Thread subject: Whaler Central - Boston Whaler Boat Information and Photos :: 1976 40HP Johnson Stops Running

Posted by rcj on 07/04/12 - 5:21 AM
#1

1976 Johnson (40HP) on 1976 Sport 13 ususllay runs very well but occasionally stops--The "stop" is not immedate (engine slows down and then stops) so I don't think the problem is electrical. When re-starting sometimes it is necessary to disconnect the fuel line and after a few spins the motor starts. Seems as if the engine was flooded. Some days this never occurs and other days it may happen 2 or 3 times. Could use of gas that contains ethanol with a motor that is 36 years old be a contributing factor?
All input appreciated.
Happy 4th of July to all!
Thanks
RCJ
Lafayette, LA

Posted by brorobin on 07/04/12 - 6:13 AM
#2

Possible problems:
- Fuel lines beginning to deteriorate and break down internally
- Check your tank vent. The vent screw on an old tank I had would "open" but had gunk underneath that essentially keep it closed.

These are some issues that I have faced. Check the simple obvious things first. An old saying goes: "If you hear the sound of hoof beats outside, you should look for horses and not zebras"

Posted by rcj on 07/04/12 - 7:11 AM
#3

Thankjs Robin,
Both suggestions appreciated very much. I will change fuel line (the present line is showing it's age externally) and inspect vent today.

Best Regards,
Dick Johnson
Lafayette, LA

Posted by CES on 07/04/12 - 7:33 AM
#4

Older fuel lines are definitely affected by ethanol in our modern fuel. Like was mentioned above, I'd change out the fuel lines and filter.

Additionally, I'd take the carbs apart and thoroughly clean them. Sounds like you might have a dirty carb too.

Good luck and post up your results if you resolve your issue.

Posted by contender250 on 07/04/12 - 8:00 AM
#5

This is a carb problem, but the ethanol does not help either, The carbs on the older outboards have a set screw that sometimes gets flat at the end do to over tighten, get a new carb kit and got through it, try Boats.net for old parts. Also as stated above I would clean out the gas lines and pump (sometimes the ethanol will collapses the gas line from the insides, may need to change the line). These are very good engines and easy to fix. take care

Posted by rcj on 08/04/12 - 2:20 PM
#6

Thanks for all the suggestions--Yesterday I picked up a new fuel line and also changed the fuel line tank connector as well as the fuel line engine connection. Cleaned out both tank caps and they did have some gunk in both.
Ran 2 tanks of fuel today with no problens. Got gutsy enough to even veisit a couple of remote swamp areas.
Thanks to all for your suggestions and help. It worked!
Best Regards,
Dick Johnson
Lafayette, LA