Need help with an old Mercury inline-6

trihul

Cadet
Joined
Aug 22, 2010
Messages
6
hey all.. first, I'll say this, I am not new to outboards, but i am brand new to mercury.. so this thing has been a head scratcher in some aspects.

I picked up this.. 60 something, mercury 95hp it is supposed to be. simply because it passed a leakdown, and compression readings are all in within 5% of each other.. so I have decided to make it something. I have allready used it, the thing starts up quite easily, and really goes on topend. SOMETIMES.

Other times, the motor will start,, acelerate, and then,. just.. drop off? like hit a wall, wont go any faster, not reaching full RPM. it FEELS like only half the motor is running when it does this. doesnt want to stall or anything, just will NOT climb into the higher range. other times, it takes right off like a bat out of hell.

I did some experimenting, and when it hit this "wall" I put it back in nuetral, and used the idle lever to the max.. the motor will rev to that point, hang there a minute, then finally clear out and run at full rpm. I played with it a little, and it doesnt appear to be a fuel issue, it appears to be an ignition issue.

I figured it was a solid enough foundation to give a full tune and get going 100%, surely there is something simple that has been neglected over the years.

Anyways, I started digging in, its a nice greasy mess, fuel pumps and carbs need rebuild kits for sure, and I took off the dist. cap, and my rotor appears to have been broken at some point. my best guess is someone with a flathead if you know what I mean by looking at the picture.

Sorry for the huge post... To get to the point here, I want to order a few parts for this motor, but am having trouble finding out WHAT to order.

first off, identifying just what this motor is...

I am a little thrown off by the fact mercury didnt use a model number.. just a serial number, it makes this whole process that much more of a pain.

so heres the facts I know for the guru's

S/N - 1893925 (on transom bracket, as well on engine block)
the word "Tiger" on engine side
836-2486 above tiger
1011-2484 - on head cover
933-258t - on block behind carbs
1128-1890 - on block under flywheel
the kiekhaefer emblem scattered about the whole engine (on castings and parts)
2 big can coils
plug caps say "kiekhaefer thunderbolt"


anyways, what I need to do is rebuild the carbs, fuel pumps,. impeller, lower seals, new plugs, etc.

Looking through carb kits, I wasnt sure how mercury worked, do you have to order a kit for every carb?

What plugs should this motor be running? right now it has NGK B8HS

I should probably replace that rotor thing right? is that thing made of gold or what??

What other wear items should be replaced or checked in the ignition?

Is there is a simple solution to replacing these mercury fuel lines? or do you have to order every individual piece with fittings on each end?

Anything else anyone can think I should check / replace on this motor is appreciated

I do have a generic mercury manual on the way, but I'd really like to get some parts coming in the mail, the weather is beautiful!

I took lots of pictures to help you help me (hah)


Thanks everybody!!




100_4188.jpg100_4208 - Copy.jpg100_4191.jpg100_4197.jpg100_4206.jpg
 

turtles11756

Petty Officer 1st Class
Joined
Dec 5, 2007
Messages
260
Re: Need help with an old Mercury inline-6

the serial # on block would be a 1965' 90hp. the faceplate in pictures a 67' 950SS. i think a 90hp but it's hard to tell with these old models. it should have ignition points in distrbutor. soon after merc went to a trigger instead of breaker points which will id the correct spark plug it needs. no matter that's a heck of a motor. you will need the service manual for it. a parts list is available crowley marine .com. the ignition wires screw in at distributor cap. .use barbed brass fittings for new fuel lines original repros are available for $$$$. check all the wiring for rotted wires..the parts are all available and if you look around can be had at a good price
 

trihul

Cadet
Joined
Aug 22, 2010
Messages
6
Re: Need help with an old Mercury inline-6

the serial # on block would be a 1965' 90hp. the faceplate in pictures a 67' 950SS. i think a 90hp but it's hard to tell with these old models. it should have ignition points in distrbutor. soon after merc went to a trigger instead of breaker points which will id the correct spark plug it needs. no matter that's a heck of a motor. you will need the service manual for it. a parts list is available crowley marine .com. the ignition wires screw in at distributor cap. .use barbed brass fittings for new fuel lines original repros are available for $$$$. check all the wiring for rotted wires..the parts are all available and if you look around can be had at a good price


There is no points anywhere on this motor I can see. I just ordered a replacement rotor for my busted one, carb kits, fuel pump rebuild kits, impeller.. etc.

most of the parts said they fit a wide variety, so they should work either way.

would still be nice to know what it is.. the lower unit has the wrap around sticker 95hp.
 

kax2000

Petty Officer 2nd Class
Joined
Jul 17, 2011
Messages
162
Re: Need help with an old Mercury inline-6

Remove the plate above the rotor.
 

merc850

Commander
Joined
Jul 7, 2010
Messages
2,055
Re: Need help with an old Mercury inline-6

The points are in the distributor housing I6-distributor-1.jpgI6-distributor2.jpgyou have to undo the 4 bolts and remove it to set them, also check the belt that drives the dist. for aging cracks etc.
Merc-I-6-wiring.jpg
 

turtles11756

Petty Officer 1st Class
Joined
Dec 5, 2007
Messages
260
Re: Need help with an old Mercury inline-6

you might want to just clean the points lightly with a points file before you fool with them
 
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