1978 150 hp johnson Need Lots of help

[Casperjjt]

Ok here goes nothing but I figure it is worth a shot since ya'll helped get my 63 evinrude running. Just aquired a Cabin Cruiser project from my son it has a 150 hp Johnson 1978. I know the starter is shot so where is the best place to get an inexpensive replacement. next it only seems to fire intermitantly to the plugs. some times all work some times a couple sometimes one bank sometimes the other bank. Where do I start to try and get this motor to breath some life? Note: This motor has probably not been fired up in a good 10 years but does spin freely is there an easy test for coils? is there a way to test the stator? does this motor have points? like I mentioned in my evinrude posts outboards are pretty much new to me But I can follow simple instructions and even more complexed ones when need. was an aircraft mechanic for 10 years so I am not afraid to get a lot dirty this is just my newest project and would love to have it running and floating by spring. any advice will be greatly appreciated.

Thanks in advance

Casper1969

 

[SparkieBoat]

Re: 1978 150 hp johnson Need Lots of help

starter rebuild kits are cheap..you need to get a manual that will help you a lot..also E-bay has some cheap starters. You need a compression gauge, and a spark tester..both available at an auto parts store..you should set the spark tester at 7/16 gap and you should get a thick blue or blue yellow, not light yellow and thin and hit and miss (weak coil).
The next thing to do is compression check. ( see the Top secret file at top of this forum). I would spray some oil into the cylinders and carbs while turning it over since it has been sitting so long..marvel mystery oil is good stuff, but some 2 stroke oil will do.

 

[jonesg]

Re: 1978 150 hp johnson Need Lots of help

You can get the service manual here,
www.outboardbooks.com

 

[Casperjjt]

Re: 1978 150 hp johnson Need Lots of help

You mean having my grand daughter hang onto the end of the spark plug while I crank is not the approved method of checking for spark? (Just Kidding)

any how I will be picking up a spark tester on the first to see what kind of fire I am working with. I am on disability so getting parts manuals extetera will take time any how I don't think a rebuild on the starter is on option 2 of the magnets inside the starter have come unglued and ar cracked down the center and the bushions(brushes) whatever they are called in the end cap are really chewed up. any how is it possible to reglue the magnets and sand the cracked area smooth then file the brushes flat again to at least us this starter for trouble shooting I know it would be by no means a permanant fix.
Just trying to get out a head of the curve with out tossing out a lot of money at first like I said I am on disability so money comes once a month and is tight at times. any how Like I said This project was given to me and the boat, motor and trailer all have clear titles so I figure even if I get 500.00 into the engine to get it roaring I am still making out like a bandit where else would you get a 150 hp for that cheap thanks

Casper1969

 

[jonesg]

Re: 1978 150 hp johnson Need Lots of help

if you get the manual first it will explain whether you can rebuild the starter.

 

[emdsapmgr]

Re: 1978 150 hp johnson Need Lots of help

If it's been 10 years, you should put in a new lower unit water impeller. Fuel may have dried up in the carbs over the years, so you may need 3 carb overhauls also. The fuel hoses (if original) are not compatible with today's ethanol blend fuels. They should be replaced, or they will deteriorate and loose/deteriorated hose material can get into the carb jets, restricting fuel flow. When you get it started, make sure you check/monitor the cyl head temps closely, as the thermostats are old, too.

 

[mikesea]

Re: 1978 150 hp johnson Need Lots of help

hey bud,I hear you on the disability and tight times.No reason why you cant try and tackle the starter on your own,JB weld would probably hold the magnets ok,but depending how badly chewed they are ,you might not be able too,I have pulled many starters apart and many times a good cleaning did the job.I worked for a guy yrs back and we were able to buy new brush caps,I dont know where the outlet is.You definatly need to pull the carbs off and at minimum clean good,but given the age,a rebuild is likely in order.You can buy the carb kits from IBOATS store,the prices are great AND since you get free advice here,I like to buy here.Ebay would be a good place to find a used starter,most outboard salvage places will have them ,though marine stores get good $$$ for anything.The waterpump needs to be serviced ,at minimum an impeller is in order,I agree with the idea of changing hoses.if you do the work,barring anymajor breakdown after she fires,you should be able to get it goin for far less than 500,intermittent spark could very well be just dirty ,corroded connections,be sure all plug connections are clean and free of corrosion,you mention the starter being bad,well,if that eng cant crank fast ,it wont produce spark,should you have good crank power,disconnect the main red harness plug,remove all spark plugs,hook up your spark tester and jump positive to starter direct,you should get spark,if you then hook up the red plug and crank not getting spark,you may have a bad key switch or a harness problem,the key sends ground to the powerpack ,which kills eng.I believe your eng has 2 powerpacks,one on each side of the block that connects to the coils,be sure all connections to coils and packs are clean and tight,if you miss spark on 1 or 2 cylinders,check the coils for ground and connections,you can also swap coils around to known good spots,een though you may have different color stripes on your coil wires (small wires)you can still wsap,BUT be sure they feed the correct cyl.or you will get misfire.you can also swap the powerpacks for testing.

 

[Casperjjt]

Re: 1978 150 hp johnson Need Lots of help

If it's been 10 years, you should put in a new lower unit water impeller. Fuel may have dried up in the carbs over the years, so you may need 3 carb overhauls also. The fuel hoses (if original) are not compatible with today's ethanol blend fuels. They should be replaced, or they will deteriorate and loose/deteriorated hose material can get into the carb jets, restricting fuel flow. When you get it started, make sure you check/monitor the cyl head temps closely, as the thermostats are old, too.

never thought of the fuel lines but will replace them and the carbs have allready been rebuilt and cleaned but not adjusted.

Next question My son just aquired me a 72-73 150 hp Johnson it supposedly runs but has a bad lower unit i don't know if this second motor has a title or not will the odds and ends parts interchange between the 2 motors or will the lower units swap over if the 72-73 does run and has a title?

casper1969

 

[Casperjjt]

Re: 1978 150 hp johnson Need Lots of help

well after trying to find out if the starters on the 72 and 78 are the same I discovered johnson doesn't list any 150 hps prior to 1978 maybe the guy got the year wrong maybe the horse power wrong or maybe I got lucky and will be haveing a lot of spare 150 parts well I will update everyone tommorow once the engine arrives and is in my hands physically suppose to be tommorow early eveing late afternoon

casper1969

 

[emdsapmgr]

Re: 1978 150 hp johnson Need Lots of help

The first year for the OMC V6 was 1976. The good thing about these crossflows is that many parts are interchangeable, such as the starters.

 

[Casperjjt]

Re: 1978 150 hp johnson Need Lots of help

well the spare Johnson never showed up today Hope the deal my son made didn't fall through any how it may just be a work week thing and timing who knows I am gonna give it till saturday eveing to show the my hopes of spare parts will be pretty much gone in the mean time my wife and I are gonna try and patch up the bad starter at least temporarily to try and get enough rpms out of this motor to power the ignition and do some further testing so we can ask further questions. we will keep ya'll updated over the next few days

casper 1969