Question about Boating

1 Answer

1970 johnson 4hp starts Very hard en works only two seconds

Cleaned the carb, has spark on both sparkplugs. After pulling several times it works sometimes but only two seconds.

Posted by on

  • Evert winter May 14, 2013

    Today again cleaned the carb. Now I got it running but not stable. Not at high speed and very variable speed. Could that be because of the fuelpump?



1 Answer

  • Level 1:

    An expert who has achieved level 1.


    An expert who has answered 20 questions.


    An expert that hasĀ over 10 points.


    An expert whose answer gotĀ voted for 2 times.

  • Contributor
  • 45 Answers

Not getting fuel, how old is your hose?

Posted on Jun 15, 2013


6 Suggested Answers

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

a 6ya expert can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of.(from cars to computers, handyman, and even drones)
click here to download the app (for users in the US for now) and get all the help you need.

Posted on Jan 02, 2017

  • 1 Answer


If you have a primer bulb and the motor "recovers" after a near stall with a pump of the bulb, then you have to replace your fuel pump. Johnsons do have this problem often. Otherwise it could be the high speed jets although it sounds like you checked the carb good. Also if you have a primer bulb, Replace everything from the tank to the engine. Costs about $14 at Wal Mart, $55 at a boat place.

Posted on Jul 07, 2009

  • 5537 Answers

SOURCE: Mercury 4hp had a spark when I used starting

The magneto or pickup coil could have been affected by the spray. When the motor turns the pickup coil reads the flywheel and produces the electricity for the coil. You may have rust on that part and the magnet in the pickup could be covered with oily rust. Test electric components and sand rust off.

Posted on Jul 09, 2009

  • 1810 Answers

SOURCE: 1975 75 horse johnson stinger wont idle in gear or run in gear

sounds like the reverse sensor switch is stuck in lock mode
check the switch

Posted on Aug 03, 2009

  • 86 Answers

SOURCE: I have an older mercury 4hp 2 cyl. Wont run. got

Ok, if you have fuel coming out of the throat of the carb then you need to readjust the float level. On that engine the best way to set the float level is to remove the carb. Remove the fuel bowl. Turn the carb upside down so the float is on top of the carb. You want to bend the tang (the piece that seats the inlet needle) so that if you are looking at the float it sits perfectly level. Once you reinstall the bowl and carb be sure to adjust your idle mixture and try it again. If it still spews out of the carb throat then take it back apart and do it again. If the inlet needle point is worn at all then you need to replace it so that it seats good. But if you set the float it is level when the carb is upside down you should not have a problem. You can put your faith in the fact that every spring I rebuild about 5 outboard carbs a day from people letting fuel sit during the winter.

Posted on Aug 07, 2009

  • 2 Answers

SOURCE: 30 hp johnson outboard motor trys to start. It

1985 30 hp johnson used a cdi system(solid state, no points) check the power pack.

Posted on Mar 09, 2010

Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

How to start a 1979 30 hp evinrude

Hey Norman,
There are only three things required for a internal combustion engine to run.
I have one issue.. I DO NOT see a 30HP built in 1970 - 1983?? They are 35HP. The first 30HP I see was built in 1984.
1. A good timed spark (New spark plug) - The correct one. (CHAMPION QL77J4 - qty. 2)-1984 30Hp.
2. A proper fuel air ratio (with yours also the proper oil/gas mixture)
3. Good compression (for your engine - w/carb wide open 120psi)
A service manual will help you (

Grab a buddy to help you do these..:
1. Make sure your spark plug will fire. Hold the spark plug hex against the head and have your buddy pull the should fire a juicy blue spark,, BUT - a healthy orange spark will work. If there is no spark..(double/triple check this!!).. stop here until you get a spark!!
2. Have the carb cleaned and a competent professional (one this old can be fixed by a trained professional motorcycle mechanic -its the SAME SIMPLE type carb - I repair "carbed" outboard engines too!).
3. You can hold your finger in the spark plug hole TIGHLY and have your buddy pull the rope.. it should BLOW your finger off the hole.. if you are not sure - get a compression gauge - use the 1/2" depth threads, screw it in until the oring seats..put the throttle wide open - WITH THE SPARK PLUG REMOVED and AWAY FROM YOUR HANDS...pull the starter rope hard about 5-7 times!! It should pump up to about 115lbs.+ minimum!!
If these above items are correct.. you engine should/will run!!

Jun 12, 2017 | Boating

1 Answer

Johnson 4hp seahorse won't start got sparks and fuel in carb. But it will not fire up

Try a little shot of starter fluid in the airbox. Usually works to get it cranking if you have gas & spark

Nov 09, 2013 | Sport & Outdoor - Others

1 Answer

Johnson 4hp seahorse

Time to pull the carburetor and have it rebuilt. Gaskets and floats inside act up and either flood or starve the engine of fuel.

Nov 09, 2013 | Sport & Outdoor - Others

1 Answer

Hard to start half to crank 25 to30 times it is discouraging help

few things to check first i would check my compression with a compression guage most small engines wont start easily if it doesnt have atleast 100 psi anything less makes them very hard to start this will also identify if you have leaking valves stuck valves or piston ring problems ect. next check to see if you have a spark. sometimes the spark plug is the culprit but you can check to see if you have a spark sever ways one is to disconnect the spark plug wire and in sert a phillips screw driver in the clip that holds the tip of the sparkplug and hold the well insulated handle and hold the shaft of the screwdriver near the block or head of the engine and pull the starter you should see and or hear a healthy spark. another way is to get a timing light and a 12 volt battery to power the timing light and connect the battery negative to the block of the engine tested clip the sensor lead on the spark plug wire while its still connected to the spark plug and it should flash when you pull the starter rope. or you can get a spark tester a good one has a neon light in it and a ground clip hold the spark tester to the sparkplug wire and it should flash as you crank the engine. if you have compression and spark next check your carb. assuming it has fresh good gasoline with no water in the gas your carb may be gunked up, clogged with trash or stuck float. remove carb and dissasemble starting with the bowl make sure its clean in there and the float and float valve isnt sticking then get a torch tip cleaner and ron the fine cleaning wires in ever orifice you can find. pull the main jet clean the tiny holes in it and spray carb cleaner in the carb body and parts. if it has adjustable jets pull them and clean. use compressed air to clean it out also. do not pull the welch plugs just yet if you do you will have to get a repair kit and takes some skill and patience to replace. reassemble carb carefully make note of were all the parts and pieces come from and replaces them. before removing adjustable jets count how many turns it takes to screw them in and only lightly seat them so when you pull them out you may return them to were they were originally adjusted. there are tiny holes near the butterfly throttle plate in the throat of the carb make sure they are clean and clear. if it is really gunked up there is carb dip but do not soak longer than recommended on the can as it will dissolve brass and ruin your carb. if you still cannot get it to run or run right. you can buy a new carb on ebay recheck valves or just bring the darn thing to a professional. good luck!

Nov 15, 2012 | Coleman Powermate Proforce 2500 Generator

1 Answer

Johnson 4hp starts first pull runs 5 minutes dies will then only run with choke on

You may have left the fuel vent closed. If working, put a clear plastic fuel line between the fuel pump and the carb. Look for bubbles indicating an air leak between the tank and the carb.

On a rear occasion you can have some varnish flakes floating round the fuel bowl. But these tend to cause random problems than the "about 5 min" problems you are having.

Sep 23, 2012 | Seloc Johnson Outboards 2002-2007 Repair...

1 Answer

I have a poulan pro 42cc pp4218avhd and i tried to fix. wont start, i clean out carb & changed s-plug. still no start. im thinking no spark going to plug.whats the gap for the sparkplug and how to...

First of all, these two stroke machine's carburators are very delicate, did you change the dioframe that controlls your petrol in and out stages?normally that gets hard and do not open and close, so your intake and outlet is open or closed all the time due to the hardness of this dioframe. secondly to test the spark, (somebody must help) take out the sparkplug put in in the the plugwire, get hold of a screwdriver or if the wire is long enough touch the metal of the sparkplug agaist the carburator(it must be on the metal of the carb), hold the wire at the back and let somebody pull it (as if you want to start) if the spark is there it means the dioframe is damaged

Dec 11, 2010 | Garden

1 Answer

My 1970 honda 100 has got a problem. It starts only a few times everytime I put in a new spark plug (and even then it starts hard) then it seems to burn out the spark plag badly. What can I do to make the...

Does it still have the original sparkplug cap? If so, from it's age, the resistance
in the cap has increased past it's optimum performance. Replace the cap or
(if possible) pull the resistor out and run it direct from the coil only if it's a
points style ignition not a CDI.
The resistor cap was put on all engines back in those days so it wouldn't interfer
with radio and television transmission signals.
Now days with CDI (capassitor discharge ignition) they need resistance on
the wire or cap or both, to clean up the high voltage going to the spark
plug so it don't hurt the CDI. Running a old engine with points with no
resistance wont hurt a thing.

Oct 28, 2010 | 1970 Honda CB 100

1 Answer


If you have a spark, it's not your ignition or flywheel because they both work together to make the spark.
Give a starter fluid squirt into the sparkplug hole (instead of thru the carb), screw in the sparkplug and give it a try.
Check your muffler to see if it's stopped up. You can just remove it for the initial check when trying to start w/starter fluid.

Oct 07, 2017 | Poulan Garden

2 Answers

Despite changing the sparkplug and proper choking, etc. no start

The most likely culprit is a clogged carb - a very common problem indeed on Tecumseh motors. Pull the carb off, open it up, spray everything with cheap carb cleaner (especially the bottom "bolt" that hold the float cover making sure it sprays out of at least two sides as that "bolt" is also the jet), make sure everthing lines back up as you pulled it apart and now try to start it up again! Bet it works, I see it all the time on small engines left with small amounts of gas in the system. Good luck, and I hope that gets ya runnin!

Mar 12, 2009 | Troy Bilt, Tuffy, Rear - Tine Tiller, 4.0...

Not finding what you are looking for?
Boating Logo

Related Topics:

49 people viewed this question

Ask a Question

Usually answered in minutes!

Top Boating Experts


Level 3 Expert

693 Answers

ray gallant

Level 3 Expert

45374 Answers

Fabrice Wolters

Level 2 Expert

320 Answers

Are you a Boating Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides