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Little to no compression

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Hello how's it going. I have an 88 30 hp Johnson motor that been sitting for ten years. The compression in it sucks. It will go up to about 30 in each cylinder, then leaks down to nothing. The motor ran good before it was put away. Of course it won't start like this and just backfires the odd time out the exhaust. I was wandering if anyone had any suggestions before I pull it apart to have a look
Thanks
 
You might spray fogging oil in the cylinders and retry your compression test. It's possible the rings are stuck. However, at 30PSI you probably have bigger problems. I've seen oiled cylinders read a little higher but my guess is that engine should have at least 100PSI per cylinder.

KJ
 
30 and even could very well be a head gasket. Pull the head and inspect the cylinder walls. If there is no scoring present get a new head gasket and lightly surface the head. On a glass table with 220 grit paper swirl the head in a figure 8 pattern until it all shines the same. Slowly torque it down with a new gasket in at least three steps in a center out pattern 216-240 inch lbs or 18-20 ft lbs.
 
How about spraying some ringfree in plug holes to loosen rings up,let sit a few nights and recheck compression with a known good gauge before tearing head off of engine, you did mention she was running before storage, more than likely she was not winterized properly 10 years ago
 
Thanks for all your advice. I tried the some of the tips and got a little more compression out of it. Still just backfires though when u try to start with fuel in the cyclinders just happens quicker now . I have the lower unit of it cause it needs a water pump so when it backfires smoke comes out the bottom. I was hoping to get it to fire before I spend money on the water pump. If the rings were broke would it pop like that? Could it also be a valve stuck open or something? Looks like I should probly just pop the cover of and have a look maybe.
 
Pull the flywheel sounds like the key on the shaft has a crease or has sheared off. If so gert some valve lapping compound and reseat the flywheel taper to the shaft good a nd install a new key and torque the flywheel down to spec. Timing is fixed all it takes is a little crease in the key to throw it out of timing.
 
You dont have the spark plug wires on backwards? The top wire should have a metal band that says top on it?
EDIT From the PP is the orange blue stripe going to the upper coil/cylinder?
 
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If it was running properly when you put it in storage and only has 30 psi now, you have to do some reasoning. What could have happened while in storage? Stuck rings? Probably. But 30 psi is awfully low for just stuck rings. You are going to bite the bullet and do some inspection.

BTW, it doesn't have valves, so it isn't that
 
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I agree with kimcrwbr1 pull flywheel off, It's quite possible she ran with a very low compression before it was stored years ago and jumped time, Iv'e had a few small engines run with very low compression before,but no torque from them.
 
The wires are on correctly. My brother tells me when he moved it to another shed a couple of years ago it was seized and he freed up the engine. It's been easy to roll it over after that. Do u think when he freed it it would have broke the rings or is there a better chance the key got sheard off or a crease in it?
 
Pull the exhaust cover off the side of the engine and inspect the rings. Carefully push on the rings with a screwdriver if they are not springing back the ring is broken. When the compression is low and even that is normally a head gasket leaking between cylinders very seldom do two cylinders go bad the same from scoring almost always one will be higher than the other. Get a harmonic balancer puller and three long 1/4 20 grade 8 bolts and pull the flywheel. Screw the bolts in at least 5 threads and put enough pressure you think the bolts will break and then lift up hard on the puller while you smack the ram with a hommer it should pop right off. Inspect the plate for excess slop up and down that will throw it out of timing also enough to make you sctratch your head. I am not a big fan on running a engine if the cylinders were froze up without at least deglazing the cylinders and putting in new rings. But that is just me others have had good luck as long as the cylinders were not damaged. I would start with the flywheel key is the cheapest and you can cross it off of the list. Be sure and torque the flywheel nut before you fire it up!
 
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