnacle Bill
So like a Ford 5.4 3V Triton overhead cam engine the casting is the bearing. Although vertical Cams are used allowing oil to drain there is no combustion heat to melt the aluminum enough to transfer to the steel camshaft. The heat is just not there. That being said those camshaft bearing valleys in the head casting did Gall on the aluminum side. The Ebay castings galled even further. Ford repairs their head castings by Line-Boring the casting with the clamps in place then installs a new camshaft with .010 oversized journals for the repair. Its a one and done, you buy a new casting the next time. I happen to have one of those engines in my Fishin' Expedition. Respectfully speaking the case must be cracked, Crank & Rods checked for low or no oil operation too. Without doing that you may be pulling the head right back off along with the Powerhead. We may be able to find a complete block, I will call Tuesday as my guy is way too busy with oilfield customers on Mondays. I have bought a ton of good Yamaha F250-F300 used parts from him and all were good.
Just watched your latest video on YouTube and the Cylinders were certainly getting plenty of oil and fuel. I agree the pistons and Cylinders should be fine. My :twocents comes in with the Seizure, if a piston didn't grab enough to stop the engine from turning I don't believe your Camshafts, with the little damage to the Head Casting stopped the Engine. I will log in and see what a full gasket set costs and PM you that figure. A blown Head Gasket didn't cause it to seize either. If you look in the manual I sent the valves are loaded with spacers and they will all be different. Don't take the head apart without reading that section in the manual first. If they ran it hot the Cylinders will still look fine but the rings will have lost their tension. I bought a 175 Eagle engine for my stash for $800 due to that. Great buy for me as I collect 60 Degree engines.
The 3.5 liter engine in my Tacoma has the same configuration as well as the Eco Boost engines I have seen. That seems to be the trend in engines now.
Attachment 477153
Does this look like your gasket set?
We can get individual gaskets too. Those in the picture. Said they fit a Mercury Engine too why I'm asking for verification on application.
The head gasket looks the same but the intake manifold gasket seems slightly different.
Attachment 477162
Also, upon further inspection, I found something on the bottom cylinder wall. Here you can see it. You can also see that I scratched it with my finger nail.
Attachment 477163
So I’m thinking there was some metal transfer. That’s the only place I found it.
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Rooting for ya Boss
You sure that's not coolant water? Was it run in Saltwater? The heat from the cylinder with coolant leakage will leave deposits. Aluminum transfer you can see, its sickening to those who don't know the acid trick. I'm not there but if a little white Scotch-brite removes it not to worry.
If you look in the service manual the tab on the Intake gasket will need to either go up or down. I see the tab is on a different hole but still pointing off the end of the gasket. Head gasket looks the same too. I'm looking up the prices now so you have comparison figures if nothing else.
Yep, it was run in the salty stuff. I’ll see if it cleans off tomorrow. Thank you for all your insight and help. It is much appreciated.
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Since you don't have ports in the cylinders a Ball Flex hone will put a good scratch for new rings. The 2 Strokes have camfers at the Ports that a Ball flex will damage. I would have to look up the grit size for the hone. I use diesel here for a hone lubricant but Ball Flex Hone Mfrs usually have their own lubricants.
Rojo, you sent me this in a PM: "Powerhead bolts on a Yamaha they are the worst. I use Kroil and if I can get it to move a little go very slowly working it a little then let it cool. Yamaha bolts are terrible for wringing off."
Now I'm worried about attacking those bolts. They are next on my agenda. The one thing maybe I have going for me is the fact that since the engine was redone 8 months ago with a new (used head), new (used block) and a new oil pump, maybe they'll be easy enough since they were recently removed and had spent less time in the salt. And supposedly, it was not run for four of those months. So, only occasional salty fishing on the weekends for four total months. He said it ran great during that time.
And I think I was able to clean up the bottom of that lower piston with scotch-brite. dono. feels smoother, looks pretty much the same.
Bud they should break. Gradually increase the pressure on your handle. a breaker bar is better since the longer handle allows you to feel how much torque you're applying easier. You are correct, they should come right back out. I install all mine using the Nickel Never-seize not the Copper, once the Nickel based material is in the threads they come back out forever.
Discoloration is normal, a buildup of Aluminum is not. See if you can see your hone marks thru the discoloration, if you can your good. Your pictures show the cross-hatch pattern well.