1974 Johnson 135 hp questions

[skylerjshelton]

Hello, i recently acquired a 74 johnson 135 hp. i have a few questions. i took the boat out to see if it runs. i started it up and backed it off the trailer. i put it in forward and when i start to throttle up it dies. it seems to idle fine, but once you give it some throttle it dies. here are my questions
1. what is the fuel/oil ratio?
2. where does the water come out of the motor so i can tell if pump is working correctly?
3. i cleaned carbs out with carb cleaner and now it starts just fine but i havent had on water yet.
4. hooked up earmuffs to it and there seems to be water coming out of a few holes on leg. is that normal.
I would like to be able to see that water is cooling the motor. how hard is it to put a temp gauge on the motor? thanks for your time.
the guy said his son changed the impellor. can i pull lower unit off and look. or do i have to buy new gaskets. or how can i find out if its good. i have a fishing tournament in a week and would like to have it going by then? any help would be appreciated.

 

[ezeke]

Re: 1974 Johnson 135 hp questions

1. 50:1.
87 or 89 US octane to TC-W3 oil better to use synthetic or synthetic blend TC-W3

2. Most of the water goes out with exhaust through the propeller. There are drains at the top of the gearcase and two exhaust relief holes near the top of the midsection.

3.

4. It is easy to add a temp gauge or two, you just need a kit from your dealer. Each sensor can only read one bank of cylinders.

You can remove the gearcase for inspection; there are no gaskets that would normally require replacement.

When the motor dies under load it generally indicates that one or more cylinders are not firing. Conduct a compression test, then a spark test. Compression test guidelines are in the Secret file at the beginning of the thread listing for this forum.

 

[skylerjshelton]

Re: 1974 Johnson 135 hp questions

thanks for all your input, i will check compression and spark today. one question though, i thought it would miss at idle if one cylinder wasnt firing?

 

[ezeke]

Re: 1974 Johnson 135 hp questions

thanks for all your input, i will check compression and spark today. one question though, i thought it would miss at idle if one cylinder wasnt firing?

It will if it's in gear and in the water.

 

[Wishiniwuzfishin]

Re: 1974 Johnson 135 hp questions

Just to add. I have a very similar motor. 1974 115HP Johnson which I just recently acquired. I have been running mine in the driveway with muffs. Mine has water droplets and a fine spray coming out the two upper exhaust relief holes (in the rear of the motor just under the powerhead). I can see it when I'm standing behind the motor but it would be hard to see from in the boat I think. I checked to make sure my warning horn worked by grounding it with key in on position and it beeped but that doesn't actually mean the sensor is working, but at least I know the horn is. I also have water coming out of various places on the lower leg when running on muffs. I've read on here that a water pressure gauge would be better than a temp gauge. Pressure gauge can forewarn you of problems, temp gauge tells you after the problem has happened....just what I've read. I'm thinking of putting one on. I'd like to hear what you decide and how it goes.

 

[Pokertrampp]

Re: 1974 Johnson 135 hp questions

4. hooked up earmuffs to it and there seems to be water coming out of a few holes on leg. is that normal.

I have a 1988 120hp Johnson that does the same thing, It has been that way since I bought it 6-8 months ago but I have had no problems. When I first noticed it water seemed to be coming from everywhere, I thought for sure something was broken, but it turns out its normal.

 

[skylerjshelton]

Re: 1974 Johnson 135 hp questions

ok i took boat to the water today since i cleaned carbs. it started up and idled fine. then if i slowing give in throttle and wait, then give it more, and wait it runs fine. what does this mean. a fuel problem?

 

[emdsapmgr]

Re: 1974 Johnson 135 hp questions

These early crossflows don't have a telltale that indicates the water pump is working. Those water droplets out of the exhaust relief holes are a good indicator on these older models. The thermostat (vernatherm) will open after about a minute on a cold engine. When it opens (and water starts to flow through the block) you will get water droplets out of those holes. A water pressure guage is a nice option. You need to tap a hole in the exhaust cover or the block in order to install a hose barb for the gauge.

 

[ezeke]

Re: 1974 Johnson 135 hp questions

Just to add. I have a very similar motor. 1974 115HP Johnson which I just recently acquired. I have been running mine in the driveway with muffs. Mine has water droplets and a fine spray coming out the two upper exhaust relief holes (in the rear of the motor just under the powerhead). I can see it when I'm standing behind the motor but it would be hard to see from in the boat I think. I checked to make sure my warning horn worked by grounding it with key in on position and it beeped but that doesn't actually mean the sensor is working, but at least I know the horn is. I also have water coming out of various places on the lower leg when running on muffs. I've read on here that a water pressure gauge would be better than a temp gauge. Pressure gauge can forewarn you of problems, temp gauge tells you after the problem has happened....just what I've read. I'm thinking of putting one on. I'd like to hear what you decide and how it goes.

Which gauge is better depends on your goal.

The water pressure gauge can never tell you if the engine is overheating, if the water is passing through the engine cooling passages properly, or, if the thermostat is functioning. It can give you an early warning if your water pump is weakening, which is very important.

The temperature gauge can give you a way of monitoring the actual temperature of the cylinder heads so that you know in advance that something has changed, rather than wait until the temperature switch sounds the horn. When the horn sounds, some damage is probably already done.

You can add a tell-tale and the outlet for the water pressure gauge at the same time. Try these links for more information: http://forums.iboats.com/showthread.php?t=222677

and: http://www.downloadingfiles.co.uk/teleflexfiles/gauges/Outboards.pdf

 

[skylerjshelton]

Re: 1974 Johnson 135 hp questions

ok i added a taletell. and the water pump is pumping fine, so that relieves a few worries. i took boat out yesterday and i cant figure out what the problem is. i go at idle for a while then slowly give it throttle, and eventually it will run WOT for a while, but if i stop and sit for a lil bit, then go again it does the same thing, would this be a fuel problem. here in a couple weeks think im gonna get a fuel pump, carb rebuild kits and new plugs and see what happens after that. what do you guys think.

 

[ezeke]

Re: 1974 Johnson 135 hp questions

Two things:

First, make sure that the throttle plates are synchronized; you will have to remove the air silencer, open the choke plates and watch the throttle plates as they move through the entire range of motion. They should be fully closed at idle (with the warmup lever down) and horizontal at WOT, and perfectly synchronized throughout the range of motion.


Secondly, make sure that the automatic choke has been disabled so that full control of the choke solenoid rests in the operator, using the toggle switch.

 

[emdsapmgr]

Re: 1974 Johnson 135 hp questions

Double check to make sure you have good spark. When you have the engine in the water, and want to speed it up, put an inductive timing light on each plug wire and check for constant spark. This will show weak spark or misfires. If the spark checks out ok, then you know you have a fuel issue.

 

[John442]

I have a 1974 Johnson 135 I just picked it up and the guy swears up and down that it's a 4-stroke motor I'm pretty sure they didn't make four strokes then could I be wrong

 

[racerone]

4 cylinder yes but NOT a 4 stroke !!

 

[GA_Boater]

I have a 1974 Johnson 135 I just picked it up and the guy swears up and down that it's a 4-stroke motor I'm pretty sure they didn't make four strokes then could I be wrong

Asking for help in an 8 year old thread usually means you won't get any because most members ignore old, inactive threads. Please start a new thread if you need more help than racerone gave.

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