NS 9.9b cooling water check port

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I'm back at last. Just talked to the shop. They were not able to get the water check port open. They replaced the impeller after having a hell of a time getting the lower unit off due to corrosion at the bolt holes. It's running cool and water is coming out with the exhaust. They say not to put any more money into it and just run it until it croaks. Not what I wanted to hear. How much other salt damage could there be? I won't be taking it out on the Columbia. I mean, how would I know that it's about to croak and not get stuck out on the water someplace? That motor might be OK as a kicker, but I don't think I want to get very far from the launch.
 
Uncle Krusty said:
I'm back at last. Just talked to the shop. They were not able to get the water check port open. They replaced the impeller after having a hell of a time getting the lower unit off due to corrosion at the bolt holes. It's running cool and water is coming out with the exhaust. They say not to put any more money into it and just run it until it croaks. Not what I wanted to hear. How much other salt damage could there be? I won't be taking it out on the Columbia. I mean, how would I know that it's about to croak and not get stuck out on the water someplace? That motor might be OK as a kicker, but I don't think I want to get very far from the launch.
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Sad to hear ... I would remove the t-stat cover and FILL that port/tube going down to the exit with white vinegar or some other solvent to try and dissolve that built-up salt. You might also try some spring steel or wire down that tube chucked up in a hand drill and spun s-l-o-w-l-y to see if it removes anything. Cut a sharp angle on the end but dull the point, so only the sides of the straight cut cuts into anything, you don't want the 'tip' to pierce anything and start drilled a new hole.

I had never asked my local Nissan mechanic, but need to head there sometime in the next week or two. If I learn anything about that port and blockages, I'll report back.
 
Thank you Dale! That impeller was not cheap. I guess it took a long time to get the lower unit off. Glad I didn't try it myself. I'll have to figure out how to get the thermostat cover off. BTW, any choice words on repairing a pinhole leak?
 
Uncle Krusty said:
Thank you Dale! That impeller was not cheap. I guess it took a long time to get the lower unit off. Glad I didn't try it myself. I'll have to figure out how to get the thermostat cover off. BTW, any choice words on repairing a pinhole leak?
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If you dont mind me asking, what did they charge?



Also with a motor with calcium/salt build up like that, run it in a garbage can with lots of vinegar in the water.

Im talking 5-6gal of vinegar in a 30gal can with just enough water to cover the pump.


Run it for an hour or so and youll be amazed at what comes out.
 
I’ve never run one w/ all vinegar as coolant ... so while ‘wary’, I dunnoh. But I have filled the cooling passages in powerheads w/ vinegar & have left them sit for days and rinse/repeat and have had great luck w/ small OBs running cool or as designed, where they used to run ‘hot’.

If it were mine, I’d try the less drastic/invasive method of filling that port w/ vinegar & seeing what happens ... or would try a household ‘lime or descaler’ product before I’d run the motor in a tub of vinegar. Make sure to flush out the vinegar or descaler solution w/ water. HOT water might help dissolve the crud too! Your arms/back will get a work out from tipping that OB up & over, so be careful!!
 
DaleH said:
I’ve never run one w/ all vinegar as coolant ... so while ‘wary’, I dunnoh. But I have filled the cooling passages in powerheads w/ vinegar & have left them sit for days and rinse/repeat and have had great luck w/ small OBs running cool or as designed, where they used to run ‘hot’.

If it were mine, I’d try the less drastic/invasive method of filling that port w/ vinegar & seeing what happens ... or would try a household ‘lime or descaler’ product before I’d run the motor in a tub of vinegar. Make sure to flush out the vinegar or descaler solution w/ water. HOT water might help dissolve the crud too! Your arms/back will get a work out from tipping that OB up & over, so be careful!!
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:roll:

He'll be lucky to get a 20% solution in a 30gal can.
 
Life slowed down enough that I could at least fire up the motor. Water comes out of all the places it should, except the telltale. I ran it about 15 minutes and the powerhead was barely warm, so that all seems good. However. It idles rough as all heck, lumpy, lots of vibration and smokes a tad. I doubt this is a "oh, they all do that" kind of thing, so I'll be having a conversation with the shop in the morning. They said the compression was OK. The saga continues.
 
Uncle Krusty said:
It idles rough as all heck, lumpy, lots of vibration and smokes a tad.
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Sounds like it needs a tuning ... see the OEM Factory Service Manual attached. It is a 2005 dated Manual but still works for my 90s vintage OB 2-stroke.
 

Attachments

  • Tohatsu 2-Stroke 1&2 Cylinder OB Motors (2.5 to 40HP) Service Manual 2005.pdf
    38.6 MB · Views: 7
Once you get it running well enough to 'run it a while', I'd take a can of Seafoam, and enough gas to make a 1-gallon mix, but add 'extra' TC-W3 oil than just what's needed for the 1-gallon (go a little heavy on the oil amount) and mix well.

Then run it in the water or in a barrel (NOT on muffs!) at high idle for 10-minutes at a time, then shutoff for 15-mins. Repeat, repeat, repeat ... even over a few days, so this is where a large plastic barrel is handy. If in the water, you can put it in gear & throttle up/down some too. That should clean her out and decarb the motor at the same time.
 
So. Looking things over, I noticed that the fuel filter bowl had a lot of sediment and figured a carb rebuild would be in order. After calling around it seems there are no carb kits or individual parts available although the guy at boats.net spent a lot of time looking. But I figured I could at least clean it out, so I removed it, being veeerry careful with the gasket at the powerhead. It turns out that WD40 will loosen those. Then I hosed it down with carb cleaner, even though it was pretty clean. The fuel in the bowl was pretty murky. Reinstalled everything, again being very careful and slow, as I have a tendency to assemble things upside down and backwards. I also got a new fuel line and tank fitting because the old one was old and the bulb had some cracks. Hooked it all up, put on the muffs, held my breath and pulled the cord. Fired up on the second pull. I was amazed. And ran much smoother. It's still catches some and surges a bit, but much better. Next I'm going to check the compression and I'm wondering if the mix is a little rich, so I have to figure out how to deal with that. There is still a lot of smoke. Also going to get a tach and play with that. I have before and after video but don't know how to post it. Feeling better about that motor.
 
Good weather and spare time have collided and I'm off to the lake. To be sure, I started the motor first. It still runs smoky and the outflowing cooling water smells strongly of fuel and you can see it on the water on the ground. Seems like it's running rich. Anyone know how I adjust that? There is only one visible screw on the carb which I'm thinking is what to use but maybe it's something else.
 
Report from the lake. It ran "ok" and we took a couple of laps around the lake, WOT. On the third lap, it suddenly throttled up and went like heck. I was super pleased until it suddenly died. After that, it would only run, reluctantly, with a little choke. It was worthless enough that I used the MinnKota to get us to the launch. It now idles like a champ, much less smoke. It seems like it was starved for fuel at WOT. Is there a high speed jet in this carb, or some adjustment I can do from the outside?
 
Couldn't find adjustment instructions where you said, but I have a feeling that it's obstructed from within. If it ran great for a while and then started surging and dying, maybe some crud got in there, or t hey were dirty and stuck. When I cleaned the carb I was nervous about getting that deep into and didn't do those jets. I think I'm going to try that.

What's the verdict about testing the engine at higher RPMs when it's on the muffs?
 

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