1973 Johnson 115 HP help

[bird391]

On Saturday I am going to purchase a 1973 115 HP Johnson for $750.00. I will be putting it on 1978 17 ft.Lund Sirius bow-rider. I am fairly new working with marine motors so when I go to get this motor I am wondering what i should be looking for as far as potential problems. I was told that the compression is 120 in each cylinder, I was told all controls come with it, I was told trim and tilt work, I was told engine runs great but has been sitting for a couple years. The guy I'm buying from said it runs great but may need to be ran for a bit to clear it out? What should I be worried about here? Basically this is my first used outboard I will be buying and wanna make sure I'm buying something good. I have heard a lot of good things about the Johnson 115 and that's why I've decided to buy one. I should also tell you I live in Wisconsin and am wondering if there is anyway I can tell if the boat has been stored properly in the winter. ANY advice anyone has for me would be greatly appreciated!!!

I have to say this is my second post on Iboats and the responses I got to the first post were VERY helpful. THANK YOU IBOATS and everyone who has helped me.

Also one last thing. I may need a new cowling but would like to use a newer one. Will a newer Johnson cowling fit on the 1973 motor? And by new I mean anything newer than 1973.

Jason

 

[oldrudedude]

Re: 1973 Johnson 115 HP help

Would be good if you could test it in the water, otherwise a lot of unknowns: condition of impeller, carbs, ignition, lower unit, etc.

 

[emdsapmgr]

Re: 1973 Johnson 115 HP help

I'd make sure it is a 73 and not a 72. The 72's had electric shift lowers. Verify the compression- as that has everything to do with the condition of the powerhead. 120 compression is good, normal for that engine-it does run higher than the later crossflows. Pull the bottom drain plug on the lower unit and check for water in the oil. Any carbed engine can have dried fuel in the carb passages if not properly stored-esp with today's fuels. I'd ask for it to be started to insure the carbs don't have dried fuel in the passages affecting how it runs/idles. Worst case, you will need two carb overhaul kits. Check to see that all 4 plugwires have hot spark. Plan on putting a new water pump impeller in it once you buy it so you know that is ok before your first boating outing. If you have a laser temp gun, make sure the powerhead comes up to normal temps (140-150) at idle so you now the vernatherm is ok. The original fuel hoses on this engine were not made to handle today's ethanol fuels and will deteriorate over time. You should plan change all of them, as the replacements will handle current fuels. Tilt/trim was a nice, worthwhile option on this engine. Cowlings are interchangeable, but did change sometime in the late 70's. Some cowls are rounded on the back side, the later ones have a flat face down the middle of the back side and they are not interchangeable, so check their appearance before purchasing.

 

[ezmobee]

Re: 1973 Johnson 115 HP help

^^^^ excellent advice. Given you are paying $750 for it I would definitely take the advice above and do a compression test on it and check the lower unit. I just recently sold a boat with a '73 85 on it. It was a great motor. We used it for 5 years with little issue after dumping some money into it to "awaken" it after a long layup. 2 words of warning are....if it does not currenly have power tilt & trim, forget about trying to find a used unit to upgrade it. Those years TnT unit go for a zillion dollars on ebay. Not until post '78 do they get more realistic. If you really want TnT, a CMC aftermarket unit is a better investment. Also, I am pretty sure if you ever have to replace the lower unit on a '73 it's going to run you quite a bit more than a '78 or newer unit. Definitely a great motor though.