What year is my 4 hp mercury

[colsan]

I would like to find out what year this motor is, it is a blue band twin cyclinder motor, serial number 9 188880.
colsan

 

[carholme]

Re: What year is my 4 hp mercury

colsan;



4 1978 GNAT ML 9176522 - 9208836

From here:

http://www.maxrules.com/models/Merc_model_files/2p2-6.html

Parts listing:

http://www.crowleymarine.com/mercury-outboard/472.cfm

Gerry

 

[colsan]

Re: What year is my 4 hp mercury

Thanks Gerry, I unbolted the Thunderbolt 11 (black box) from the motor as I have no spark and on the rear it has July 25 1977.
I have a reading on my ohm meter before the black box but no power to the coils/spark plugs, Do you have an opinion on this?
colsan

 

[carholme]

Re: What year is my 4 hp mercury

colsan;

By "black box", if you mean that your engine has a switchbox, I have changed the parts listing in the previous post.

Is this the black box you are talking about, item 1?

http://www.crowleymarine.com/mercury-outboard/parts/472_4.cfm

Gerry

 

[colsan]

Re: What year is my 4 hp mercury

yes it is the switch box, but not sure if this is the problem, any suggestions?


colsan

 

[bktheking]

Re: What year is my 4 hp mercury

Pretty sure this is the same test (switchbox is 339-6222)

http://www.cdielectronics.com/downloads/troubleshooting guide/Mercury 2 Cylinder - 339-6222.pdf

I have the twin 4 hp of this year, is yours a twin or single?

 

[bktheking]

Re: What year is my 4 hp mercury

FYI this is a gnat twin 4 hp

http://louisville.craigslist.org/boa/2270878572.html

Same motor I have, the previous posts suggest it's a single???

 

[colsan]

Re: What year is my 4 hp mercury

No it's not a single cylinder, it has 2 cylinders & 2 spark plugs. it has stamped on the back of the switch box "July 25 1977"

 

[colsan]

Re: What year is my 4 hp mercury

this motor looks the exact same as mine, only mine has 2 cylinders. I wish this motor was in Queensland Australia! so I could get it.
I've got some items to check and eliminate now thanks to many of you, much appreciated, I will let you all know how I get on.

colsan

 

[colsan]

Re: What year is my 4 hp mercury

Can you tell me the position of where "START" is on the tiller handle ie; is it at twelve o'clock(on top), 1 o'clock, as mine is worn away

colsan

 

[carholme]

Re: What year is my 4 hp mercury

colsan;

When I changed the parts listing, I did not include the engine information to match the parts listing. I have changed it now and the parts listing is still the same and it is a 1978.

As bktheking has the same engine, I will let him continue.

Gerry

 

[bktheking]

Re: What year is my 4 hp mercury

This is a pic with the handle tilted back, the motor is on the wall in my garage, mine are worn off too but still there. The pointer is on start, you can see shift and slow in the pic.

PS- if you don't know already, the stop button is at the end of the tiller handle.

 

[bktheking]

Re: What year is my 4 hp mercury

this motor looks the exact same as mine, only mine has 2 cylinders. I wish this motor was in Queensland Australia! so I could get it.
I've got some items to check and eliminate now thanks to many of you, much appreciated, I will let you all know how I get on.

colsan

Way too much money for that motor, I picked mine up at a meet - needed a carb cleaning and an impeller, $50.

 

[colsan]

Re: What year is my 4 hp mercury

thanks for all your help Gerry

 

[colsan]

Re: What year is my 4 hp mercury

bktheking
Would you be able to check a couple of things for me on your motor, (a) 2 wires coming from the trigger assy, 1 brown & 1 white (they go into the back of the switch box) I put an ohm meter on them set on 200ohm and it read 149 without starting the motor can you see if yours is the same. (b) Is there a yellow wire on the screw that bolts the switch box to the motor.
I thinking the switch box is at fault, also backing my theory is there is a silicone patch on the 2 top wires at the back of the switch box, maybe someone has tried to work on it before.
I appreciate any help you can give!
colsan

 

[bktheking]

Re: What year is my 4 hp mercury

I will check. The resitance reading according to your reading is within spec,140-160. Did you try disconnecting the orange wire at the switchbox to eliminate the stop switch? What about the yellow wire disconnect?

 

[colsan]

Re: What year is my 4 hp mercury

I disconnected the orange wire, made no sparks, I put the ohm meter inline on orange wires & no reading on ohm meter while pulling the start rope. (appears to be no power coming from switch box)
I disconnected yellow wire, made no sparks, connected ohm meter as above, multiple readings up to 154ohm.
bktheking the switch box at the rear where the brown and white wire enters has a piece of the about 1 inch x1/2 inch filled with silicone as if some one has cut into the s/box to investigate a problem, I thought the s/box should be a sealed unit (all black material -no silicone).

 

[bktheking]

Re: What year is my 4 hp mercury

You need to test the stator and switchbox seperate using a DVA. Your resistance is within spec for the stator but that doesn't mean it's putting out power. Chances are the switchbox is bad however if you have unlimited funds to put into the motor replace the powerpack. I'm cheap, I even made my own DVA i'm so cheap and if you replace the box and it's the stator well then you've got a pile of money out on a $100 motor

 

[colsan]

Re: What year is my 4 hp mercury

The merc dealer wants about $560.00 for switch box, so I'd best test every properly first
I like the way you talk! How did you make and use a DVA (I'm pretty handy sort of a guy but not real electrical savvy) ?

 

[bktheking]

Re: What year is my 4 hp mercury

Seaway marine, ebay, want ad on craigslist, these motors are around.

I didn't design it but I built it , works great:

http://forums.iboats.com/showthread.php?t=371144&highlight=build+dva