1978 Mercury ???? hp??????

[rancenoce]

Hello everyone, I purchased a boat a month or so ago. It is a 18ft Laser Bass Boat with a Mercury outboard engine. I was told by the seller the cowling has been repainted and stickered. The stickers say 150 HP Black Max, The title states 150 hp, yet the numbers on the motor itself are 1750. Can anyone tell me a sure fire way of finding out for sure what hp this is short of pulling it apart and measuring a cylinder or something.
Actualy any info on this motor would be great, even is it really a Black Max?

Thanks

 

[carholme]

Re: 1978 Mercury ???? hp??????

Do you have a serial number?

Gerry

 

[rancenoce]

Re: 1978 Mercury ???? hp??????

Yes, it is on the data plate yet that is all the info I have. It is 5080515.
And thank you for the response.

Rance

 

[carholme]

Re: 1978 Mercury ???? hp??????

Rance;

That s/n for a 150 comes up as:

V-150 6 4868998 1978
V-150 6 5129480 1979

from here:

http://www.outboard-boat.com/index....50:outboard-model-numbers-and-years&Itemid=53

Because 1979 begins with a s/n greater than yours, it is a 1978

Parts Listing:

http://www.crowleymarine.com/mercury-outboard/575.cfm

90-861333 SERVICE MANUAL $71.43
Notes: (S/N 5464485 and below)

Gerry

 

[rancenoce]

Re: 1978 Mercury ???? hp??????

Thank you for the info, unfortunately I did find those charts and that serial number also falls under the same year (1978) as a 175 hp, that is part of my problem.
I do thank you very much for your help. If I am looking at it the wrong way just let me know.
Also where can one find the model number?

Thanks again

Rance

 

[carholme]

Re: 1978 Mercury ???? hp??????

Rance;

Can provide me with the P/Ns of the carb?

Gerry

 

[Faztbullet]

Re: 1978 Mercury ???? hp??????

Look above where spark/throttle arm is mounted. The older engines had HP stamped into crankcase half. If its a 5 its a 150, 7 its a 175, 2 is a 200. They did this up till about 1988...

 

[rancenoce]

Re: 1978 Mercury ???? hp??????

The carbs have WH 7-1, WH 7-2, WH 7-3. Also 1374-5427, MERCARB.

rANCE

 

[rancenoce]

Re: 1978 Mercury ???? hp??????

I looked all over where the arm is located and only see the cylinder numbers and a number 1 with half a triangle around it on top of the engine. I did look at night with a flash light though, may have better luck tomorrow.

Thanks for the info.

Rance

 

[carholme]

Re: 1978 Mercury ???? hp??????

Rance;

Having a difficult time without an engine in front of me. Here is a link to the parts list for the 175 for your s/n. Looking through both of them, it may help you determine what you have.

http://www.crowleymarine.com/mercury-outboard/586.cfm

What numbers on the motor are 1750 which you talked about in your first post?

Though I know the probability is very low, the start solenoids from the factory were different designs and there are clear pictures of them in the parts listings. What are the odds of the solenoid being original after 30+ years but if the any of the previous owners were religious in ordering parts directly from the manual, who knows.

Gerry

 

[Faztbullet]

Re: 1978 Mercury ???? hp??????

Wh7 carbs are 175 carbs. The 150/175 2.0 liter motors use all the same parts except block and carbs and some stator differences(amps and thickness)

 

[rancenoce]

Re: 1978 Mercury ???? hp??????

The starter solenoid matches the 150hp yet as you said it could have been replaced. The numbers (1750) were read off of the cover that mounts on two bolts too cover the carbs.

 

[rancenoce]

Re: 1978 Mercury ???? hp??????

The choke solenoid matches the diagram for 1978 175hp and none of the diagrams for 1978 150hp. The engine itself seems to lean towards 175 and the documentation leans towards 150. I am sure the markings and parts on the motor should be correct and the numbers could have been messed up at some point in the past. Sadly still not 100% convinced.

 

[carholme]

Re: 1978 Mercury ???? hp??????

rance;

I don't know if this will help but the blocks have different P/Ns

For your s/n the 150 is 858-8133A3
and 175 is 858-8134A3

I don't know if you can find anything like that embossed on the blocks.

Gerry

 

[rancenoce]

Re: 1978 Mercury ???? hp??????

Found them I think. It is 858-6283. It is located just below the right (looking from the back of motor) cylinder head on the block, it also has the number 380 within a circle.

 

[carholme]

Re: 1978 Mercury ???? hp??????

Rance;

Sorry, they don't come up anywhere that I am familiar with. I'll keep trying.

Gerry

 

[rancenoce]

Re: 1978 Mercury ???? hp??????

That is ok, I have learned a great deal and that is good. It will be figured out some how, just want to know for sure. Time to head to work now you all have a good rest of the day and thanks again.

Rance

 

[Faztbullet]

Re: 1978 Mercury ???? hp??????

I am pretty positive that the 1750 block. It will be a vertical reed motor,choke plates on carbs,fine tooth flywheel,heavy 5250 rods, idle stablizer above carbs,large barrel harness(14 pin)