1983 Suzuki DT-60 Outboard Not Running Well

[Fat Rap]

We have an 83 DT-60 outboard that has been running great for a long time but just last season started having some problems.

We've always taken good care of it and had it serviced when needed. It has only been in freshwater.

It isn't idling well, and often dies when putting it into gear.

Can someone offer some suggestions on where I should start diagnosing?

I do a lot of automotive work but haven't worked on a lot of outboards.

A few years ago we had the carbs cleaned by a local shop and it has been fine ever since.

Just to be sure, though, we ran a strong dose of Sea Foam through it but that didn't change anything.

It'll cruise along at higher rpms if you can get it into gear before it quits, so I don't think it's the fuel filter.

Thanks in advance for any advice or suggestions.

 

[Sea Rider]

Seems the idle rpm is too low, turn the carb's vertical screw some CC degrees more to raise the rpm, check if still dies.

Happy Boating​

 

[99yam40]

I would check compression, spark, and timing to make sure it is still in spec.

something has changed that should not have without someone moving things.
or an idle circuit in carb has plugged up
or a vacuum leak somewhere.

 

[Fat Rap]

Sea Rider: good point, I have not checked idle rpm. Judging by my ear, though, the idle seems normal. You're right, though, I should verify the idle rpm with the book setting.

99yam40: good thoughts on checking the basics. I also wondered if the timing somehow changed.

 

[Sea Rider]

Plan adjusting the idle rpm by ear or with a tach ? Once correctly adjusted to factory specs and if keeps dying probably the carb's idle circuit is somewhat clogged ? An internal carb clean will do good. Seen many motors with too low idle rpm dying when geared forward. Motor vibrations over time tends to loosen the idle screw CCW decreasing the ideal idle rpm it was adjusted to.

Happy Boating​

 

[Fat Rap]

Sea Rider, that's a great point about vibration causing the idle screw to loosen. I'll definitely add that to my checklist.

 

[ct1762@gmail.com]

carbs get dirty with this ethanol even after a couple seasons if its not been run much. sounds like idle circuit needs a look at. only takes 25 min to open carbs up!