'95 150 shut down???

[Stevie-b]

Glad I found this board. Great feedback. However, I checked around and didn't see anything matching what happened to me last weekend. Running a '95 150 SW on my bayboat for past 4 years and has been great. Headed out just at day break and run up on a crab trap. Couldn't turn, so shut it down... from say 4k rpms to idle. Afterwards engine will not idle w/o choking and/or quickly hitting gas after start. Also could not get up past 2800 rpms for 20 minutes back to ramp. Messed w/ cleaning carbs, then ran engine under load on trailer and pulled plugs one at a time to check firing. Only 3 of 6 cylinders appear to be firing. Reved engine higher under load, checked again, and seemed all 6 were firing. Launched boat and ran perfect for rest of day. Guy at marina suggested I tripped a temp. sensor when shut it down so fast. I have however done this before w/o any issues. Any ideas? And if it is a sensor issue is there some sort of reset?

Thanks,
Steve

[Ken]

Steve,
Yea Austin! Yea Longhorns! Yea University of Texas! (ok, I had to do that - I graduated from there many years ago [img]smile.gif[/img] ).

Now, regarding your post - those pesky !@#$% crab traps - got a million of them over here in Sabine Lake with no floats, thanks to Rita, all now are ghost traps just waiting to be hit.
I really can't corrolate your running into the trap with the symptoms you describe, except maybe the jarring of the motor may have loosened the connection of the shift and throttle cables - check them and also the idle stop screw. Your idle rpm should be around 700.
You have two "temp sensor" or thermo switches mounted in the heads of that V-6, one in each head, of course. They are nothing more than bi-metallic strips housed in a little round can with a set of contacts on one end. When the temp of the switch gets up to around 180 degrees f., the contacts close and send an overheat signal to the CDI. The alarm instantly sounds and a few seconds later the motor goes into rpm reduction mode - shakes violently because the CDI has cut back on the spark and is telling you to throttle back to idle until the overheat condition is corrected. The thermo switches re-open at around 160 degrees.
There is no "reset" for the switches.
What symptoms do you have now? Motor running ok?
I would check that prop shaft to make sure it is not bent a little.
Good luck [img]smile.gif[/img] ,
Ken K

[jb123]

engine will not idle w/o choking and/or quickly hitting gas after start...definately a fuel issue, check separator,filters and carbs. no buzzer goin off?? ,might wanna check into that also.

[Stevie-b]

Ken thanks for the response. I appreciate your enthusiam... I had a big crowd over to watch a great **** and was pulling for the Horns... I'm actually an Aggie though, but a Texan first. To make a clarification. I didn't actually hit the trap, but ran over the float and tore it up a little (probably in 8 ft of water). Prop, shaft and everything else were fine. Basically motor just would not run right for a while, but later ran fine.... quick shut down seemed to create the issue, but no buzzer. 3 of the 6 cylinders weren't firing when first checked them under load (about an hour later), but roughly 15 minutes after that motor started running fine w/ nothing else done other than sitting for about an hour. Oh yea, I did add 15 gallons of premuim to a 50 gallon tank w/ fairly new gas, before I put it back in.

[Ken]

Steve,
Nothing wrong with being an Aggie - heck, my dad is one [img]smile.gif[/img] !
Reading back over your posts and what comes to mind is maybe water in the fuel tank - would be consistent with the symptoms you had. Do you have a filter/water separator in addition to the local filter? Might want to add one. Racor makes a good one - has a see-thru bowl so that you can look and see water collected in the bottom.
With a fifty gallon tank, say only half full, condensation could easily form during the winter and collect at the bottom. Maybe when you did the emergency shutdown, that water got sucked up into the fuel pickup tube. You might want to add a fuel stabiizer like Sta-bil or SeaFoam to the tank - both are suppose to absorb small amounts of water in the fuel.
Good luck [img]smile.gif[/img] ,
Ken K

[boats.net]

It does sound like like a fuel problem, those OH S___ stops tend to jar stuff loose in carbs, fuel filters and such. Also on some boats the backwash of water will swamp engine fill air silencer full of water and wet elect. connectors and it's just a matter of drying out. If you think motor got swamped then you might unplug some of the wire harness connector's and check for water, spray them with silicone to dry water out.

[Stevie-b]

We'll, I did have Stabil in there and actually bought some Seafoam after reading posts yesterday. I'll try it all. Thanks guys!

[bernieb]

I have read on another board that stopping that quick can cause water intrusion through exhaust if engine sets low in the water.