Mercury 1994 2.0L 150

[Glastron1987]

Didn't think to look. This is the first time I've had to open up one of these. Will take a look and post it.

[FMP]

Hope it's just a gasket set. Kind of looks like ate a reed once. Might have hurt a ring, things look a bit rusty. You're into both heads off and a good soak clean with seafoam at the very least. Consider some rusty bearings as a possibility. Maybe take a closer look with the power head apart and save yourself a bigger mess in a short time. If you oiled the bores before doing the compression test all those numbers except for one are low. The seafoam soak could help but have a good look at that #3.

[Glastron1987]

All the readings were taken without oiling just prior and were performed multiple times. Additionally, I oiled up #3 and tested it a few times and saw how it went up but after a few tests settled back down again. There is some rust almost everywhere. Unless Seafoam is supposed to be better I have lots of Marvel oil and WD-40 for attempting a cleanup.

[rock]

If you have rust "almost everywhere" you better keep digging. Rust on crank or rod journals can spell instant death. Hopefully it's only the sleeves.

Rock

[FMP]

Rusties, take it apart and check everything.

[Glastron1987]

Still trying to avoid total disassembly but I understand that may not be the best thing...

For now, #3 has been mostly cleaned up. It does have some scuffing, but best I can tell not any worse than the cylinders with good compression. Also, I don’t think it ever ate a reed. The #3 reeds look intact. Also, the decking looks good to me.

My thought is that I’ll clean up the other two cylinders on that bank (mostly the carbon) and then try a new head gasket and see how compression is. Oh, still have to deal with that head too.

[FMP]

Reeds can be replaced. Good luck

[tlwjkw]

Still trying to avoid total disassembly but I understand that may not be the best thing...

For now, #3 has been mostly cleaned up. It does have some scuffing, but best I can tell not any worse than the cylinders with good compression. Also, I don’t think it ever ate a reed. The #3 reeds look intact. Also, the decking looks good to me.

My thought is that I’ll clean up the other two cylinders on that bank (mostly the carbon) and then try a new head gasket and see how compression is. Oh, still have to deal with that head too.

don't be so hard headed and "cut" corners.. ya gonna have junk in every orifice, crack n crevice that has ta be cleaned out.. pull tha crank out and take a look at it and ALL bearings... it ain't gonna live even if ya get it runin' tha way ya goin' 'bout it............. jmo.

[Glastron1987]

I am hard headed. Although I'm listening.

btw is this one of those engines with compression relief notches? I see a notch in the exhaust port. Was wondering if thats what it is?

[Glastron1987]

Also, anyone know how far the heads can be cut and still use regular gas?

[FMP]

Have the crank out of it yet, how's the lower main?

[FORBESAUTO]

I am hard headed. Although I'm listening.

btw is this one of those engines with compression relief notches? I see a notch in the exhaust port. Was wondering if thats what it is?

Yep, that's the compression relief

[Glastron1987]

So I've read that the engines with the compression relief could read low on a regular compression test. Is it possible that my low reading on only #3 could be caused by that? If not, then I'll have to look for another cause, but if so, why would the others read normal?

[FMP]

How do the wrist pin bearings look?

[Glastron1987]

Not sure if there is a way to determine that without taking the crank out. If I do that it won't be for a while because of a workspace issue I have right now.