Johnson 3.5 hp 2 stroke

[Billows]

Last year after lifting off the boat it jammed.I couldn't pull it past compression.I suspect water got into the cylinder from the exhaust as I may have raised the leg higher than the power head.I took out the sparkplug and it freed up and ran ok. Since then when I try to restart after a period of non use I get the same symptoms.I cannot pull it past compression until I remove the sparkplug and give a good few pulls.Then when freed up it runs fine, starts first pull.It emits a cloud of blue smoke when starting up after a period of non use too.Any idea why this is happening?Any remedies?

 

[VicS]

You don't give any model details ... approx age for example

Is it one of the ubiquitous re-badged Tohatsus.

Did you confirm that the trouble was due to water or is the blue smoke a clue to fuel leaking past the tap and flooding the engine

 

[No Regrets]

Leaky carb? (float valve?)

 

[Billows]

It is one of the rebadged Tohatsus. The blue smoke happens at startup only after a period on nonuse .Water is speculation as the first time it happened I had bundled it in over the side of an inflatable head first. Leaky float valve is definite possibility as I have had a few instances of fuel leaking from the carb, cured with a gentle tap by a hammer on the bowl.I have cleaned the jet and bowl with carb cleaner during which I had to reseat the float valve.I can halt the engine by closing the tap.It revs up just before cutting.

 

[VicS]

How is it stored during "non use". Still thinking along the lines of flooding with fuel. If vertical both fuel tap and needle valve would have to let by slightly. If not upright then float valve would not be effective any way so possibly the tap leaking very slightly.

Sounds as though the float may be sticking anyway or needle valve not seating properly

 

[Billows]

Stored upright so would have to be both.No possibility of corrosion in the cylinder,rings?As a test I guess I could empty fuel, run it dry and store to see if problem persists.

 

[macd]

Billows: you say that it freed up after removing the spark plug. Was any force required?

Revs rising just before engine dies after shutting off fuel is normal: the mix is leaning out as the fuel level in the float bowl drops. It also shows any fuel leakage is small, but not necessarily absent. Regardless of the condition of the float valve, the fuel tap should prevent leakage while stored. Have you checked the tap minutely?

If it's a mechanical seizure due to being dunked, it could be the main bearings. If so, the engine would be very rattly once freed off, which you'd probably have mentioned.

Why not whip the head off and check out the bores: simple job, just 4 x 6mm bolts.

 

[Billows]

Are these engines rebadged Suzuki or Tohatsu and where can I download service manual or at least parts exploded diagrams?

 

[VicS]

Are these engines rebadged Suzuki or Tohatsu and where can I download service manual or at least parts exploded diagrams?

A convenient site for exploded diagrams and parts lists is www.boats.net

Owners manual for recent Johnsons and evinrudes should be avaialble on line... darned if I can find them though. Older ones either from a dealer or for 1996 and earlier http://www.outboardbooks.com

Tohatsu parts also at http://tohatsuoutboardparts.com/

Johnson and Evinrude parts lists at also at http://epc.brp.com/SiteMods/BRP_Public/BRP_Public_Login.aspx?ReturnUrl=/Index.aspx

http://www.marineengine.com/parts/johnson-evinrude-parts.php also includes parts lists for pre 1968 Evinrudes and johnsons

 

[Billows]

Seizing problem after non use seems to have resolved itself.Probably flooding through carb.
I took the integral tank off and separated it from the tap to try to clean fuel filter.Something resembling a filter was pushed up into the tank outlet but was unable to remove it.Is this the filter or does the filter reside in the the tap?How do I clean it in situ if the former?The diagram on boats.net is not clear.