RPM dropping too far when shifting into gear. 4.3LX (Gen +)

[bruceb58]

This is the problem when you have two threads going.

Figure out you choke issue on your other thread and then set your idle. Sounds like everything is good when your engine is warmed up.

 

[rderenzy]

yes, after 30 min of use, the "sputtering with light throttle is gone"
so what does that tell me? tells me carb doesnt need cleaned? or more likely needs cleaned? i really want this fixed

 

[HT32BSX115]

yes, after 30 min of use, the "sputtering with light throttle is gone"
so what does that tell me? tells me carb doesnt need cleaned? or more likely needs cleaned? i really want this fixed

Howdy, It should tell you once fully warmed up, and the choke is FULL OPEN (and out of the picture), that the choke may be all or part of the problem!

 

[rderenzy]

i see - i think i follow you - and because my choke is opening up in full BEFORE the engine is warm, that might be why i have that stutter?
so...how would i adjust that

 

[HT32BSX115]

i see - i think i follow you - and because my choke is opening up in full BEFORE the engine is warm, that might be why i have that stutter?
so...how would i adjust that

possibly. But not always. Your accelerator pump might not be providing enough fuel as you open the throttle too......

I am not a huge fan of automatic chokes. I disconnected it completely on my 1997 7.4L Bravo. I don't boat in cold weather so I never really have a problem starting when the engine is "cold".

Here's a pretty good video on adjusting an automatic (electric) choke though..... https://www.youtube.com/watch?v=gviih8tqKxc

 

[rderenzy]

ok i'll review that video, thank you
i checked the accelerator pump and it shoots pretty well

 

[achris]

Like I have already said in your other thread, richen the mixture screw 1/4 turn. That is not the screw that adjusts the idle speed. It's down near the bottom of the carb, between the barrels. 1/4 turn anti clockwise.

 

[rderenzy]

I'm trying that in less than an hour


hey question - take a look at this video - does this look to operate correctly?
https://youtu.be/O8wf9ll0w5g

If so I may be in luck - like I said yesterday when I gave it throttle it pushed down, fully opened and never came back
the throttle screw may have been way to tight. I could push down the choke to fully open (when boat was off) and it would NEVER return

 

[achris]

Cold engine with the throttle slightly open, that is exactly what we want to see.

Find some literature on basic carb operations and learn what each section does and how they relate.

 

[rderenzy]

Cold engine, throttle slightly open (not started) choke stays closed 100%
but I don't think its a choke problem

SO! back from the bay - started backing off the mix screw like you suggested - kept turning and turning, no benefit, must have turned a full 3 times
by the 4th full turn, It got better and better
must have made 6 full rotations (counter clock) and it was FIXED

or by that time was the engine warm so it was gonna be fixed? guess I wont know until next time

Played with the idle throttle - got the in gear idle down to about 650-700 later on the run

thanks for everyone's help - to be continued

 

[bruceb58]

Only adjust mixture screws engine is warm

 

[rderenzy]

well crap - when the engine is warm, I don't have that low throttle bog down issue - its a catch 22

 

[bruceb58]

well crap - when the engine is warm, I don't have that low throttle bog down issue - its a catch 22

Exactly...this is why you have a choke issue. It's not adjusted properly.

When it's cold, have someone shoot a video of the carb when you start it and we can see what happens when it warms up.

You should never have to have the mixture screws out 6 turns. You were compensating for a choke that wasn't on long enough when the engine is cold.

 

[Fun Times]

I want this closed I opened a new one w/ a more accurate title, here:
http://forums.iboats.com/forum/engin...putter-and-die

its got much better info

Yes lets go ahead and close this topic and keep the conversation within the other topic. One problem would be if we moved any to all of these posts over to the newer topic, it would be just one big mess to figure anything out as there would be about 58+ posts and a lot of them would be close to duplicate posts.

Again, here is a quick link back to the other post if interested, Just a little throttle makes the engine sputter and die

Thanks.