1969 Johnson 115HP Video: Carb loading up? Check it out!!

This is a 1969 Johnson 115HP. Compression is 125psi in three cylinders, about 118psi in cylinder #1.

My motor "loads up" when at idle speeds. Likes to stall out when I bring her down to an idle and then try to take off again. Then sometimes hard to start or keep started. Once you get it started, it once to die as soon as you give it gas. So I've had to manually move the throttle arm forward to get it past the stall phase and moving again. Not sure what the initial movement of the throttle is doing (it's opening something, but not really moving the idle arm until you move the throttle further forward), but if I move the arm forward manually, it quickly jumps forward and the boat is on plane again.

Last night, it was idle a little rough in my drive way, so I adjust the slow speed all the way to left, which turned the 4 adjustment screws out about a 1/2 turn. This smoothed it out. The linkage to the knob on the front of the motor and the adjusments arms is not intact.

I checked the fuel pump for leaks. It appears good. There was no fuel coming out of the vacuum line that attached to cylinder #1 when I pump the snot out of the fuel tank.

So, here is what I found: https://www.youtube.com/watch?v=d6S2uBgtn6o&feature=youtube_gdata_player

Is this normal? The top throttle plate is dry as a bone. The bottom one is spitting fuel out of the intake. There is gas all over the throttle plate and gas being ejected out towards the camers. But the top intake is bone dry.

Is this a problem? If so, what is wrong? Any ideas fellas? BTW, this old motor is on the original boat....I restored this 1970 Starcraft V180 about 8 years ago. New stringers, transom, floor, and interior. The rest buffed out and cleaned up. She's a beauty!!

Thanks in advance.
Steve

Re: 1969 Johnson 115HP Video: Carb loading up? Check it out!!

It appears you may have a float problem on the bottom carb flooding the bottom cylinders. That would cause load-up issues at idle. Running #1 dry is killing that motor, probably why compression is low on that cylinder. If you haven't rebuilt those carbs in a while, now is the time to do it.

Re: 1969 Johnson 115HP Video: Carb loading up? Check it out!!

If there is plenty of fuel in the carb (because of a potential float problem) and there is so much in there that gas is spitting out of the intake....then why would cylinder #1 run dry?

This may sound like a silly question, but I'm just not getting it? Or is the float perhaps stuck in the up position or full position and this causes the fuel to shoot out the intake instead of into the carb?

Re: 1969 Johnson 115HP Video: Carb loading up? Check it out!!

In the lower carb, the float is low allowing more fuel in than is supposed to there overflowing into the throat. In the upper carb the float appears to be high , not allowing enough fuel in. Each carb is fed separately. Also you may have a clog in the fuel line to the upper carb. You don't say where you are, but if you any ethanol based fuel and have not replaced the fuel lines with ethanol resistant fuel line, you may have a chunk of the fuel line stuck somewhere.
BTW the float is connected to a valve, when the bowl needs fuel the float drops opening the valve, when full the float rises closing the valve.

Re: 1969 Johnson 115HP Video: Carb loading up? Check it out!!

I'm in Angola, IN. For sure, I have used Ethanol enriched fuel in my boat. No, I have only replaced one small fuel line section....a piece that goes to the bottom carbs because it cracked near the nipple so I replaced it with some Aeroquip hose that is oil and fuel safe. I'll have to look at her better and see what I find.

So, should there be some fuel on the choke plates on the upper carbs? You seem to think that the upper plate being dry means that those carbs are running lean. I'm freaking confused.

The bottom carbs are spitting gas = too full The upper carbs are dry = running lean.

So do I want somewhere inbetween? Or should both top and bottom carbs look like the upper ones?

Anyone can call me anytime they want if talking is better than typing: 952-288-3989

Steve

Re: 1969 Johnson 115HP Video: Carb loading up? Check it out!!

A properly adjusted carb will actually appear dry even though there really is an invisible film of fuel flowing across the plates.

Re: 1969 Johnson 115HP Video: Carb loading up? Check it out!!

I've never taken apart an outboard carb before. A few small motor carbs (lawn mower, scooter, etc.) but never something like this. I'm pretty sure I can figure it out.

Do you think it would be a bad idea to unplug the fuel line, run it out of gas, and use a long-neck dropper to fill the carb with 100% seafoam through the throat and just let it sit for a few hours or a day? Or maybe a different solvent? Just curious.

Should I go ahead and buy two sets of carb rebuild kits before I even start this? If so, can you recommend any?

Re: 1969 Johnson 115HP Video: Carb loading up? Check it out!!

You probably won't have any trouble rebuilding them yourself, just take your time. Seafoam soaks don't get the job done right. The carb kits are available right here on iboats, sierra kit 18-7046 about $15 each. You need two. Be careful removing the choke and throttle links and you might get away without doing a link and sync, even though doing it isn't the worst idea. If you don't already have it, get the OEM service manual, it'll save you in more ways than you can count.

Re: 1969 Johnson 115HP Video: Carb loading up? Check it out!!

Alright. I'm gonna give it a shot. Just for giggles, over my lunch break, I ran my carbs dry and filled them with Techron. I'll start them up when I get home this afternon.

Re: 1969 Johnson 115HP Video: Carb loading up? Check it out!!

The problem with starting the motor on pure techron is there is no oil in in, as bad as lean run. Also, you need to fix the lack of fuel to the top carb.

Re: 1969 Johnson 115HP Video: Carb loading up? Check it out!!

I'll make sure to put some gas/oil in the carb before I start it and re-prime the fuel system with fuel. It should be okay.

This motor has run just like for the past 4 years. No much use. Maybe 20 hours a year. It's just a pain in the *** to deal with. I'll let you know how my "soak" turned out and how my carb clean/rebuild goes.

Plus, for 43 years old and having 118-125 psi in this big ol' 115HP....is pretty good I think. Maybe it's not.

What is compression on this motor new?

Re: 1969 Johnson 115HP Video: Carb loading up? Check it out!!

No doubt, the compression numbers are good. At this point though, if you don't fix the top carb problem, it might not see 44. When was the last time you changed the impeller on it?

Re: 1969 Johnson 115HP Video: Carb loading up? Check it out!!

It's been a few years. Maybe 60 hours or so of use.

I hate how these motor spit the water out the exhaust. I wish it had the "pee stream"....so you can actually see what's going on.

I am always suprised at just how little of water spits out of those two exhaust ports. It sure doesn't seem like much to me vs. the pee-stream. why does everyone hard on changing the impeller? What goes wrong with them? Do they go bad easily or something?

Re: 1969 Johnson 115HP Video: Carb loading up? Check it out!!

Typically they only last two years before the risk of them blowing apart. What you may not be realizing, you said its been this way awhile, is that not only is fuel not getting to the top carb but no oil has been getting to the upper crank,con rods,etc either.

Re: 1969 Johnson 115HP Video: Carb loading up? Check it out!!

Obviously some oil has been getting up there!! The motor runs on all four cylinders, but I get your point.

Something I came up with.....do these motors have reed valves? I was thinking maybe a faulty reed valve would allow fuel to be blown out into the throat like that. Do they have reed valves?

Re: 1969 Johnson 115HP Video: Carb loading up? Check it out!!

Yes, it does have reed valves, but your compression numbers are too good to have a problem with them. I guess I'm a little confused, in your original post you said when you pump the bulb, no gas came out of the line feeding the top carb.

Re: 1969 Johnson 115HP Video: Carb loading up? Check it out!!

I should have explained better. One way to check the fuel pump for leaks is to disconnect the vacuum source to the fuel pump. This rubber hose runs from the bottom of the fuel pump to Cylinder #1. If you disconnect that hose and pump the snot out of the primer bulb, gas will leak out of that vacuum line if there is a rip or tear in the rubber diaphram. Sometimes a faulty fuel pump will cause the stalling/stumbling when at idle (low vacuum). But that's not the case here.

The motor runs decent on all 4 cylinders. It just loads up when it's good and hot and you slow her down. Obviously with the gas spitting out like that in the video, the gas is collecting in the throad and when I open up the carb again, it bogs down and wants to die. Unless I advance the timing quickly with the throttle arm and then she takes off. But that is a pain in the ***.

Re: 1969 Johnson 115HP Video: Carb loading up? Check it out!!

Give me a ring RockyRude: 952 288 3989

Re: 1969 Johnson 115HP Video: Carb loading up? Check it out!!

Maybe I'm over thinking this, but isn't the only way that there is gas blowing out of the carb is the reeds aren't functioning properly on the compression stroke?

Re: 1969 Johnson 115HP Video: Carb loading up? Check it out!!

A buddy of mine who is a certified boat mechanic said he's rebuild my carbs for $40. Cool.

He cleaned the living day lights out of them. And re-installed. It's still spitting fuel out the throat on the bottom assembly. Hmmmm??? Any ideas?

He said the reeds looked decent. He even blow smoke in the combustion chambers through the spark plug holes and no smoke came out the carb.

He's gonna have a friend look at it who swears that the float needs adjusted. The original mechanic said they were in spec.....but it doesn't hurt to have someone else look at it.

Any ideas fellas?