No compression on one cylinder = ?

[UNCC Grad]

What could it possibly mean if a motor had suddenly lost power and when a compression test was done, it had no compression on one cylinder? Blown head gasket, worn rings? I can get a 1986 Suzuki Dt 55 with all the bells and whistles for practically nothing, but it has no compression on one of the three cylinders.

Maybe I can get lucky and it just have a blown head gasket?

[jerry]

and maybe jerry will win lotto this week !

[yanny_haulinbass]

Ahh...Ahhh...no. That's not how it works.


No compression on one cylinder indicates broken rings minimum. They usually cause some pretty good damage when they break.

[UNCC Grad]

So is is still worth getting? The parts alone have to be worth more than what I will give for it.

[jerry]

You Might Need A Sleeve , Piston , Rings . About 500 Hundred Bucks

[Raceman]

I can get a 1986 Suzuki Dt 55 with all the bells and whistles for practically nothing

I'd say that's about what it's worth. It's unlikely that it's a head gasket unless Suzukis have different characteristics than most other outboards. I'd strongly recommend that you pull the head and have a look before you buy. True, it may have some parts value, but first you've gotta find somebody else with a 3 cyl Suzuki that needs those parts. Worn rings don't cause total loss of compression in only 1 cyl either. If the compression really is zero, it's got more than just a minor scuff or seizure in that cyl. Did you check to see if the piston is going up and down? That would tell you if it's got a broken rod. Probably the best you could hope for is a hole burned through the top of the piston with no cyl damage. If the Suzuki is a looper (and it probably is, don't know my 'zukis) the hole isn't as likely.

[Markus]

As the guys have stated, it is very unlikely to be a blown headgasket.

Take off the head and have a look. It is most likely a burned piston. You need to figure out how much damage has been done to the engine in addition to the piston itself and how to get it fixed.

[UNCC Grad]

Sounds like too much is involved for a novice like me. I was told he had it on a pontoon and while traveling down the lake, it suddenly bogged down and lost power then shutoff. He trolled back to the dock and took it home, where he then hooked it up on the clamshells and it started right up, but idled rough. He did a comp check and the other two "looked good" but #2 was reading zero.


Maybe I just need to start saving up some money for a 95 or later Merc or Yam.

[Rickracer]

That will tell you just about all you need to know about what damage has been done. You could even take a few pics and post em. Knowledge is power and pics (usually) don't lie.

[yanny_haulinbass]

Rickracer gave you some good advice. Take a pic and post it.

[UNCC Grad]

The only problem is that the motor is 2 hours from me I may call the guy up and see if he has pulled the head or if he by chance would. With the price of gas, I realy don't want to make a trip up there to look at it unless I am going to take it home.


The guy says the motor still starts and runs. I may ask if he can check the spark on all of the cylinders and pull the plugs and tell me their condition.

[Raceman]

The guy says the motor still starts and runs. I may ask if he can check the spark on all of the cylinders and pull the plugs and tell me their condition.

That really won't tell you much of anything given the fact that you already know the compression is 0 in one cyl. Either get the head pulled for a look or pass on it.