50hp mercury starving of fuel

Hey guys got a little issue here with my 1982 50horse outboard. Few month ago I redid de carbs and changed the gas tank on it. It work great out side the water and the day I took it fishing it started no problem got out of the harbor no problem(20min at 5mph) then I speed up to go to the grounds I got there but when I troutle down to check the fish finder it didnt want to stay at low rpm and it would die. It was a strugle to get it to turn on again and when it would turn on its idle would be off and it would die when put in gear untill I tricked to hit high rpm with the choke once it was at high rpm it would run great like nothing happened. Then when I got to the harbor it would only go at 4mph if I opened it more it would die. So at home I did the carbs again thinking I might have done them wrong even following the parts schematic. And there it was started like a charm at home same thing out the harbor and to the grounds but it did it to me again. Though this time it was harder to get it to start and it wouldn't idle. I got it to turn on by priming the carbs passed full while cranking and I would only stay alive if I kept applying choke on and off on my way back so yeah it was fun..... I check the compressions and they're all very very close to 120 so the heads are fine. Can any one help me out here??
I'm thinking redo cards and go back to old gas thank??

Hey kimcrwbr1

thanks for the reply!
I don't have a manual
yes they are. i tightened down the linkage when they were both in the close position.
no I haven't check the ignition timing and throttle opening haven't touch that before ill provably read up on it to see how its done.
and if the low speed needle is the same as the idle tube? the tube i just tight it down, the idle mixture needle i just made note of how many turns it was away from tight position. so before i took them off they were 3 halve turns to tight, when i put them back i went all the way in then backed up 3 halve turns.

yes when i did them the first time i changed all the gaskets, bowl seal, few washers. the second time i took them ALL apart and soak all the medal parts in seafoam over night.
i didnt resurface it though thats something ill do next, but yes i did install the base gasket and thinking about it i usually do tight stuff down really night. should i get a new repair kit set?

been reading around and found the timing instructions but for the primary pick up directions ill have to have the engine running...

Sounds to me like the idle adjustments are way off.

Here's the deal: Most OB carbs lack an accelerator pump, so getting the idle mixture right is critical. A bit too lean--though it may idle okay--will cause severe bogging when the carb(s) are opened. For this reason, adding a 1/2 turn richer on those idle mixture screws cures a LOT of problems.

Jeff

Thanks Jeff ill play with that needle cards to see if it comes on. It kinda puzzles me because it was working just fine after the carb build but then it gives up..

So I plaid around with the needles but that didn't change it. Right now its having trouble starting. Its almost like it fires enough to disengage the starter then dies. Does that for a bit then I prime the carbs until they squirt and it'll stay on with rough idle.as soon as I open the throttle it chokes and dies. I pulled the carbs again I'm going to lightly sand the base and the gas pump to see what that does. I have a feeling its a vacuum problem.

Have you adjusted the carb idle in gear, warmed up (preferably with the boat on the trailer or tied to a dock?) AFTER you get the carbs to idle best, THEN you add the 1/2 turn out on the mixture screws.

Jeff

Thanks guys. So I lightly sanded down fuel pump diaphragm and base of the carbs it did need some sanding cuz as i sanded it on an even surface you could see where the sand paper didn't hit. So I put it back together and it started beautifully. I tested High RPM once and I think it hesitated a bit (hard to tell) before winding up. Ill be trying this out when I put it in the water I don't like running high rpm with muffs.. Should I rent the timing light just to make sure its in good link?
And would the bad surface have been the problem or should I go back to the old thank any ways??

You can borrow a light from Auto Zone. Time it about 21 degrees max at WOT. (A setting of 23 is recommended, but I ate a couple of pistons with 23 degrees--modern crap gas!)

Jeff