Carburetor needs cleaning...2002 30HP Johnson

My beautiful 30 HP Johnson won't idle, but runs great at 1/4 throttle and higher. I need carb cleaned but am looking for a service manual....any leads?

If no leads on this, maybe I can get some step by step instructions from someone who has done this? This would be greatly appreciated! Thanks in advance!

Well, I will jump in here I guess.
To tell you the truth, I would try the easy fix first. See if it works. If not, go thru the whole carb.

Easy fix....go to shop2.evinrude.com, select Johnson, and drill into the parts pages til you get the carburetor drawing up.
Notice reference number 9. It is a jet located in the stbd side of that plastic top plate.
Take a can of spray carb cleaner with a straw, and while running, even above idle if needed, stick that straw directly into that jet, and spray liberally. Spray about half the can, not at once, but kinda intermittently, as the engine will falter and try to die. Let it catch back up, and spray some more.

That will shoot carb cleaner directly into the idle circuit passages, and MAY help the situation.

Next, you have an idle adjustment needle reference number 18. Try opening that up 1/2 turn at a time or so, remembering the turns so you can go back if you need to.

If above fails, report back for more detailed carb cleaning instructions...what to look for, tips, tricks, etc.

Good answser Daselbee !!1 Agree 100 %

Good evening Daselbee,

Thank you very much for the advice. I got the carb off and all cleaned up, was not difficult at all...I was worried about a spring or two flying off as I was disassembling but no difficulties at all.

After I replaced the carb onto the engine it fired right up!!! I went for a spin across the lake and I was very happy that it was running great! I stopped to cast the line for a few minutes to let it idle to see if I did indeed get it figured out.

Well...after that little trip across the lake I increased the throttle again BUT...this time I had no top end to it!!! I had full range of throttle 5 minutes earlier, now I have to 3/4 to full as it wants to stall. It sounds as though it is starving for something...doesn't stall but no torque.

The air needle valve was set at 1 1/4 turns so I played with it ranging from 1/2 turn to 2 1/2 turns but the engine never did get back to a full throttle operation.

I suspect that there is a piece of dirt inside that I never got out and it lodged itself in there somewhere. In any event I think I will take the carb off and give it a good cleaning again. This time I will use a small can of compressed air to blow out channels, I did not have a can of air when I first took it apart.

What are your thoughts? Am I on the right track?

Bruce

Well, yes and no.

The needle adjustment does NOTHING for high speed operation. It is an adjustment that fine tunes the fuel/air mix for idle only.

The lack of high speed could be caused by a bit of dirt that dislodged from inside the fuel line feeding the carb.

That piece of dirt would have lodged in the needle/seat area, restricting incoming fuel flow into the bowl.

When you do the re-cleaning again, LOOK for the problem. Examine the carb pieces for that elusive piece of crap that might be causing the problem. Do it like you were doing an autopsy. FIND the culprit.

Thanks Daselbee,

I am certain that is it a piece of dirt...the first trip across lake was great! I will don my medical gown and out my head light on and dive in, head first! lol

I will be sure to post the outcome!

Have a great day! It is supposed to go up to 30 degrees Celsius today so the evening should be perfect for a ride.

Well...I disassembled the carburetor...again. I used almost an entire can on it after giving each piece a through inspection (or so I thought). I reassembled carburetor and installed back onto motor.

It fired right up and idled great...I let it get to a warm operating temperature before I opened the throttle. Once again, as soon as I got to the top 3/4 throttle...bogged out and sounded like it was going to stall.

Could it be a coil issue? I will redo the carb again tomorrow, but not sure what I can expect of it now???

Is carb gasket 034512 installed around the high speed nozzle ??

What did you do with the fuel pump, filter, screen, supply line and tank? The dirt came from somewhere, brother..........you have a restriction upstream. The carb job is probably fine, I'm sure you set the float level properly.......right?

PS......This isn't rocket science.......but sometimes its close! You can't just fix the problem, you have to fix what caused it........

Good afternoon Timguy,
Well, I took your advice and went back to the basics...Airway, Breathing, Circulation and traced back and disconnected fuel lines from tank to pump and inspected the fuel pump/screen. Nothing blatantly obvious however.

It is reassembled so I may take a ride out to the late later today to try it again, I will bring an alternate fuel hose to rule that out if the problem still exists.

Adjusted float? This is new to me, I inspected the float and other than the little metal flap on the side of it I do not see how it can be adjusted other than to bend this tab?

Thanks Timguy...your advice and patience are appreciated! lol

Yeah these are pretty fool proof carbs. You can expect that maybe there is/was a restriction in the main jet passage. That would have had to originate in the float area or it would have had to pass through the needle valve for the float. Another in-line filter can help when installed somewhere between the fuel inlet fitting on the motor.....and the carb. It can be on either side of the fuel pump. Whenever the female fitting on the supply line is uncoupled at the motor, it becomes fair game for a little piece of crap to infect your fuel system. This will most certainly get to your main jet if it can navigate past the other safeguards. Deposits created by spoiled fuel......namely ethanol, will "shrink" jet openings. Even though air will blow through, you still have to physically clean the orfice bringing it back to its correct size. Never outboards are engineered to run as lean as possible, so jet openings are very precise.

Good afternoon Team Marine Engine....I am back! Here is the update.

1. The carburetor has been thoroughly cleaned,
2. Float set appropriately,
3. new fuel pump kit installed,
4. engine still dies out when it gets to 3/4 throttle.

During a recent rainfall there was a fair bit of water in the boat so I set out on the lake to run the boat and take out the plug to start draining. Initially I was unable to go more than 1/2 throttle without the engine bogging down, exactly what it does when compared to the 3/4 throttle...???!!! Once the water was out, I was able to go up to 3/4 throttle again, but nothing more??

Coils are working properly...

Any suggestions on what I should be doing next??

Thanks in advance for the help!

B.

What is happening is once the boat is under load, it reacts in this manner. The heavier the load, the less throttle I am able to apply. When it is test with no load (garden hose with attachments) I get a full throttle capability.

????----That is no surprise , that motor will rev up on one cylinder running on a hose.-That test is meaningless !-----What are the results of a compression test ?---Have you checked reed valves ?--Have you checked for a sheared flywheel key ?---Does spark jump a gap of 3/8" or more , yes or no ?---Have you checked to see if it is overheating ?----All too often carburetor / fuel problems turn out to be something else.

Are you reusing the old gaskets as they could cause air leaks, always use a OEM kit when repairing