1996 115 2+2 Case Halves

[EMC 1810SS]

I picked up a decent 1996 Mercury 115 2+2 that has the carbs off and was missing a few part. The carbs turned out to be very dirty and 125 castings with the wrong jets in them. The compression is 136 to 140 in all holes. The previous owner says the case halves were sealed with the wrong material. As I understand it, it should be an anaerobic gasket material? the sealant used is black? I am not convinced that is the idle issue. Given the state of the carbs I am surprised it started. If it was yours what would you do? I can put all the parts back on, and run it and hope the case sealant isn't an issue, or since its not on the boat, break down and split the case and re seal it?

Thoughts?

 

[Chinewalker]

Re: 1996 115 2+2 Case Halves

Any evidence of seepage? If nothing (oily fuel) is leaking out, chances are nothing (air) is leaking in. I'd leave it be..

 

[racerone]

Re: 1996 115 2+2 Case Halves

On more than one occasion have I measured the film of sealant on recently rebuilt / scrapped motors.--Found it to be far too thick ( 0.008" ) measured with micrometer.---What this means is that bearings were not clamped up properly and were loose.---If it was my motor I would take it apart and see what was done here.---Does not sound like an experienced rebuilder / mechanic worked on it !!----The bottom 2 carburetors have different low speed jets.--At idle only a wee bit of fuel goes in the bottom 2 cylinders for cooling and lubrication.--It only idles on the top 2 cylinders.

 

[EMC 1810SS]

Re: 1996 115 2+2 Case Halves

Do I have to pull the power head to split the case or can I get it apart mounted to the lower unit?

 

[racerone]

Re: 1996 115 2+2 Case Halves

Powerhead must be taken off the exhaust housing !

 

[wired247]

Re: 1996 115 2+2 Case Halves

Why would you pull the case apart? If its running and there is nothing blowing out at the parting line, leave it alone. You have a carb setup/timing problem. The crankcase sealant has nothing to do with it.

 

[EMC 1810SS]

Re: 1996 115 2+2 Case Halves

The only issue is it is on the stand right now and would be WAY easier to pull apart now rather than when I put it all back together. I am tempted to give it a go though. I know the carbs were not right. I have the proper jets now, but two were way to small and the bottom two were the proper size for the top carbs. It turns out they are 125 castings so I am matching the jets to the 125 specs.

 

[racerone]

Re: 1996 115 2+2 Case Halves

On this motor the bottom 2 carburetors are different.---Idle jet is very small and only a little bit of fuel goes in for cooling / lubrication.---The top 2 carburetors usually have an ajustable idle needle.