1968 40 hp Johnson

[outboards115]

Hi,
I've just got a 1968 40 hp johnson with a seized and bent drive shaft. Can anyone suggest any websights I can get a new drive shaft from? Also how much would one cost, I don't need the exact price, just want to get an idea how much I should spend. If anyone could help me out, that would be great!
Thanks
Will be puting serial/model number up tomorrow.

 

[HighTrim]

Re: 1968 40 hp Johnson

Marineengine lists them at about 150 bucks I think.

If it were me....I would buy a parts motor for under 50, use the drive shaft, and still have alot of good parts left for future issues.

 

[Daviet]

Re: 1968 40 hp Johnson

You can also look in the "Top Secret File" sticky at the top of the page, there is a list of salvage yards there, give some of them a call and check prices.

 

[outboards115]

Re: 1968 40 hp Johnson

Ok,
Thanks, I might even be able to get a parts motor of a similar type for free if I'm lucky.
Will let you know when I get the shaft out from the motor. (the shaft is seized to the powerhead)

 

[outboards115]

Re: 1968 40 hp Johnson

Hi,
Just another question, I tried starting the motor the other day, i mesured the compression wich was 110 in boath cylinders and it had excelent ignition (bright blue spark) so I poored some petrol in the cylinders to see if it would at least fire up for a few seckonds but there was nothing, not even a slight sound of it firing.
Can anyone help?

 

[geoffwga1]

Re: 1968 40 hp Johnson

If you poured petrol directly into the plug holes it was probably drowning the plugs as well as being much too rich.You need to get a spray bottle of proper mix fuel and spray into the carb throat.Hope you're having a nice spring.
geoffwga1.

 

[boobie]

Re: 1968 40 hp Johnson

How did you check your spark ?? It has to fire a 1/4 " open air gap on a spark tester. Spark plugs don't get it.

 

[1946Zephyr]

Re: 1968 40 hp Johnson

A '68 40hp is probably one of the easiest motors to coax back to life. If the ignition system is up to snuff and the carb is in good order, they almost run non-stop. If your coils have been replaced in the past, then it's likely your points just need to be cleaned and re-gapped. If the coils are cracked, then they need replacing. A new set of coils in there will definately do wonders. 110 in both cylinders isn't bad for that motor. They weren't the high compression motor like the '58's were.

 

[outboards115]

Re: 1968 40 hp Johnson

I think the koils are good because when I tern the flyweel over with my hand I get a huge shock. I will test it again some time soon and see it it starts. The carby looks to be in goon condition, when I drained it there the fuel was not dirty at all. I may have flooded the motor but we'll find out soon.

 

[HighTrim]

Re: 1968 40 hp Johnson

You should not get a shock.

Spark plug wires likely rubbing on flywheel/mag plate where they exit.

 

[1946Zephyr]

Re: 1968 40 hp Johnson

Yep. You should only get a shock, if you touch the end of the lead, if you can get your finger inside the boot.

 

[outboards115]

Re: 1968 40 hp Johnson

I also forgot to mention that the millitary used this motor, I think they've put a spark plug protector ovet the lead and boot. The only way i can describe ti is, it has a metal snake skin type thing around the spark plug lead and a metal cup thing with clips in to th keep the spark plug in it, I'll try and get a photo of it. would it have something to do with this problem?

 

[outboards115]

Re: 1968 40 hp Johnson

it had this type of stuff ot the leads
I think the part around the boot was called a heat sheild.
this was the closest "heat sheild" I could find.

 

[HighTrim]

Re: 1968 40 hp Johnson

I would take all that off, it is not needed. It probably tore through the plug wires insulation, so the HT lead is arcing through the shield and zapping you.

 

[outboards115]

Re: 1968 40 hp Johnson

It was zapping me at the plug, I put the pug into the boot then slowly turned the motor over with my hand and it zapped me. But I'll still take the sheild off.