2016 suzuki df20a manual start tiller exhaust problems

[mtnbowhunter]

I am wintering in baja, mexico and having an exhaust issue with my df20a and REALLY NEED HELP HERE!!
df20a with approx. 200 hrs on it with 2/3 of that in salt water

after storing the engine for 2 months I started it here and immediately had a lot of exhaust / noise coming thru the upper dry ex port, sounds at times depending on rpms, like an old lawn mower with a bad muffler!.
no ex. goes thru the hub until just before the neutral rev limiter kicks in, lots of water coming thru the pisor water vent at the upper ex.,
but the upper exhaust has very little if any water in coming out of it.
if I plug the upper ex. with my finger it starts coming thru the hub and it is quite hot
at speed when moving there is still a lot of ex. /noise coming thru the upper ex.!
at approx. 1/4 to 1/3 throttle when fast trolling the upper ex. is very loud and if u back offr the throttle quick there is a slight ex. crackle like in our old hot rods1
engine running fine with no warning/problems lights coming on and I have used it like this for about 8 hrs at all speeds
What I have done so far: ( I have the shop manual, but it does NOT have good diagrams of ACTUAL ex. passages, only a water flow chart)
- removed prop and lower unit, l;ooked for blockages and checked the impellar, all looked great
-removed the thermostat and checked it as per the manual and all okay.
-visually checked what I can easily find for ex. passages and no sign of blockages
- the water supply hose that goes from the leg to the fuel cooling block was split right at where it joins onto the leg to suppl;y the water,which was a surprise, but I repaired that
-there is NO water showing up in the engine or gear oil

on an idea note. the engine was stored on my inflatable OUT OF THE WATER, with the engine angle at an little above the fully down position, or the first click/lock when tilting the engine up and was exposed to some VERY minor, SHORT period, SLIGHTLY below freezing temps, but that has never been an issue before
-there is a possibility that wasps or spiders could have crawled up the upper ex port and made a nest, but I never noticed that happening and u would think that should have blown out by now/

so, the obvious questions are:
-what do u think is the issue here? and of course, how to fix it?
-what normally makes the ex. go thru the hub instead of the upper ex. port? is there a valve,etc. somewhere

I really need your help here gang as I am a long way from a Suzuki marine dealer
I do not have internet ev ery day so it may take me 2 days or so to respond.
HELP!!!

[pmaru77]

***.....no help? I'd start with inspecting your water pump. water and exhaust are combined........when my pump went, I got similar results.

[mtnbowhunter]

as I mentioned above the impellar / pump is as new , all water passages appear clear and u can easily blow air from the water tube going from the pump up to the motor/thermostat
if I restrict the upper exhaust port from 1/2 in. down to 3/16 in. everything works as it should, exhaust going thru the hub at lower rpms and no noise from the upper ex. port!!!!??????????
no warning lights from the engine and running fine

[Solarman]

It seems many problems related to poor exhaust, weak tell-tales, delayed streams, and similar problems, occur when tell-tale tubes are blocked (stiff monofilament usually clears this), or the water pressure valve/and/or thermostats are dirty (stuck open/not closing/[reducing back-pressure] and need cleaning or replacing). Sometimes a good corrosion flushing would clean up many of these problems. But these signs do indicate possible future problems. I would try a vinegar flush, in a barrel/tank container, running the motor for a good 1-2 hours total time (letting same solution cool for a couple hours between running times), and keep solution above water pump at all times during running.

Good luck, post back when able to let us know what you find out.


Good luck.