Mariner 150 V6 Carb Question

[zookimota]

Pulled the carbs off of Mariner V6 and found bowl vent jets missing in a couple of places. Top carb had both, center only had one, bottom had none. This thing was running like crap. Couldn't throttle it over idle at all or it dies out. Checked compression and its pretty even at 100-105 per and fires on all 6 evenly. Removed idle stabilizer. Checked timing, Carb sync seemed correct. New fuel pump, new fuel line and connectors. Cleaned and checked tank check valve. Starts right up but that's about it. On a hose it sounds good, but it won't pull the boat off the trailer or even get above about 1600 without dieing back. Even on a hose, if you bring it up to about 2500, it starts to sound like its dropping cylinders, but spark is still stong on all of them when it does this.
Could the bowl vent jets be causing this? Or have I got something else going on? Noticed one bleed line (#2) constantly has a bunch of fuel in it. Pulled it off at the cyl end, and it did change the idle slightly like it was leaning out more.
If the vent jets are it... where the heck did they go? They weren't anywhere to be found.

[half fast]

It is common for mercury to leave them out on certain motors.Sounds like a stator issue.Give us your ser # . hf...

[sosmerc]

The vent jets (sometimes referred to as "back-draft" jets) don't come into play until mid-range. Merc has experimented with different vent jets in search of better mid-range economy. You should be able to leave them all out without creating any real problems. Generally, cylinders 2 and 5 tend to run the leanest....so therefore many of the carb setups did not use vent jets in 2 and 5.

[zookimota]

S/N is 5316752.
What kind of tests can be performed on the stator other than regular ohm tests to confirm this is the problem?
Going through the carbs tomorrow.
Haven't done any testing of electronics other than verify spark and timing.

[zookimota]

Cleaned all the carbs, found no problems.

Checked OHM readings on stator and it checked out OK.

When checking trigger, I had one test that ran about 1484 while the rest ran about 1322-1325, so I am replacing the trigger. Also noticed that while the readings were being taken, that if you moved the wire harness for the trigger right where it goes under the flywheel the OHM readings would change, mainly on the one that was too high.

Hope this fixes it.

[Alan Power]

Zookimota, I have exactly the same symptoms, except when I nail it the engine bogs deeper momentarily and then snaps to life.
Does this happen to yours?

BTW; no vent jets in my carbs either, (WH 15's)

Alan

[zookimota]

This thing would just bog down and just die. Never could get it come out of it at all!!

I hope the triggers help because I can't find anything else that might be causing it. When it dies, you can hit the key and she'll start right back up.. wind up like heck on the warmup, put it in gear either forward or reverse and it will idle like that as long as you wanted to, but hit it (anything over idle) and it is over. If you're lucky you can maybe get it up to 1500 to 1600 before it dies back out.

I'll keep you posted when I see what the triggers do for it.

[mercmatt22]

Ohm tests will lie to you sometimes on a stator if you have spark on all 6 your triggers should be ok. you need to do a voltage check on the high speed side of the stator (red wires) you need a dva meter to check the voltages.

[zookimota]

Had just a little time this afternoon so took it to the ramp and left it on the trailer. Powered it up full throttle and it pulled strong. Enough to push my 3/4 ton pickup with the emergency on and in park about 6 inches up the ramp. 1000% better than it was before.
Since I had noticed the ohms change on that one trigger reading when you would move the trigger harness where it came out of the ring, I'd bet that was doing some funny stuff everytime the advance was moved.

Will get a better run out test later, but for now it appears to be somewhat healed!

[Alan Power]

Glad it worked for ya, will look at mine tomorrow. It's been raining all week, hope tomorrow is nice? Thanks for your input,
Alan:D