Suzuki DT 140 runs good for awhile

[kksalm]

I have a new to me 1986 DT 140 outboard that runs great for about an hour and then shuts down and won't start. It runs a little rough around mid RPM's but once you get past that it runs great. I have various fuel tanks and different hoses I've switched over so I don't think it's connected to contaminated fuel. Any suggestions will be much appreciated.
Thank you and best regards, kksalm aka Kenai King Salmon

 

[JUSTINTIME]

Re: Suzuki DT 140 runs good for awhile

well you need to test fuel pressure and vacuum
might need carbs rebuilt

 

[kksalm]

Re: Suzuki DT 140 runs good for awhile

Why would it run so good and then quit? Wouldn't something wrong with the carbs be present always?
Thank you for the reply.
Best regards, kksalm

 

[tryhard]

Re: Suzuki DT 140 runs good for awhile

kksalm,

sounds just like what my DT85 is doing.

I cant help you 'cause I do not know enough about these things.

If you read my post 'DT85 stalling & difficult to start' you might get some info from there.

As for me, well, I am resigned to taking it to the mechanic.

good luck - the guys here certainly have some sound knowledge.

 

[JUSTINTIME]

Re: Suzuki DT 140 runs good for awhile

might be related to heat also

 

[rodbolt]

Re: Suzuki DT 140 runs good for awhile

the only way to find it is to isolate the problem while its occuring.
its either fuel or ign, the easiest to check when it quits is spark.
you can either spark test it, use a Kv tester or monitor ign coil primary voltage.

 

[bexi]

Re: Suzuki DT 140 runs good for awhile

hi,
i'm not a boat mechanic but i did my trade as a motorbike mechanic so know the basics.
i really really don't think it's anything to do with fuel as it wouldn't run so well and then not at all. it definitely sounds like an electrical problem.
one thing that i've come accross a fair bit on motorbikes with similar symptons is faulty coils. often a bike would stall and if you leave it for an hour or so it'd start up again and run great.
is this similar to yours?

 

[rodbolt]

Re: Suzuki DT 140 runs good for awhile

simply test it, its quicker and easier than guesing and way cheaper.
myself I would carefully look at the stop circuit, stator and CDI.
its all easy, only take a peak reading multimeter or a DVM with a DVA adapter.
just remember its a simple ADI ign system.
keep in mind the difference between spark producing components and spark controling components.

 

[JUSTINTIME]

Re: Suzuki DT 140 runs good for awhile

do the test as rodbolt stats cold
then use a heat gun and warm things up

 

[kksalm]

Re: Suzuki DT 140 runs good for awhile

Thank you all for the leads. I'll get to work on it this week. I need to either back it in at the boat ramp or locate a big barrel of water. Or else bite the bullet and buy that kicker I'm needing for this boat and wait for a weather break and head on out. I'm in Dutch Harbor, Alaska, and there's plenty of places to avoid having your motor quit.
Best regards, kksalm