1975 115hp johnson new time base ??

[elf714]

looking at this 1975 johnson 115 for sale locally, seller says its hard to start, extended crank and excessive choking to get started - colder the weather - harder to start. mechanic told him it needs new time base ?? never heard of this, wonderin if someone could tell me about this before i buy this motor blindly. seller says it runs great after ya gets it started... thanks for the help

 

[scrampbell]

Re: 1975 115hp johnson new time base ??

I'm no expert, but doesn't seem like timer base issue to me. You may already know this, but those are expensive too, ~$300 for my 1984 70hp. Best thing to do would be to get a peak voltmeter and test the timer base. Peak voltmeters are also expensive, so if you can borrow one from advance auto parts or something, that's going to be your cheapest solution. Service manual will give you the test (library may have a usable manual).

You can also check the spark at the cylinder on a spark tester to get a general sense of the electrical system. You should test for spark at 1/2 inch gap and get a thick blue spark on all cylinders. Anything less, and you probably couldn't rule out the timer base. If you're going to be working on motors, you should really have a spark tester with adjustable gap.

Just going by what you've said, it sounds more like fuel delivery issue. Ie, weak fuel pump or failure to fully prime. Maybe even partially blocked or cracked fuel lines or fuel line fittings. If it runs fine once you get it started, then you can at least feel confident you're not buying a motor with a cracked head or one that just overheated or something. Make sure it runs fine under load and not just on the muffs.

Please someone correct me if I've got anything totally wrong.

 

[elf714]

Re: 1975 115hp johnson new time base ??

thanks friend, the info you provide is somewhat same to my thoughts..... the part is 300.00 at dealer, seen around 250.00 ebay - new, good is it's still available. seller says carbs were off also during the hunt to fix the problem , dealer mechanic did the work. i'm in belief that some testing should be done, adjustments/syc should be check'd, spark quality, etc., before i take off on a wild goose chase....... thanks for the input, i'm go look at this motor around 6 tonight, hopeful of a good compression test and maybe spark test also, wish me luck. thanks again for the input.

 

[ezeke]

Re: 1975 115hp johnson new time base ??

The timer base on the 1975 is adjustable and sometimes needs only that.

The engine always needs to have working choke plates that will stay fully closed while cranking, and it needs a fully charged, powerful battery to turn the engine at the minimum cranking speed of 250 RPM, preferably 300 RPM.

The most important things to check before purchase are the compression and spark, both of which should be done with all of the spark plugs removed.

 

[elf714]

Re: 1975 115hp johnson new time base ??

thanks for the info, bought it, all looks really good, seller stated dealer has replaced the time base with no change in how it starts, along with the carb rebuilds that also did nothing for the hard start, i gotta buy a manual and will now have what looks like a winter project...... do see one concern - tag on the motor says timing = 24 degrees...... this is a stick-on type sticker, thanks for the input . i'll be talkin at ya again soon i'm sure.

 

[ezeke]

Re: 1975 115hp johnson new time base ??

The sticker is correct; full throttle spark advance is 24 degrees. There should be no reason to change the timing unless you moved it.

The cold start is easier when the choke plates are fully closed, the warm-up lever is fully raised, and the battery is fully charged.

The ignition will not perform below the minimum cranking speed of 250 RPM, which requires a fully charged, powerful battery.

For all-around use, you will get the best results using Champion QL77JC4 spark plugs.

 

[mrcj001]

Re: 1975 115hp johnson new time base ??

The choke plates on those crossflows must shut very tight when you activate the choke. Make sure that they are adjusted properly.

 

[elf714]

Re: 1975 115hp johnson new time base ??

got it home, put on and replaced the throttle cable - was super tight, adjusted the choke solenoid - sooooo far outta adjustment, check'd plugs and compression - very nice - 130 almost exact all 4, filled the half barrel with water and figured it was time to see how bad things were....... well the hard start condition doesn't seem to be a problem - fired right up within a couple seconds, has a rather high idle with lever in the up position , normal idle also sorta high ( nope, no tach hooked up yet ), didn't overheat, ran in the barrel for almost 30 minutes, feelin really good right now. tomorrow gonna head to the ramp, just some short run time and maybe a short cruise. 16' sylvan aluminum open fishin. i didn't see any adjustment screws on the carbs - so at this point i assume it's a none adjust carb setup..... still lookin for a manual, so i'm pretty much wingin things now. i'll let ya know how today works out. thanks for the help and input. really appreciate ..

 

[ezeke]

Re: 1975 115hp johnson new time base ??

The carburetors have all fixed jets, so the only adjustment is to the linkage to make sure that the throttle plates are fully closed at idle position and synchronized through the whole ranger of motion. When the control arm is fully froward, the throttle plates should be perfectly horizontal or WOT.

 

[elf714]

Re: 1975 115hp johnson new time base ??

no adjustments, thanks ezeke, solves that question, out on river today, started right up at the ramp, idled out to the river, trimmed her down all the ways, full throttle and away she went. no tach, no figures for ya. backed off throttle and let her cruise for 45 minutes . back to idle, back to full throttle, several times. runs great. only issue - idle kept getting higher and higher as time went by. shut down, no crank, fixed loose wires at solenoid, fired right up again. idle high enough to put ya in yer seat if your not expecting the shift..

 

[elf714]

Re: 1975 115hp johnson new time base ??

ezeke, i've only replaced the throttle cable, was looking at the closed throttle position so haven't check'd the full throttle plate positions. i'd be real happy if it'd just run as good as it did today everyday...... with the idle speed reduced.... hahahhaaaaaa.... thanks for the info,,,, i'm still without a manual so the info is appreciated.

 

[elf714]

Re: 1975 115hp johnson new time base ??

115esl75e, model j4322774 (can't make out the last digit), 16 sylvan aluminum v, was 40 merc, what a difference....... 13 x 19 aluminum prop. everything is in really good condition including the prop. was too windy today for any fishin, but the boat ride was great. mid 70's, sunny. beautiful fall day.