Holley 2300 2bbl carb problem, OMC 5.0

[lmjpsl]

I scratching my head and seeking help.

I have a 1991 Seaswirl 190 I/O with an OMC 5.0 (302 Ford engine) and a Holley 2300 2bbl carburetor. Salt water had gotten into the gas tank and I drained the tank and rebuilt the carburetor. Now, the engine starts and idles fine. However, here are the problems:

1) The idle adjustment screw on the starboard side of the carburetor will kill the engine if turned all the way in. The idle adjustment screw on the port side does nothing to the engine if I turn it all the way in or even take it out.

2) If I accelerate the throttle (while on muffs), I will see gas coming from the carburetor venturi or the port side but no gas comes out of the venturi on the starboard side while accelerating.

3) When running the boat with throttle open to about 1800 rpm, a rich condition is present and black soot comes out of the exhaust.

I have adjusted the float. It appears to me that if it were a float problem, there would be a problem with both idle adjustment screws, not just one. I put in a 3.5 powervalve. I believe it is a vacuum leak somewhere. I sprayed WD40 all around the base and the carburetor without the carburetor increasing in rpm.

I'm hoping to find a solution.

 

[Offrddrver]

Any luck on this?

When you rebuilt the carb did you jet spray (carb cleaner through little red tube) every port on your metering block? And jet spray directly through the delivery hole linked to that venturi?
I've never had salt water issues, but I did have a white chunky buildup that got into the jets and metering block. I had to run a fine wire through the metering block and then "jet spray" the carb cleaner through every metering port hole....and the delivery port to the venturi for a good clean out. My issue was bad hesitation, but idled with no issues. Usually on my 2300 carb if I adjust either idle screw too much it can make the motor stall out, so that part of your statement doesn't surprise me much.
Long story short, my best guess, from my past experience, is that you still have a clog somewhere.

Why a rich state with only one side delivering......I don't get that one either.

I wish I had more for you, but I thought I'd give my 2cents because nobody else has.

Best of luck,

​Offrddrver

 

[lmjpsl]

Thank you, Offrddrver. What you have stated makes a lot of sense: still a clog somewhere. I'll break the carb down again and do an extra thorough cleaning. If that doesn't work, I'll just get another carburetor.

 

[Offrddrver]

On the metering block you probably noticed there are many ports/holes that all go together. I block as many as I can, shove the red spray tube in one hole and try to only allow spray to exit one hole at a time. Then block that hole and others and let the spray come out another hole. And so on and so on until every hole has been the entry and exit point (maybe overkill, but has not failed me so far). Basically a left side set of ports and a right side set of ports on the metering block.
Also, safety first, wear eye protection and spray in a very open area as the jet stream may go several directions at once.

Also spray through the port that goes through the venturi and make sure it is spraying as if it were spraying gas.

I always use an external tachometer (mine is an old school analog that I got for free...works great) There are some cool tach/timing guns on the market that may be a later option.
Anyway, I set my idle speed screw out until just touching the cam, and then adjust the Idle Mix screws gently all the way in, and then back out 1-1/8 turn on each side as a starting point. (in gear but no throttle after warm up)
Because my engine is running good these days I always move the Idle Mix screws evenly in ~1/8 turns.
In your case you can do bigger turns on one side or the other and watch the external tachometer to make sure adjustment is working. However, I'd always make the final adjustments by gently screwing all the way in, 1-1/8 out, and then even turns on left and right side until you achieve the peak idle RPM (Idle screws too far in will drop idle, then open evenly to reach peak, and then too far open will start to drop RPM again.) Adjust the idle speed screw, if needed, after that to reach a within spec RPM.
There is a full procedure to follow if you need more info, but just touching on the basics unless you need more details.

If you already know all of this......sorry so long.
If not, let me know and I'll be happy to help with step by step the way it works for me.

By the way I have a 1992 Four Winns 190 Horizon with 5.0L Ford with 2300 carb. I set idle at 600 RPM after warming up.
I run 122-60 Holley jets (as noted by Holley rep over the phone for Phoenix elevation). I have a set of 122-65's, but never installed them as the boat starts 1 key turn every time, and seems to run great at this time.

Best regards,

Offrddrver

 

[vasy]

Offrddrver, any way you can post a youtube on the tune up process?
Would be awesome to actually see the locations of the screws and hear the process.
Thanks

 

[Offrddrver]

No Title

I don't know, I've never tried to make a youtube video and I haven't tried to post any videos here either.
With my work schedule and my whole family in sports right now........it might be a long while. Sorry, but my boat may not be out of my garage (to put on the muffs or in the lake) for a month or so now that sports have started up again.

 

[vasy]

Good photo for a reference and a write up. Thanks!!!

 

[lmjpsl]

Thanks again, Offrddrver. Based on the image below, when I spray Gum-out Carb cleaner in number 16, it comes out of 20. However, when I spray number 4, nothing comes out of number 8 or anywhere else. I assume the clog is at number 4. I've tried the can air and the carb cleaner to unclog it but it hasn't worked. I guess I need to boil it in something.

1. Acc.pump discharge.	13. Fuel bowl vent
2. Main air bleed from main body.	14. Main air bleed from main body.
3. Main passage to discharge nozzle.	15. Main passage to discharge nozzle
4. Idle air bleed from main body.	16. Idle air bleed from main body.
5. Air bleed to main well.	17. Air bleed to main well.
6. Main body dowel.	18. Timed spark passage.
7. Main air well.	19. Main body dowel.
8. Idle feed restriction from main well.	20. Idle feed restriction from main well.
9. Idle fuel from main well.	21. Idle fuel from main well.
10. Idle transfer to main body to curb idle adjusting screw.	22. Idle transfer to main body to curb idle adjusting screw.
11. Curb idle discharge.	23. Curb idle discharge.
12. Powervalve channel restriction.	24. Powervalve channel restriction.

 

[Sparkinator]

If all else fails you can get a good rebuilt one at flying fish carbs. I bought one there a couple of years ago.

 

[lmjpsl]

Thanks to all for the help. Once I discovered that one of the holes on the metering block was clogged, I boiled the metering block for about thirty minutes in lemon juice. I tested it with the carb gum out and compressed air; the hole was unclogged. I reassembled the carb and now everything appears to work just fine: no more gas out of the venturi and turning the idle adjustment screw now stalls the engine.

 

[Offrddrver]

Great to hear, and best of luck with the final tuning.

Interesting to hear you had to boil it, smart move. I know salt water can clog things up quick just based on my snorkeling gear. I rinsed my snorkeling gear at the ocean, and weeks later pulled it out at the lake and I had salt deposits that I didn't even see weeks prior. (back in June/July)
My point here is that you may fight these salt deposits for awhile if the carb cleaner didn't even clean it up. It may keep clogging the small metering block holes until all salt in all lines are depleted. (I hope not for your sake.)

Have a great one.

Best regards,

Offrddrver

 

[Offrddrver]

By the way, thanks for the detailed metering block picture, that may help others in the future. I'll be saving that one for the future as well.

 

[lmjpsl]

Thanks a bunch.