Johnson 175 bad compression

[Keyboardman]

2000 Johnson 175 model# J175VXSIF I did a compression test of this engine and readings are are all over the board. Right side readings were 100 top 70 middle and 100 bottom. On the left bank they were 0 at the top, 50 in the middle and 100 in the bottom cyl. We did the test with all the plugs out and a shot of WD40 in each cyl. How could it be that one cyl has zero compression? I understand this engine has O rings instead of a head gasket. Can they just fail and cause these bad compression readings? Thanks

 

[racerone]

Nope----Just remove the cylinder head and it will be obvious what is wrong.------Scored cylinders or a hole in a piston

 

[Keyboardman]

Thank you Racerone, I don't have the manual for this engine, is there a bolt tightening sequence that I should follow in reverse to remove the head?

 

[racerone]

Just take the heads off.-----I do not believe you need to worry about a removing sequence of the bolts or installing the heads again for a while.

 

[Keyboardman]

Thank you once again.

 

[racerone]

Post some close up pictures of piston tops and cylinder walls.-----I like pictures of this damage.

 

[boatflipperz]

Just take the heads off.-----I do not believe you need to worry about a removing sequence of the bolts or installing the heads again for a while.

That was a very nice way of saying there's a 99.9% chance his motor is toast.

 

[Keyboardman]

I'll pull the heads off when I get it home. I'm mainly interested in the hull but maybe this one isn't too far gone to rebuild? I'll post pics.

 

[racerone]

What did you find ?----Pictures.

 

[Keyboardman]

What did you find ?----Pictures.

I haven't brought the boat home yet. Been raining forever here on the NC coast and the trailer needs a little work. I will certainly post pics as soon as the heads come off. From speaking with the clueless previous owner, it looks like he didn't bother with calculating the oil mixture when he filled up the onboard tank. No oil = fried engine. I did come across an Evinrude 200 to repower, I need advice on.

 

[ct1762@gmail.com]

I haven't brought the boat home yet. Been raining forever here on the NC coast and the trailer needs a little work. I will certainly post pics as soon as the heads come off. From speaking with the clueless previous owner, it looks like he didn't bother with calculating the oil mixture when he filled up the onboard tank. No oil = fried engine. I did come across an Evinrude 200 to repower, I need advice on.

was it premix?

 

[oldboat1]

2 reasons for some hope. Might have been set up for premix (above), so use a portable tank with a 50:1 mix to test. Also, get your hands on another compression tester (borrow from an auto parts store, possible), and retest. Do the compression test first -- if as bad as it appeared, don't try running it.

 

[Keyboardman]

was it premix?

2 reasons for some hope. Might have been set up for premix (above), so use a portable tank with a 50:1 mix to test. Also, get your hands on another compression tester (borrow from an auto parts store, possible), and retest. Do the compression test first -- if as bad as it appeared, don't try running i

 

[Keyboardman]

I'll re check the compression but am pretty sure it's toast. The VRO is gone and he was just putting some oil in the onboard tank and filling it back up with gas. No idea what possible mixture he was running! I'll post pictures but for right now, I've picked up a '96 Evinrude Ocean Pro 200 to repower the boat.

 

[FreeBeeTony]

See you bought another engine.....
Does this mean we won't be seeing any pics of the 175?

 

[ct1762@gmail.com]

i second some pics of the damage. pretty easy to tell if it was a no-oil situation. if a couple cylinders are undamaged=good bet it wasn't lubrication that did her in

 

[Keyboardman]

I'm dying to get the boat home but it's been non stop rain here. Will investigate the old engine completely before removing it from the bracket and post what I find.