250 ox66 - Salt weepage on head gaskets and compression

[31jupiter]

Im purchasing boat with 2001 250 ox66 engine with about 800 hrs. The compression tested all cylinders 110-105 cold, which i assume is ok. My concern is the salt weepage on the head gaskets. Is that a red flag for anything or just have them changed and all is ok?

Thanks.

[rodbolt17]

that thin line of corrosion/weepage is entirely normal.
typically the compression numbers will be about 110 on cylinders 1,3,2,4 and about 105 on cyl 5,6.
on Yamaha V motors you compare bank to bank not left bank to right ban.
1-2,3-4,5-6.

over the years on various v motors(and some inline 3 models) Yamaha changed the compression from top to bottom by machining the combustion chambers to different CC's.

why?? never got a good answer but they did.

as to changing the gaskets, that's entirely your call.

[31jupiter]

Thank you, that helps!

[31jupiter]

Pictures or head gasket saltwater seepage.

Just a follow up with a picture to see if this is still ok??

Thanks,

[BQUICK]

That's pretty crusty!
I would re-torque the heads and flush real well preferably with SaltAway or the like. I wouldn't be surprised if over heat comes on now over 4000 rpms with the way that looks.

Very likely bolts will snap if you try to change head gaskets.....

[Offshore_life]

I would carefully try to remove all the bolt replace all the gasket.

[31jupiter]

Removal suggestions

Thanks for the replys. I agree that they do seem very crusty. I would prefer to change them but have also heard that the bolts can break. That being said, if I decide to change them, is there a method to avoid breaking the bolts? Does warming the engine help? Does tapping each one first do anything? What about slightly tightening then backing out?

Thanks again for any advice.

[99yam40]

all you can do is cross your fingers and hope they will not break.

Looks like more than just weeping from gaskets
it is everywhere.

No one ever washed and sprayed down the undercowling motor parts

[BQUICK]

I had a similar situation (1989 Florida motor) and elected to leave it alone and flush as best I could. Only in the hottest days in the middle of summer did it trigger the overheat. Ran for another 7 years like that. The other motor on the other hand broke numerous head bolts trying to get the heads off. But then again it had one cylinder with low compression so it didn't bother me that much.
Your compression looks OK, so I say run it.

Some may dispute it but I say being a mechanic means knowing when to leave well enough alone.......

[jb123]

Looks like they slacked on maintenance to me, rarely rinsed

[31jupiter]

Going to run 'em for now.

Yes, definitely a neglected pair of motors. Didn't deter me from the purchase. Hope to get some life from them.

After careful consideration of replacing head gaskets, I will likely run them for now, check how engines are are performing and then, if required, replace.

If anyone can add any additional info, much appreciated.

Thanks for all responses.

[BQUICK]

I would pull thermostat covers and see how bad it looks in there....and replace stats.

Optional: pour white vinegar in there when the stats are out and the motor tilted up. Put stat covers back on without stats. Wait 30min and run on hose for a while. Put stats back in. This will help remove some of the salt buildup.