Boat kills and loads up in reverse only. need help

[89 Z22]

1.) 1st Problem-
I have a 460 OMC and starts and runs perfect other than reverse it loads up and kills and smell like raw fuel. If I hold it wide open it will stumble and clear out and work for a little in reverse.

2.) 2nd problem-
Also when I start boat for first time it idles low. Then i get up on plane and cruise to channel it won't idle down like when I first start it. Then I turn it off and back on and is just fine and idles down. Any ideas. I had the carb off and cleaned and was the same. However we didn't totally take it apart and clean it. Also it doesn't look like a stock carb. Sorry I wrote a book.

Thanks for any input I am very very thankful for all the nice people who help me.

[BUIZILLA]

item 1 is a misadjusted shift interrupter, it's running on 4 cyls sucking the fuel of 8 cyls

item 2 is a sticking choke release cam arm, and misadjusted cold idle screw contacting that stepped cam

[zelatore]

Wow - that's what you call a precise response. About the only thing better would be if you went out and fixed for him!

[cobra]

I'll offer two other possibilities:
1-water pressure loading up the exhaust, maybe making its way into the cylinders.
2-Carburetor secondaries not closing all the way, more likely if it's a vacuum secondary carb.

[Planetwarmer]

I'll offer two other possibilities:

2-Carburetor secondaries not closing all the way, more likely if it's a vacuum secondary carb.
If the secondaries are sticking open, how do you remedy the problem?

[cobra]

Depends on the cause and carb type; corroded/sticky shaft, weak spring, hardened diaphragm... Sometimes you can just work the shaft by hand a few times and free it up. I've only had one ever that I couldn't fix 'properly' (Holley) so I just tweaked the manual return linkage a bit to force it closed. The linkage normally only closes it most of the way and it's supposed to finish shutting on its own. Being that his is only sticking after a hard run and is going back to idle after a shut down, it's the first thing I'd check. Killing the motor stops the vacuum that may be holding the secondaries.

Diagnosing the reverse problem depends on if it acts up immediately upon shifting or only after it starts backing and if it always does it.

[89 Z22]

THAT'S EXCELLENT!!! Thanks for input. I am happy to see I gave you enough symptoms to give me some ideas on what to try and such. Come spring I will look into a few of these things and see where it gets me. I like to have ideas before I have a tech look at it so I am not taken for a ride with a open checkbook. You guys are great!


Wow - that's what you call a precise response. About the only thing better would be if you went out and fixed for him!

[mrfixxall]

if it is water injestion make sure you have fogged the enginf really good b4 you put it away