OX66 LP Fuel Pumps

[fishinAK1]

Well I guess for now, I’ll run with the soldered wires until I remedy my problem. Then try to find a used harness system somewhere.
Should be fine for a bit...?

Another quick question. I’ve noticed on the port side of the plastic intake silencer, there are 2 vacuum line nipples. I only have one line to connect to it. And I’m pretty sure it goes on the lower nipple. To re-cycle unburnt oil. But is there suppose to be a line connected to the upper nipple?

 

[Sparkdog118]

on some yamahas the upper nipple is connected to the oil tank vent hose at the top of the oil tank. a good place to locate a used harness is superior marine salvage in bonita springs,fl. ask for jack and tell him sparky sent you. I have been buying parts from him since 1993. he is extremely knowledgeable and would have great insight on your situation. his number is 239-267-6722. he has everything and ships all over the country. I am lucky to have him in my neighborhood.

 

[Sparkdog118]

the red with yellow is the main positive for the injectors and the high pressure fuel pump in the vst. red yellow also goes to the o2 sensor. it is energized by the main relay. that is a constant positive when the engine is running. the purple wires are intermittent grounds that turn on and off to pulse the injectors. not sure if o2 sensor could be a factor.

 

[DennisG01]

Another quick question. I’ve noticed on the port side of the plastic intake silencer, there are 2 vacuum line nipples. I only have one line to connect to it. And I’m pretty sure it goes on the lower nipple. To re-cycle unburnt oil. But is there suppose to be a line connected to the upper nipple?

I can't imagine why your engine would be different than mine in this instance... the other nipple should have a tube connecting it to the throttle body. Without that attached you'll have rough running. I've only ever played around with taking it off while on a hose at idle and there's a noticeable difference. I'm not sure how it affects things, if at all, under load at upper RPM's. Look around underneath the bottom of the throttle body assembly - I'm pretty sure that's where it attaches. Probably just forgot to put it back on cause it went and hid from you!

 

[fishinAK1]

I can't imagine why your engine would be different than mine in this instance... the other nipple should have a tube connecting it to the throttle body. Without that attached you'll have rough running. I've only ever played around with taking it off while on a hose at idle and there's a noticeable difference. I'm not sure how it affects things, if at all, under load at upper RPM's. Look around underneath the bottom of the throttle body assembly - I'm pretty sure that's where it attaches. Probably just forgot to put it back on cause it went and hid from you!

hmm I’ve looked pretty good and can’t seem to find a line that would reach there... I’ll do some more searching. What ob do you have Dennis?
Thank you Spark, I will definitely call Jack to look for that bundle of wire harness.

 

[fishinAK1]

Oops looks like it might be for the oil tank overflow. Thank you!

fingers crossed and hands folded...gonna take ‘er out on trial again today.

...my family is breathing down my neck...we need our “escape pod” operational. Haha

 

[DennisG01]

I have a 2000 250HP OX66.

Do you guys not see my signature? It shows up for me, but am wondering if I am missing a setting to make it show up for others?

Yup - that's the one for the oil tank as you can see the other one already hooked up to the intake. Not having the oil tank hooked up won't affect anything you have going on... or at least I can't fathom how it would.

 

[fishinAK1]

Thank you JESUS!
We just took er out and honestly, running better than has in years!

....no surging, cruising #s better than ever, and 5400 rpm at WOT.

In the near future I do wanna replace that bundle of wires with an complete intact set. (Think a used salvage set is fine? Or know where I can buy this bundle new?) But for now it’s running!

I wanna write up a more detailed conclusion post later. But for now hallelujah and Thank you all the help and support on this thread!

 

[DennisG01]

I bet that feels like a HUGE lifted off your chest! But, there's a rule around here... it didn't happen without pictures! I think a picture of that ear-to-ear grin you had while running 5,400RPMs would suffice! I KNOW there had to be one!

Wiring... I'd probably just repair what is there. Kinda taking a chance on a used wiring set, you know? Use the "good" stuff... Ancor brand, adhesive lined heatshrink butt connectors. If you have to add any wire use "marine" wire - it will be tinned to be better against corrosion. Ancor makes that, too. If, when making a repair, you may be able to just replace the whole wire (starting at your butt splice close to the computer).

 

[fishinAK1]

I bet that feels like a HUGE lifted off your chest! But, there's a rule around here... it didn't happen without pictures! I think a picture of that ear-to-ear grin you had while running 5,400RPMs would suffice! I KNOW there had to be one!

Wiring... I'd probably just repair what is there. Kinda taking a chance on a used wiring set, you know? Use the "good" stuff... Ancor brand, adhesive lined heatshrink butt connectors. If you have to add any wire use "marine" wire - it will be tinned to be better against corrosion. Ancor makes that, too. If, when making a repair, you may be able to just replace the whole wire (starting at your butt splice close to the computer).

Sounds good. Ya maybe just cut out my solder joints and use good new wire and connectors.

How’s this for a victory pic?

 

[seasick]

That's great.
Now no futzing for a while...

So, the big question is..... What was the original problem source?

And what was that alarm?

Enjoy and good luck.

 

[family affair]

Congrats! Glad to see you made it to the end of the tunnel. I also can't wait to see the conclusion to what caused the problem to begin with.
Great way to start off the weekend!

 

[fishinAK1]

I think there were 4 smaller (ish) problems that that when combined, appeared as 1 large problem.

1) Rich running injectors (has never been cleaned/tested)

2) Bad O2 sensor (fuel mileage dramatically improved after replacing)

3) bad ignition coil (maybe slowly intermittently failing over years)

4) a small crack in the relay to injectors wire, that when got wet arced. Or pulling the plug wire charged the wet outboard and exited via the stainless LP pump screw that was coincidentally touching the wire bundle.

As far as the alarm, it was still below freezing here then. Even tho it was peeing, maybe there was a bit of ice in some part of water jacket and caused overheat alarm...idk.

 

[DennisG01]

Sounds good. Ya maybe just cut out my solder joints and use good new wire and connectors.

How’s this for a victory pic?

That'll work!

 

[Sparkdog118]

Awesome. That’s great!!! Time to get the family out n go fishing!! It is always a great feeling when the boat runs good.