1991 Four Winns 170 Freedom 3.0HO GM Straight 4 with Cobra Stern I/O

[bruceb58]

Some of the symptoms and description sound like the carb may be leaking raw fuel into the intake and flooding it somewhat. When it becomes hard to start move the throttel to near wide open (in throttle only mode!) and crank it, be ready to move the throttle back when it catches. If this procedure works then the carb may be draining into the intake and thus engine is flooding in between uses and the carb may need to be rebuilt.

Yes, I agree with that too. I am also wondering if the fuel pump has failed and is sending fuel up the clear tube to the carb,

 

[MikDee]

Oh yeah its cranking fine. I had the battery tested its only about a year old and tested perfect. I sanded down all the terminals/connections they weren't terrible. This is why I believe its a spark issue because the motor cranks fine and sounds like it wants to start but doesn't. I just am not sold on it being the wrong plugs because the engine ran fine several times with those plugs, but its a starting point.

Those are the wrong plugs, they're probably sticking into the combustion chamber 3/8"! The right plugs would be flush with the inside surface of the combustion chamber! That's the way it's supposed to be. When you take them out, they might have some carbon buildup on the lower threads that are inside the combustion chamber.

 

[ConnieMarie]

Three of the four plugs did have carbon build up when I swapped them out. I've tried having a helper hold top of carb wide open while I turned key to start and nothing. When I stop gas continues to come out of straw sized tube and drip down into carb. Also how would I do throttle only mode? I can't get throttle to move without pressing gear button.

 

[MikDee]

There should be a button on your control box that when you push it, you'll be able to get throttle only, it disengages shifting for starting, and running

 

[bruceb58]

If you are not giving it any throttle when you are starting, that's going to be a huge issue.

Take a picture and post of the tube that the carb is dripping out of.

 

[ConnieMarie]

Picked up new plugs today. I haven't given it any throttle when starting it never needed it before, but ill try that. I'll get pictures Friday when I can get to the boat. I really appreciate all your help guys, very informative!

 

[ConnieMarie]

For the record, according to NGK website, they claim the TR5 is the correct plug for the 3.0 HO engine. This is how the previous owner decided to go with that particular plug.

 

[bruceb58]

I don't think you have a H.O. engine. What makes you think that?

 

[ConnieMarie]

The plastic shield on top of the carb has a sticker that says "3.0 HO litre"

 

[bruceb58]

That's interesting!

From the BRP website(took over OMC) and using your model number 302CPRPWS you see the recommended spark plugs:

Here is the cross reference from champion to NGK:
http://www.sparkplug-crossreference.com/convert/CHAMP_PN/RV12YC

 

[bruceb58]

So much conflicting info. I am now thinking your plugs were correct!

The deciding factor of course would be to measure the depth of the threads in the head.

Very confusing for sure.

 

[ConnieMarie]

Thats why i am not sold on the plugs because I had the NGK TR5 and it ran fine for weeks. I would also think if the carb was shot I could still get the engine to start.

 

[ConnieMarie]

Thats why i am not sold on the plugs because I had the NGK TR5 and it ran fine for weeks. I would also think if the carb was shot I could still get the engine to start.

 

[Maclin]

Hard to work with a finnicky carb if you do not use throttle-only mode, almost impossible to clear a slightly rich condition if you cannot move the throttle to wide open while cranking. I think you mentioned at one point the plugs looked wet, if the carb is letting raw fuel into the intake manifold then the plugs can wet-foul, and in that condition they can just not allow spark to jump the gap. Have to remove them and let them dry out for a bit, rough the tips up some, reinstall and crank again with throttle open. If flooding is the issue then you will not be able to avoid carb work.

 

[ConnieMarie]

Alright, So I went to troubleshoot Friday and with my multimeter started pulling things apart and testing. Below is an image of the carb and the area where I can see gas drip out after trying to start the engine. It drips down the center to the bottom, but stops a few seconds after unsuccessfully starting. I dont believe the carb is the issue I will explain...

So as I'm pulling things apart I started with the battery which had a great reading. Next was the starter motor which had full power running to it. The solenoid had a great reading going to the main distributor wire (red arrow). Had full power at the purple and grey wires going to distributor. I am not sure how to test if power is running through the main distributor wire from solenoid to distributor.

Next, I had a faint reading on the grey/white and grey/black wires(yellow circle) but only got the reading and it faided out could not get it again. I unplug (green #1) to try and test and I really am not sure how to get a reading through any of the wires from solenoid. I tried positive inside and ground my meter but nothing. I did originally have four new cylinder wires, but not main distributor wire from solenoid connected, I put old ones back on after thinking maybe new ones were the issue. So at this point I plug everything back together. The boat fires up effortlessly and runs extremely smooth several times as if nothing was ever wrong. So I did not have time to go for a ride that day. Went Sunday tried to start, WOT this time, and it started but as I eased the throttle engine stopped and would not start again. I tinkered with wires on the top of distributor a couples times and twice it started, but again eased off throttle and engine stopped. After this, the engine would not start at all and im back to square one. For some reason, I believe the main distributor wire or distributor is the issue. I have not taken the distributor cap off at this point, it was replaced by previous owner. How can I test if the cap is bad? Also, If I take it off what should I look for? I was told my 3.0 HO engine does not have points or condensor

 

[ConnieMarie]

Ordered a new dist cap and additional wires. Any help would be greatly appreciated. The pictures disappeared for some reason so I'll repost them.

 

[wcasey5]

Sounds like your needle valve and float are sticking open. I would take the top of the carb off and clean the valve and make sure the float is floating. That would cause a flooding situation and load up your plugs. You would still see gas going down the throat of the carb, but it would just flood over if the valve was stuck open. worth a try, and simple to fix.

 

[ConnieMarie]

What does this needle/float look like? I should mention only one plug had gas on it the other three were bone dry but had carbon build up. The wet one may have been from me trying to start the engine for an hour or so.

 

[Maclin]

The needle and seat and float are inside the carb, combined purpose is to regulate the level of fuel in the carb fuel bowl. Refreshed and adjusted during a rebuild of the carb. Operation is thus...Fuel flows into carb thru the seat, the float pushes the needle up into the seat to slow or stop incoming flow as the fuel level rises in the bowl.

 

[ConnieMarie]

Just wanted to update everyone...I ended up replacing the distributor cap which had slight corrosion, I was rather surprised since it had been replaced not too long ago. I noticed the electronic starter inside does appear to be a little rusty looking. Anyway the boat started up after the second try and taking the carburator filter off for better airflow and we were out on the water all Sunday. I did notice when starting and going from WOT to neutral is sounds like engine may stall if I were to let it sit. Anyway shes running now sounds pretty good too. Not sure if i should change the sparkplugs there seems to be mixed information regarding the 3.0HO engine.