No Compression in one cylinder. 1978 200 HP Mercury

[nitroscott]

Not really sure of the year my outboard id because there is id plate. My first problem is that the starter spin hard but the bendix wont come out of the starter and engage with the flywheel, with a fresh 13 volt battery put directly to starter. Then my big problem is since I cant turn the motor over with the starter, I put a ratchet on the flywheel nut and turned the motor clockwise and all of my cylinders blew my finger out of the spark plug hole except the lower left hole. I cant feel anything in that hole. I was going to try a leakdown test of that cylinder tomorrow. Can anyone tell me what might be wrong with that cylinder or other tests. I bought the boat and didnt hear it run. Thanks ahead of time.

 

[sptjet90Reflexx]

does that motor not have a flywheel designed for pull starts?

 

[nitroscott]

Yes I found a pull rope in a bag in the cowl.

 

[sptjet90Reflexx]

put a compression tester on that cylinder and pull start it. a few times. Make sure ignition is disabled.

 

[nitroscott]

I have the battery unhooked, is that good enough?

 

[nitroscott]

The plugs look like new on the side that has the bad cylinder and the good side the plugs are lightly used. I hope this indicates a bad head gasket.

 

[nitroscott]

If someone could just give me a link of a past threads on this subject. Thanks

 

[Dukedog]

First thing is if your serious about fixin' tha thing is tha starter. No starter ta spin it at rpm ya can't diagnose anything essential ta makin' it run..........With it not engagin' with hot battery direct could be bendix or starter itself.......

 

[nitroscott]

Yes the starter turns very hard but wont kick out. So do I just buy the bendix drive piece or the whole bendix?

 

[nitroscott]

I guess I can do a leak down test like on a four stroke? I have never torn down a 2 stroke. But I am serious about fixing it, I will rebuild it if I have to.

 

[Dukedog]

If your "handy" with mechanics try takin' it apart givin' it a good cleanin' if there is no apparent damage to anything.....If its gotta have parts ya need ta identify tha motor. In tha eary years of tha V6 there are same different starter/flywheel combinations......

 

[nitroscott]

Yes I was thinking that the threads in the bendix drive gear are shot. Probably the drive gear threads are softer than the shaft threads. Will the leakdown tell me anything on a 2 stroke, do you think im right?

 

[Dukedog]

I guess I can do a leak down test like on a four stroke? I have never torn down a 2 stroke. But I am serious about fixing it, I will rebuild it if I have to.

Yes you can but that will be tha extent of any testin'. Just something to consider. If its a first generation block its really not a good candidate.......

 

[nitroscott]

Not a good canidate for rebuilding?

 

[Dukedog]

Leak down will tell. Not a good candidate for rebuild.

 

[nitroscott]

Yes I am hoping it is a head gasket. But I am ready for a sleeve if needs be.

 

[nitroscott]

I was hoping it is just a head gasket but I am ready for a sleeve if I have to. I need to get back on the water. Its on a 18' Glastron Bass boat I think it will be scary fast.

 

[sptjet90Reflexx]

Is the bendix gear stuck? I had that happen on a starter. had to sort of gently pry it up and it would engage fine after that..

 

[nitroscott]

Hey I took the head off and found a piston all beat up and I lubed the starter shaft and it fixed itself. I wanted to thank everyone for their help I really appreciate it. Love this forum.

 

[nitroscott]

Does anyone know how much I should pay to have a sleeve put in the block at machine shop.