Johnson 70HP Leaking Fuel

[kshays]

Looks like it does not even have this (18-0975-9 gasket) from the carb and the air intake!

[kshays]

The bottom elbow connector I found last night is cracked and fuel is spraying and leaking from it.  I did not notice this until all the lines/wires was moved out of the way.  Trying to find the ID of the elbow connector to see if I can purchase a brass one for now.  

 

Solenoid leak is fixed also.

Carbs were taken back off and float adjusted to 33mm on each one.

Been raining here past few days so not had much of a chance to do anything to it besides that.

 

ty,

 

kevin

[Way2slow]

Are you saying you done put carbs back on without the base gasket. 

I was going to suggest if you check the reeds for blow-by and they are good, you might try opening the low speed mixture about a turn, if it's adjustable, because a lean spit will make it do that.  However, if there is no base gasket and the carb is sucking air between it and the intake, that could account for the lean spit.

[kshays]

Hi Keith,

 

I put them back on without the air silencer gasket.  #33 on this link.

http://www.marineengine.com/parts/johnson-evinrude-parts.php?year=1986&hp=70&model=J70TLCDC&manufacturer=Johnson&section=Intake+Manifold

 

I have the gaskets #30 from that link on all the carbs which was new in the kit.  I do not know if mine are adjustable or not.  Is it the screw on the bottom of the carb?

 

Ty,

 

Kevin

[Way2slow]

No problem there.  Go to the link you posted and go to the carburetor, item #6.

 

These can not be adjusted sitting in your drive way, other than maybe turning that bottom one out a turn or so to see if it quits spitting fuel.

 

The "proper" way to adjust these is to take it to the lake, run around a few minutes to get the engine warm, then you can get some place to park it or you can safely get on the back without a wake knocking you off and let it idle in gear.  Idle speed should be around 700 rpm in gear.  It can be a little higher if it doesn't bang going in gear, or a little lower if it will maintain a steady idle.  Turn the mixture screw in until it starts running rougher, then back out to it's smoothest point, do all three, then go back a double check each one. 

A couple of things, the link and sinc should be done, and take the time to get the carbs sync'ed perfect.  All three butterflies closed at idle and all three start to open at the same time, precisely the same time, not almost.  After the link and sinc is done, and everything is exactly where it's supposed to be, DO NOT use the stop screws to adjust the idle.  Use the timing advance rod between the linkage cam and the timer base.  You only want to change the idle timing, not open the butterflies in the carbs. 

Now, after adjusting the mixture and getting them where it idles great, and the first cool morning you go out and it wants to lean spit (that's the cough they give and act like they want to shut off) even after a couple minutes high idle warm up, open each of the mixture screws about an 1/8 of a turn each.  If it still wants to spit, try another 1/8 turn each.  When you get it where it idles good on cold mornings, it may be a little rich next summer, but usually not enough to need to lean them back down again. 

[kshays]

Will do Keith.  I will probably try early next week so it will not be so crowded at the lake.  That's some good information there you provided

 

Some people would have already taken it to a shop, which is probably easier, but does cost a lot of money and I would actually like to learn a few things so I can do this myself in the future.  Only thing is, like anything else you have to get experience and having someone to guide you and give you advice is greatful!

 

Thanks Keith.

 

Kevin

[kshays]

Took it out while ago, but did not have much luck.  Started fine and idle'd fine for the most part on dry land with the muffs on.  Got to the lake and made it past the buoy's and got to plane then sputtered and died.  Took forever to just get it started again so we loaded it back up and headed home.  When I got home put the muffs on and started right up again.  Let it run for 10 minutes or so and never missed a beat, but I did notice the fuel filter never got up to the level of the hose to the carbs though.  Just thought I would give you an update before I tried those test's to perform.

 

Thanks,

 

kevin

[Way2slow]

About the only thing you can trouble shoot on the hose is a dead cylinder.  About 2,000 rpm is the max you should rev one without a load on it and at that, you are usually not even opening the carbs, that's nothing but timing advance.

After it died, did you pump the primer bulb, if so, did it get firm within a couple of squeezes?  The next time, have someone with you and try squeezing the primer bulb as you start getting up on plane and keep squeezing it for a little after you are up on plane.  You should be able to feel some pressure as you are doing this, if not and it feels like you are just pumping an empty bulb and the motor dies, you have a pickup problem between it and in the tank.

If it runs good while you are squeezing it and then dies shortly after you quit, try squeezing it again and see if it feels like it's moving gas and it should get firm again after several pumps.  If so, you have a fuel pickup or delivery problem with the fuel pump.  While in the driveway, take the cover off, and pump the primer bulb until firm and hold that while you look for leaks.  If there are any air leaks that's letting the fuel pump suck air between the primer bulb and pump, they will leak gas when you are holding pressure on the primer bulb.

You did get the hose back on the pulse valve good, if you took it off.  If not, the fuel pump may not have been pumping enough.  As the piston on the cylinder the pulse valve is connected is coming down, it's pressurizing the crankcase, and that valve is sending that pressure to the fuel pump diaphragm, once it clears the intake ports, that pressure is released and the spring on the diaphragm pushes it back the other way.  That's how the pump pumps fuel. 

 

[kshays]

3 hours ago, Way2slow said:

About the only thing you can trouble shoot on the hose is a dead cylinder.  About 2,000 rpm is the max you should rev one without a load on it and at that, you are usually not even opening the carbs, that's nothing but timing advance.

After it died, did you pump the primer bulb, if so, did it get firm within a couple of squeezes?  The next time, have someone with you and try squeezing the primer bulb as you start getting up on plane and keep squeezing it for a little after you are up on plane.  You should be able to feel some pressure as you are doing this, if not and it feels like you are just pumping an empty bulb and the motor dies, you have a pickup problem between it and in the tank.

If it runs good while you are squeezing it and then dies shortly after you quit, try squeezing it again and see if it feels like it's moving gas and it should get firm again after several pumps.  If so, you have a fuel pickup or delivery problem with the fuel pump.  While in the driveway, take the cover off, and pump the primer bulb until firm and hold that while you look for leaks.  If there are any air leaks that's letting the fuel pump suck air between the primer bulb and pump, they will leak gas when you are holding pressure on the primer bulb.

You did get the hose back on the pulse valve good, if you took it off.  If not, the fuel pump may not have been pumping enough.  As the piston on the cylinder the pulse valve is connected is coming down, it's pressurizing the crankcase, and that valve is sending that pressure to the fuel pump diaphragm, once it clears the intake ports, that pressure is released and the spring on the diaphragm pushes it back the other way.  That's how the pump pumps fuel. 

 

After it died we checked the primer bulb and it was still hard.  I will keep that in mind when we take it out in a day or two.

 

It does fill the fuel filter with gas after squeezing a few times each time we try.

 

I did the test to check for leaks by holding the primer bulb while someone else checked for leaks.  Could not see anything, but I am going to check tomorrow again.

 

I used a hose clamp on that fuel line and hopefully it is on good.

 

** Update.

Checked primer bulb a few minutes ago and it was still hard.  Fuel was still in the fuel filter.  Tried to start and would just crank and crank.  Son-in-law went to look at the fuel filter and moved it somewhat and it fired up.  Do you see anything wrong with this type of fuel filter?  Right now it is actually sitting more of a diagonal than horizontal.  Would that cause issues?  Also I need to find a way to check rpm since the rpm gauge on the dash does not work (lol).

 

Thanks Keith, much appreciated!

 

 

[Way2slow]

The next time it won't start, Have a squirt bottle of premixed gas handy and the air silence off or where you can easily pop it off.  Before touching anything, give each carb a shot of gas and see if it start right up.  Just trying to make sure it's a fuel problem, because just moving the fuel filter should have had an effect on it, and he may have moved a wire making a bad connection when he moved the fuel filter.  You might want to put a piece of tubing or coupling in the place of the fuel filter temporarily just to make sure it's not being too restrictive.  Need to make 100% sure it's a fuel problem and not an electrical/ignition problem.

[kshays]

5 hours ago, Way2slow said:

The next time it won't start, Have a squirt bottle of premixed gas handy and the air silence off or where you can easily pop it off.  Before touching anything, give each carb a shot of gas and see if it start right up.  Just trying to make sure it's a fuel problem, because just moving the fuel filter should have had an effect on it, and he may have moved a wire making a bad connection when he moved the fuel filter.  You might want to put a piece of tubing or coupling in the place of the fuel filter temporarily just to make sure it's not being too restrictive.  Need to make 100% sure it's a fuel problem and not an electrical/ignition problem.

Gotcha, completely understand and makes perfect sense.  Ty

 

kevin

[kshays]

Update:

Replaced the fuel filter with a clear hose temporarily to see if it's being restricted.  Tried to start the motor and it fired up on the second time.  Let it run for 5 minutes, so far so good.  Did the link and sync with the timing advance rod and it seems to idle pretty good.  I still have to get a tachometer to measure exactly how much rpm I am seeing at idle.  Putting in gear forward is much easier now, used to be really hard to push forward.  Tomorrow I am going to replace the clear hose with the fuel filter and see how it goes.

 

Thanks!

 

Kevin

[Way2slow]

Are you doing this in the driveway on a hose or in the water at the lake?  Reason I ask, I think I've mentioned, you can't adjust or do anything with the idle with the motor on a hose.  It has to be in the water at it's normal depth. 

If your boat does not have a tach, there used to be some on ebay that just wrapped a wire around a sparkplug wire for a pickup, they were less than $10.  Problem with those, you had to be at the motor to read it.

 

[kshays]

2 minutes ago, Way2slow said:

Are you doing this in the driveway on a hose or in the water at the lake?  Reason I ask, I think I've mentioned, you can't adjust or do anything with the idle with the motor on a hose.  It has to be in the water at it's normal depth. 

If your boat does not have a tach, there used to be some on ebay that just wrapped a wire around a sparkplug wire for a pickup, they were less than $10.  Problem with those, you had to be at the motor to read it.

 

You know, I remember you saying that now.  At the driveway with a hose.  I think I'm more afraid of taking it to the lake thinking we will have to use the trolling motor to get back LOL.  Hopefully we can go to the lake tomorrow evening and do what we did tonight.  Thanks for reminding me, I completely forgot

 

Ty,

Kevin

[Way2slow]

Something like this. https://www.ebay.com/itm/Wire-Inductive-Tachometer-Tach-Hour-Meter-RPM-Digital-For-2-4-Stroke-Engine-New/193141661172?hash=item2cf823ddf4:g:ztoAAOSwpr9eFXnG

[kshays]

1 minute ago, Way2slow said:

Something like this. https://www.ebay.com/itm/Wire-Inductive-Tachometer-Tach-Hour-Meter-RPM-Digital-For-2-4-Stroke-Engine-New/193141661172?hash=item2cf823ddf4:g:ztoAAOSwpr9eFXnG

good deal, ty for the link!

 

kevin

[Way2slow]

Nothing says you have to get out of sight of the ramp until you feel comfortable with the way it's performing.  Play like a NASCAR drive at Bristol, keep turning left and hang on.

Now, these is another thing you can do if you have the ramp to yourself.  Leave it on the trailer, strapped down good.  Back it in so the motor is at the same water line it would be if it was sitting in the water, and trim it so the anticav plate is level the surface of the water.  That gives you the proper back pressure to do all you checks and adjustments.  Now, I would think twice about standing in the water doing any of this when it's in gear, that prop could make you a few inches shorter. 

Now the fun part, once you are done with all your checking and adjusting, pull the boat back out until the anticav plate is about an inch above the water.  Rev it up to about half throttle in gear, and let it run for a couple of minutes.   If you had a tach, you could go full throttle and watch the RPM and by moving the boat forward or backwards get it so it revs to but not over max rpm.  Just don't hold it at full throttle very long.  Basically, you are using the lake as your dyno.  I do this to set the timing on an engine.  Motors has to be turning over 5,000 rpm to set max advanced timing so I just hook my light up, get everything ready, have someone go WOT for a few seconds while I check it with the light.  Make any adjustments if needed and try it again.  A few seconds is about all you want to hold it like this, so take your reading and back off, adjust if needed, and do it again.

You can run it at partial throttle for several minutes, just watch your pee tube and make sure water is coming out,  You are running at a controlled cavitation so it may try to suck air in the pickup so you want to make sure it's pumping enough water.

One thing, if this is mud/dirt ramp, or if its a short concrete ramp, I wouldn't do this, you will probably make one huge crater for the next guy that backs down, and it can suck crap through the motor.  This thing is moving a hellavalot of water.

 

If you really wanted to do it the RIGHT way, but that's no fun, get you a test prop in the pitch you need and use it.  You can run WOT for several minutes with one.

 

[Rocketvapor]

On 9/30/2020 at 10:39 PM, kshays said:

good deal, ty for the link!

 

kevin

Nice cheap tach for lots of small motors.  Mine will revert to 2 cycle mode on my 1 cylinder 4 stroke.

Oh well, dividing by 2 isn't all that hard

[kshays]

On 10/3/2020 at 12:31 PM, Rocketvapor said:

Nice cheap tach for lots of small motors.  Mine will revert to 2 cycle mode on my 1 cylinder 4 stroke.

Oh well, dividing by 2 isn't all that hard

So true!  Should be here tomorrow so I'll be testing soon.  It also looks like my reply to Keith did not even post several days ago, go figure on that one.  I'll post some updates soon and thanks!

 

Kevin

[kshays]

Took it out on the lake today and from the top to bottom on the plugs the RPM was showing 1100, 600+/- and 450-480 on bottom.  You just wrap it around the spark plug wire 5 times correct?

 

Ty!

 

Kevin

[Rocketvapor]

On mine I set it for 1 Pulse / 2 Revolution but each time I start the motor (a single cylinder 4 cycle) it starts off in 1  Pulse / 1 Revolution (2 cycle mode).  

With a load in the boat WOT shows 9660 to 9680.  Repeatable and steady.  I guess that's really mid 4800's.

I bought a smaller spare prop to get the rpm's up.

Standard prop is 7.4X7, the spare is 7.25X6 (I guess it's for the 2.5hp).

I ran up to 12000+ on the tach and the rev limiter seemed to be cutting in. 

I also lost speed with the smaller prop.  

Maybe the diameter of the 7 pitch prop will wear down to optimum diameter??

The 6 pitch prop is an emergency spare for now.  

 

So, the tach seems to be working, just have to divide by two

Your 2 cycle shouldn't have that issue.  Don't have any idea why you get different reading on different plugs.  
I have a generator with a single cylinder 4 cycle that should be running right at 3600rpm.  

I'll try the tach on it.  

 

 

[kshays]

Ty for the reply Rocketvapor!  I'm still new to the whole boat/outboard motor stuff lol, but learning a lot in the process from you guys!  I don't have a clue either really about different readings or if they are supposed to do that since each one was descending.

 

Got home and found out central heat/air was not responding at all so had to deal with that also, but luckily eat was a heat relay switch or something like that the guy said.  Costed under $100 so I was relieved

 

Ty

 

Kevin

[Way2slow]

A friend of mine bought one of those tachs several years ago, primarily for the hour meter, but he didn't say anything about having to do any math to get the proper reading.  I would think on a two stroke, it would read directly.  As for the bottom cylinder reading lower, either it's not getting a good signal or that cylinder is misfiring and causing the lower reading.

[kshays]

Keith,

 

I'm going to go back maybe tomorrow if nothing comes up and try again.  I did find it off it was descending from each spark plug, kinda made me think I was not doing it exactly correct.

 

LOL, that's all I need is for it to be misfiring

 

Kevin

[Way2slow]

Take the tools to change coils, and if you still get that low rpm on 3, swap coil and wire from #1 with the one on #3 and see if it changes.  If it's low on #3, you might have a timer base or power pack problem.  To trouble shoot that you will need a good multimeter and a DVA.  DVA is a module that you connect to the multimeter and gives peak voltage readings from the outputs of the timer base and power pack that feeds the voltage to the coil.  Now, if you have a very good voltmeter that will read peak voltages, you don't need the DVA.  Just understand, the peak you see on most meters is just a function that stores the highest RMS reading, it is not Peak voltage of and RMS voltage.  For instance, an RMS voltage of 120VAC is 160 something Peak voltage.

We also might getting over you head in your trouble shooting or you are about to learn a hellavalot more than you ever wanted to.

The DVA is nothing but a diode, capacitor and resistor connected to a couple of leads to plug into the meter and a couple to take the readings with.  You can do a search and probably find a DYI diagram.