1986 115hp merc problems help!!

[jeesybubba1]

just got a 1986 inline 6 115hp the motor starts and has good compression it will bog down under load and not pass about 2000 rpm carbs were rebuilt running on aux tank so gas is good where do I start I have the manual but thought maybe someone here may have had this problem in the past. any help is apreciated. thanks in advance

 

[Lone Duck]

Re: 1986 115hp merc problems help!!

just got a 1986 inline 6 115hp the motor starts and has good compression it will bog down under load and not pass about 2000 rpm carbs were rebuilt running on aux tank so gas is good where do I start I have the manual but thought maybe someone here may have had this problem in the past. any help is apreciated. thanks in advance

Do your link & sync. If the carbs have been done correctly,and you have good spark , good compression , clean fuel, all lines and vents are good, fuel pump is good ,then link & sync should be checked. Have fun.

 

[Chris1956]

Re: 1986 115hp merc problems help!!

Bubba, That ign system has a low and a high speed winding in the stator. Sometimes the high speed winding fails.

Get on the CDI Electronics website, and run the test on the stator for the ADI ignition.

 

[jeesybubba1]

Re: 1986 115hp merc problems help!!

thanks I will trey these things and get back

 

[jeesybubba1]

Re: 1986 115hp merc problems help!!

ok well its worse than I thought power head is siezed wont turn over at all this was the first time I tried to start it in a while the bottom plug has rust on it so I guess that cyl is froze is it a total loss I dont have money for a rebuild.

 

[Chris1956]

Re: 1986 115hp merc problems help!!

Itis not necessarily a total loss. Tilt motor up. Remove pluga and spray some penetrating oil into all the cylinders. Take a brass rod and put it thru the bottom cylinder and tap it to loosen the rusted rings.

You can remove transfer covers to verify the bad cylinder is #6. Chack #5 as well.

Check the compression. It may come back, or it may not. Anyway, you need to pull the exhaust cover and see where the water leak is. Might be just new gaskets are needed.

 

[jeesybubba1]

Re: 1986 115hp merc problems help!!

Thanks got the motor to turn over did what you said. I have not taken the exhaust cover off yet will do that tommorrow any tricks on getting that off ? I can see the lower bolts are very hard to get to. And Im afraid of breaking the others off had that happened before too.

 

[Chris1956]

Re: 1986 115hp merc problems help!!

It is best to pull the powerhead (LU first), and put the block on a bench. Use some heat and penetrating oil, along with a hand impact driver to remove the exhaust cover. Heat bolt, apply oil, let cool and then use impact driver to coax them out.

 

[jeesybubba1]

Re: 1986 115hp merc problems help!!

I got the motor running and did compression check all real close to 125 does this rule out the exhaust leak maybe just water in the bottom cyl from sitting ?

 

[jeesybubba1]

Re: 1986 115hp merc problems help!!

well not really running but cranking and it ran for a few seconds till it stopped probably from lack of fuel

 

[jeesybubba1]

Re: 1986 115hp merc problems help!!

ok now got it running will run but is still getting water in the bottom cyl guess it is the exhaust not a job I think I should mess with . any good mechanics in baltimore?

 

[Chris1956]

Re: 1986 115hp merc problems help!!

The other place water will leak in to the bottom cylinder, is past the crankshaft seals. Have the mechanic change those as well. Actually, the exhaust cover may be OK, if the water is isolated to the #6 cylinder. There is no real way to tell.

 

[jeesybubba1]

Re: 1986 115hp merc problems help!!

thanks I will let you know what happens> There is no way this could be a crack in the block or something like that right?

 

[daveswaves]

Re: 1986 115hp merc problems help!!

thanks I will let you know what happens> There is no way this could be a crack in the block or something like that right?

It could be a crack in the block but it is more likely the bottom seals or the exhaust plate. No guarantees unfortunately.