Johnson two stroke twins

[Colin K]

Hello,
We have our old 1980's johnson at home to do the servicing and by Joe there was a lot to do perrished fuel pipes holes in carb bowls but all rebuilt. She will not start and I am on my forth rest break after pulling her over
She has just started to kick now and again in a sort of backfiring leave me alone sulky sort of way and I wondered if it is possible to wire the coils the wrong way around ? Years ago I put a set of spark plug leads on wrong on a car and it sounded simular. Manual is on board and cannot find any clues on line however 20 mins pulling over the dammed thing has numbed me :ambivalence:

Thanks for any help. Cheers. Colin.

 

[neil_s]

I would suggest that, since you've done lots of work on the fuel system, the carb is the place to look first. A quick check to see if you're getting a good spark would be easily done, though.

 

[oldharry]

20 minutes? You must be in training for a Strongman award! Seriously though, 20 minutes will have flooded the whole shooting match if fuel is getting through at all. Pull the plugs and see what state they are in. They should be stinking of fuel. Leave them out and pull the engine over again about a dozen times to clear the crankcase of fuel. If the there is no fuel, then thats your problem. IIRC each cylinder has its own breaker and coil? Its unlikely both have packed up. It shouldnt be possible to reverse them anyway, unless you have had the HT leads off altogether as they are (Should be) different lengths.

Other things to check particularly if there is fuel starvation is the pilot jet, and the air drillings in the carb, as well as the nore obvious main jet. Only takes one tiny bit of muck in the mixture conrol to make itimpossible t start.

Small 2 strokes are very fussy about fueling, and its very likely there is still a carb problem, particualrly if the carb was a mess. The old small Johnson twins are no exception.

 

[VicS]

Hello,
We have our old 1980's johnson at home to do the servicing and by Joe there was a lot to do perrished fuel pipes holes in carb bowls but all rebuilt. She will not start and I am on my forth rest break after pulling her over
She has just started to kick now and again in a sort of backfiring leave me alone sulky sort of way and I wondered if it is possible to wire the coils the wrong way around ? Years ago I put a set of spark plug leads on wrong on a car and it sounded simular. Manual is on board and cannot find any clues on line however 20 mins pulling over the dammed thing has numbed me :ambivalence:

Thanks for any help. Cheers. Colin.

What model precisely? ( hp and year, preferably model number)
Cdi or coil and points ?
What do you mean by "wire the coils the wrong way round" ?

It is possible to fit the coils of my '84 6 hp Evinrude " the wrong way round" but I am not sure what effect it would have. I marked them so that they go back in the original positions always because I do not normally disconnect the wiring from them.


Have you checked the compression?

Can you get sparks from the plug leads that will jump best part of a cm in free air ?

I assume you have confirmed that the float chamber is filled OK by the bulb

Perhaps you have flooded it, as OH suggests, but OTOH have you tried a squirt of 2t mixture directly into the carb throat

 

[VicS]

20 minutes? You must be in training for a Strongman award! Seriously though, 20 minutes will have flooded the whole shooting match if fuel is getting through at all. Pull the plugs and see what state they are in. They should be stinking of fuel. Leave them out and pull the engine over again about a dozen times to clear the crankcase of fuel. If the there is no fuel, then thats your problem. IIRC each cylinder has its own breaker and coil? Its unlikely both have packed up. It shouldnt be possible to reverse them anyway, unless you have had the HT leads off altogether as they are (Should be) different lengths.

Other things to check particularly if there is fuel starvation is the pilot jet, and the air drillings in the carb, as well as the nore obvious main jet. Only takes one tiny bit of muck in the mixture conrol to make itimpossible t start.

Small 2 strokes are very fussy about fueling, and its very likely there is still a carb problem, particualrly if the carb was a mess. The old small Johnson twins are no exception.

Depends on the HPand age. Most will be CDI by the 1980's

 

[Colin K]

Hello,
We have our old 1980's johnson at home to do the servicing and by Joe there was a lot to do perrished fuel pipes holes in carb bowls but all rebuilt. She will not start and I am on my forth rest break after pulling her over
She has just started to kick now and again in a sort of backfiring leave me alone sulky sort of way and I wondered if it is possible to wire the coils the wrong way around ? Years ago I put a set of spark plug leads on wrong on a car and it sounded simular. Manual is on board and cannot find any clues on line however 20 mins pulling over the dammed thing has numbed me :ambivalence:

Thanks for any help. Cheers. Colin.

Hello Chaps,
Thanks for the pointers. Checked for a spark and yes good, Swapped the coils around and hey presto she has fired up. Time to mark them top and bottom. Not ticking over too well but the fine tuning can wait until I regain easy movement of my right arm . Whilst checking for fuel delivery I found that the fuel pump rubber seal under the filter is in really poor nick so that could be the ticking over problem?

Once again thanks all. Col.

 

[VicS]

Hello Chaps,
Thanks for the pointers. Checked for a spark and yes good, Swapped the coils around and hey presto she has fired up. Time to mark them top and bottom. Not ticking over too well but the fine tuning can wait until I regain easy movement of my right arm . Whilst checking for fuel delivery I found that the fuel pump rubber seal under the filter is in really poor nick so that could be the ticking over problem?

Once again thanks all. Col.

I assume if you have remote tank?
If so check the fuel line for possible air in-leakage esp at the connector IF you renew the connector it is best to use a genuine OEM replacement as some after market ones are not so good and some other make s seem to fit but don't quite

Carb adjustment procedure here:

https://forums.iboats.com/forum/eng...nts-for-asorted-carb-variations-by-joe-reeves