Outboard slow-running problem

[MIKERICHES]

Can anyone suggest solution to a problem with my newly-acquired but VERY old 2hp Johnson two-stroke outboard, built 1983. Starts easily and runs well at medium and full throttle, but cuts out at anything below half speed, and certainly won’t tickover.
Took it to a well-respected local dealer who serviced it, changed the impeller and cleaned the carb (he found no dirt) and fuel tank, and “ultra-sound tested” the carb (whatever that means) but couldn’t cure the slow-running problem.
On YouTube there are several American videos of people using same engine, but I note that on all of them there are two knobs to adjust slow and high speed running, while on my engine there are similar apertures but adjusting screws instead of knobs. Is this normal to my model, or has someone made a modification that is the root of the problem?

Model number is: J2RCTD, and serial number is: B029172, and supplier: Outboard Marine Belgium NV, Brugge, Belgium.

 

[RichardS]

It's got to be a carburation problem but if it was simply adjustment of the idle jet or fuel float level then presumably the dealer would have sorted it.

Perhaps the idle jet has been replaced by one that is incorrect although I can't imagine why.

I would be inclined to strip down and clean the carb myself and play around with the float level if adjusting the idle jet (assuming it is adjustable) makes no difference.

Richard

 

[VicS]

Can anyone suggest solution to a problem with my newly-acquired but VERY old 2hp Johnson two-stroke outboard, built 1983. Starts easily and runs well at medium and full throttle, but cuts out at anything below half speed, and certainly won’t tickover.
Took it to a well-respected local dealer who serviced it, changed the impeller and cleaned the carb (he found no dirt) and fuel tank, and “ultra-sound tested” the carb (whatever that means) but couldn’t cure the slow-running problem.
On YouTube there are several American videos of people using same engine, but I note that on all of them there are two knobs to adjust slow and high speed running, while on my engine there are similar apertures but adjusting screws instead of knobs. Is this normal to my model, or has someone made a modification that is the root of the problem?

Model number is: J2RCTD, and serial number is: B029172, and supplier: Outboard Marine Belgium NV, Brugge, Belgium.

1983 is not VERY old for a Johnson. Not even old. In the USA people run Johnsons and Evinrudes that are a lot older.

Accoding to the parst list ( see http://epc.brp.com/Index.aspx?lang=E&s1=ccb909c0-ebd7-40d3-a60b-847fa67aa585 ) there should be knobs on both mixture adjustment needles .... but they pull off so probably been taken off / fallen off and lost. No worries you can adjust with a screw driver.
They are still available as parts if you really want to replace them ( but the grommet around the low speed knob is NLA)

Check that the screws are not loose. If they are the packing washers may need replacing or with luck just the retaining nut tightened a bit.

Assuming the carb has been properly cleaned see Joe Reeves' instructions for adjusting the mixture screws on the iBoats forums at
http://forums.iboats.com/forum/engi...nts-for-asorted-carb-variations-by-joe-reeves

You should find the motor covered by the manual at http://boatinfo.no/lib/evinrude/manuals/1971-1989johnsonevinrude.html

Sort it out, get in running well and you should get many more years of service from it.

Checked the compression, cleaned and reset the points, inspected the coil, fitted a new spark plug, Champion RJ6C, gapped at 0.030"


You have not filled in a location in your profile so dont know where you are but

Oakley Marine (aka Outboards-direct) in Brighton http://www.outboards-direct.co.uk/ and Wills Marine in Devon http://www.willsmarine.co.uk/ are good for spares

 

[VicS]

It's got to be a carburation problem but if it was simply adjustment of the idle jet or fuel float level then presumably the dealer would have sorted it.

Perhaps the idle jet has been replaced by one that is incorrect although I can't imagine why.

I would be inclined to strip down and clean the carb myself and play around with the float level if adjusting the idle jet (assuming it is adjustable) makes no difference.

Richard

Which part are you calling the "idle jet"

 

[RichardS]

Which part are you calling the "idle jet"

I don't know that engine but whichever jet is used to a vapourise fuel at idling speed. Usually a separate jet from the main jet but sometimes not. As long as it's adjustable it's worth trying to adjust it but surely the dealer would have been through that process?

Richard

 

[VicS]

I don't know that engine but whichever jet is used to a vapourise fuel at idling speed. Usually a separate jet from the main jet but sometimes not. As long as it's adjustable it's worth trying to adjust it but surely the dealer would have been through that process?

Richard

The two screws # 15 and #23 adjust the idle and high speed mixtures respectively.
#9 is the high speed nozzle.
The OP would do well to make sure the gasket #21 is in place.

 

[Spirit of Glenans]

Took it to a well-respected local dealer who serviced it, changed the impeller and cleaned the carb (he found no dirt) and fuel tank, and “ultra-sound tested” the carb (whatever that means) .

I think it's more likely he dismantled the carb and cleaned the parts in an ultrasonic bath, which causes a very frequency vibration to dislodge any dirt.

 

[MIKERICHES]

THANKS to all those who replied to my plea for help over Johnson 2hp that won't run slowly. Brilliant response giving me plenty of food for thought. Consensus is that it MUST be the carb, even though dealer had it off and cleaned it. Will now strip it myself to see if he missed something.

 

[Heckler]

THANKS to all those who replied to my plea for help over Johnson 2hp that won't run slowly. Brilliant response giving me plenty of food for thought. Consensus is that it MUST be the carb, even though dealer had it off and cleaned it. Will now strip it myself to see if he missed something.

Somewhere in there is the slow speed jet, sometimes they are removeable and sometimes cast in. I get a bristle out of a wire brush and poke it thru and wriggle it. It gets rid of varnish which the ultra sound doesnt. The purists say never use metal to clean jets, I have been doing it for 50 odd years and have never had an issue!
S