70 lb compression on mariner 150???

[lookingforluck]

Re: 70 lb compression on mariner 150???

When you say hard to start do you mean like having to try six or seven times before it does start? That is what I had to do today. I reached in and it turned over probably 5-6 seconds before it hit and then I had to try another 4 or 5 times but not that long before it did fire up.

 

[lookingforluck]

Re: 70 lb compression on mariner 150???

I am going to order some head gaskets, are they very difficult to put on? Will this help any with the compression?

Thanks

 

[redjmp]

Re: 70 lb compression on mariner 150???

There is no point in ordering just the head gasket as it is not the culprit.
Sounds like you ran out of oil. I'm sure if it was an over heat , that it would have tripped the alarm and you would have more damage at the top of the engine. As well you would have had to replace the impellor. That is unless you sucked so much sand into the cooling passages that the whole motor slowly overheated.
I would bet if you pull of the heads that you will see some damage to the walls and rings. This may be repairable with just a rehone and new rings if you are lucky and the pistons aren't too badly scuffed.
It may be worse and need a rebore and oversize pistons and rings though.
Either way, you will need a complete overhaul and it would be cheaper to buy a complete gasket kit all at once, rather than getting head gaskets now and installing them only to find out it is not the problem. You would have to replace them again as once you torque them down, they are not reusable.

 

[lookingforluck]

Re: 70 lb compression on mariner 150???

Ran out of oil? Would that have some kind of alarm? The overheat alarm did not go off............

 

[lookingforluck]

Re: 70 lb compression on mariner 150???

I am going to get another compression tester to double check myself. I can't believe that is right because it wouldn't be starting and running very good with that compression. If the new readings are 100 or above, then what might my problem be? I tried the turning of the flywheel and holding my finger over the spark plug and it would blow my finger off, just barely. I didn't hear the air really escaping anywhere except the other plugs.

 

[redjmp]

Re: 70 lb compression on mariner 150???

Ok try this. Test the compression again but then squirt a good shot of raw oil or wd40 into the cylinder and try again. Do the readings come up quite a bit?
If no try another compression checker or take the boat to a shop and have them do a leak down test on one or 2 of the cylinders.
If yes, you need a rebuild or at least a rering. Time to take the heads of and see what the walls look like.

 

[lookingforluck]

Re: 70 lb compression on mariner 150???

I was scared to tear into the heads and have taken the motor to a mechanic, he will get to it sometime next week.

 

[lookingforluck]

Re: 70 lb compression on mariner 150???

I took the boat to a mechanic and it was the carbs, he took them off and cleaned them. He said that they didn't look bad but that is the only thing that he did to it and now it will run 5600 rpms??? Does anyone know the max rpm's I should be running? He also turned up the oil injection and it helped cool the motor down some.

 

[lookingforluck]

Re: 70 lb compression on mariner 150???

Compression with another guage 105, pretty even all across the board. Still not good like others are getting but it is pretty even.

 

[NGABaldEagle]

Re: 70 lb compression on mariner 150???

Excellent!!!!!!
I am happy that was all it was.

Happy Boating!