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40hp 402 Engine hickuping and gutless

I still cant get this thing to scream I can get it to scream adjusting that mixture screw with the idle lever fully open but u let it off and punch it up again and she accelerates slowly been dicking around it all day still cant get it to scream punching forward even when I punch it in gear she doesn't accelerate fast
whats wrong... least she idles with the lever half way up
 
I been ddicking around all day on and off

I cant get it to scream like it once did.. I also find I cant get it to start when cold without the idle arm fully open is that a problem

so here u see it doesn't do much but its idling
https://youtu.be/93HgsAbRAfE


here in this video I did what you said I think I did right.. while in gear adjust idle mixture screw till it trys to die then turn it back
https://youtu.be/g9Wk9x4XFx4


as I did try your half a turn if I do 2 turns she bogs when I get her to run high speed idle basically I'm basically around 1 turn from fully closed


or am I still doing something wrong and can the timing be off at all?
 
Mercs like lots of throttle when cold starting, so the idle lever should be all the way up. That said, you adjust the idle SPEED with the cold idle speed lever all the way down.

It sounds like your throttle cable is not adjusted correctly: With the engine OFF, see if the carb opens all the way AND the throttle arm returns all the way to idle.

Also, you need to stop shifting it into gear with the cold idle lever up--bad practice!

You're getting the hang of adjusting the idle mixture. Congrats! What you need here is to find the smoothest idle mixture, then add a 1/4 urn OUT (CCW) at a time to prevent bogging.

Jeff
 
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fastjeff said:
Mercs like lots of throttle when cold starting, so the idle lever should be all the way up. That said, you adjust the idle SPEED with the cold idle speed lever all the way down.

It sounds like your throttle cable is not adjusted correctly: With the engine OFF, see if the carb opens all the way AND the throttle arm returns all the way to idle.

Also, you need to stop shifting it into gear with the cold idle lever up--bad practice!

You're getting the hang of adjusting the idle mixture. Congrats! What you need here is to find the smoothest idle mixture, then add a 1/4 urn OUT (CCW) at a time to prevent bogging.

Jeff
Click to expand...

ok so with it off just shove it forward all the way I can do that and back
the reason I have the idle lever up is I have that stop screw all the way screwed in and 1 I cant idle it with it down or it shuts off so the lever has to be up to get it to idle... or is that a cable adjustment?

ill try toe cable adjustment now and ya she doesn't stop bogging when I punch it

what I was doing was it was in video as just me it idle then I punch it it bog I go back to neutral adjust the screw punch it again still bogs I go back to neutral adjust screw punch it again


so then this isn't timing problem this just cable and mixture problem then now

ill go try cable adjustment now
 
Add another 1/4 turn out (on the idle mixture screw, NOT idle speed screw). Your cables and idle up lever looks spot on.

Jeff
 
fastjeff said:
Add another 1/4 turn out (on the idle mixture screw, NOT idle speed screw). Your cables and idle up lever looks spot on.

Jeff
Click to expand...


I currently uploading new video.. reason I set the idle screw as you need to turn it all the way in to get it to idle.. I may take that nut off the ide speed screw and put it on the other side so I can force it that extra bit

ya I try another 1/4 more out it just stalls the engine.. I can get it to rev up in neutral idle arm she screams but she stalls the engine in gear punching it... ill post video
 
I got it running better but she still bogs down a bit
and I need a longer bolt for the idle adjustment

I play with the mixture screw in gear and turn it till it trys to stumbled than turned it back 1/4 turn and then i still having issues but she running faster

https://www.youtube.com/watch?v=k3iXE3zidOQ&feature=youtu.be
here my video

what next do i adjust or keep playing with the mixture screw
don't have a tach yet may take it out of another boat and hook it up
 
i tried the 1/4 more and then little bit increments but not getting it always fast

this best i got so far
https://youtu.be/EGotZ7FxLlk



and as for the idle screw is there a way to bring the lever back further or am i going to need alonger screw since i took the nut out

and couldnt get tach out since been raining but does engine sound running too fast or too slow idling?
 
try again?? works for me... what it saying

tomorrow going to be sunny so i gonna take the tach out

and would you know what setting to set the tach to for the poles for this engine.. and what the rpms should be in gear like 600 rpm?
 
ok i not sure if this right then
my tach doesnt have 12 it has 2 3 4 5 6 i set it to 6

here is my video
https://youtu.be/yAIhkQQ7_sk

now i thinking i still need more rpms but my idle screw is maxed out and yet idling too low? so i think i need to adjust that arm i pointing to in video its got threaded ends?
 
Do not run the engine past high idle without a load on the prop you will burn up the engine, it is the same as running low on oil. Did you check for spark with a open air spark gap tester? Have you done a proper throttle pickup adjustment? Adjust the slow needle 1 1/2 turns out preadjustment and then after the engine is fully warmed up final the adjustment in forward gear in the water. There is a throttle cam that keeps you from going WOT in neutral, with the engine off shift into forward and then you can open the throttle wide open. Depending on your serial number you need to do a proper sync and link and if you did not mess with max spark advance it should be good. What is the serial number of your engine?
 
With mercs especially you need to adjust the slow needle a tad rich to protect the engine in slow operation. Once you get a nice smooth slow idle adjust the needle 1/8-1/4 turn rich counterclockwise. It helps for cold starts and for the hole shot.
 
well if you watch my videos you would seen the dry run I did for showing WOT and the carburetor open and such..

and I dunno what you mean by a load the prop is in the water in the box so its under load is it not or you mean pushing the boat as opposed to shooting water out of the box


I haven't adjusted no spark.... and both spark plugs spark real well didn't need a tester just took it out grounded it and watched it high spark

I have don't the 1 1/2 turns out and then make it sluggish

I haven't adjusted the idle level arm... as you can see if its set for 6 on the tach for 12 poles if that's right it idles at about 500 rpms with that idle stop screw all the way out...

serial number is
7112761

ill post a new video of the dry WOT then you can tell me
 
and it starts up cold now first turn and she usually running... not sure what a throttle pickup is

and like I mentioned I only adjust the idle set screw there to try to get it to idle in gear as you seen in the last video at 800 -1000 rpms but the set screw only lets me idle it at 500rpms in gear.. or outta gear as you seen in the video I posted earlier today...

and how does no load on engine make it act like no oil is in the engine.. or low oil. if its getting the right mixture I figure maybe I having the right settings its just idling too low if you seen last video but I uploading new video of the throttle pos with it being off
 
here is new video i did with it off and in WOT you tell me if its done right i cant tell i got the engine off a person they told me it was running it wasnt really so i have had hell of time but least i got it idling smooother then what it orginally got it

https://youtu.be/TykAEB-AdlQ
 
Have you had it on the water? The best way to final the slow needle is after the engine is fully warmed up in forward gear. Whenever you rebuild the carb you must adjust the throttle pickup (engine sync) you have a 1978 and the throttle butterfly should just begin to open at 8 degrees after top dead center. Watch the butterfly on the carb as you advance the timing the carb should just begin to open at 8 DATDC. It looks like the throttle is fully open if you was to start it it would blow all the water out of your box and run away possibly throw a connecting rod. Preadjust the idle screw at 1 1/2 turns put it in the lake and bring it up to temp and adjust idle speed to around 650 rpm and then adjust the slow needle for the smoothest engine idle at the same time keep the idle speed around 650. First turn the slow needle in slowly 1/8 turn at a time and wait at least five seconds between adjustments. Turn it in until it stumbles and note that position then turn it out until it coughs. Your setting should be half way between those two points. Point it toward the big part of the lake and see how quickly it reaches WOT.
 
kimcrwbr1 said:
Have you had it on the water? The best way to final the slow needle is after the engine is fully warmed up in forward gear. Whenever you rebuild the carb you must adjust the throttle pickup (engine sync) you have a 1978 and the throttle butterfly should just begin to open at 8 degrees after top dead center. Watch the butterfly on the carb as you advance the timing the carb should just begin to open at 8 DATDC. It looks like the throttle is fully open if you was to start it it would blow all the water out of your box and run away possibly throw a connecting rod. Preadjust the idle screw at 1 1/2 turns put it in the lake and bring it up to temp and adjust idle speed to around 650 rpm and then adjust the slow needle for the smoothest engine idle at the same time keep the idle speed around 650. First turn the slow needle in slowly 1/8 turn at a time and wait at least five seconds between adjustments. Turn it in until it stumbles and note that position then turn it out until it coughs. Your setting should be half way between those two points. Point it toward the big part of the lake and see how quickly it reaches WOT.
Click to expand...

no I never had it in the river... I bought the engine stuck it on this boat I have a box I use to idle the boat in as you see so I don't need ears and that way I can shove it in gear..
how you adjust it and drive the boat by yourself... I figured could all be adjusted in the box...... not sure what a 8 DATDC is and I never set the advance not sure how... and why does the idle screw I have it screwed all the way out and I only get 500 rpms as you seen in the video... and ya I let it warm up in the box about 10 min of idling and then I play with the settings but still cant get more idle speed... unforntaully my trucks tranny I had to pull out and well that's another expensive story I need front pump housing and little expensive.. so no truck to get boat to the river... so I need to do this in the box... but its also hard to watch the buttferfly with that plastic cover infront of the carb.. and when I do start it the throttle is not fully open she doesn't blow the water out unless I punch it..... ill take another video today... as its supposed to rain this afternoon till Tuesday... so I only got a little bit of time... tired of all this rain my grass is like walking on a sponge... bu if you can tell me how to advance timing or know what 8 DATDC is or how to set it... and is my tach set right. to set it for a 6
I appreciate the help...
 
frigin rain I tell ya.. I made a quick video I didn't get much time I was dicking around adjusting the cable adjustment to try to slow engine down I still gotta have the idle stop screw all the way out if I get it down to 600 800 she wants to die... I did turn the screw out 1 1/2 and when I turn it in in runs smoother at around the 1 turn or 3/4 of a turn out from closed.. so I not sure its hard for me to adjust I find if I set it at 1 1/2 turns it doesn't wanna start if I don't have the stop screw set for 1000-1500 rpms idling she doesn't wanna stay.. or if I set the screw I loosen it and I have to pull the throttle lever back it seems to stick for idying I hope tommorw no rain.. as they call from now till Tuesday
but here is video I got it was raining and I had to quick it was down pour after I did it..

also when I took first video other day I used the 1 stator wire for the tach.. today it didn't work.. but the other stator yellow wire worked today... does that mean stator not working right as should it be working on either yellow stator..
well here is the video sorry its short and not in detail didn't get time damn rain

https://youtu.be/EzAwql9WaW8

and is there a video or you could make a video on how I set this video... as I really don't wanna take it to shop they $125 an hour and 3 weeks behind

and pictures videos for this engine be great
 
In the beginning of the video, before you lowered the idle speed, it was idling fine. Get it to idle at that speed again, then adjust the stop so it won't go lower. Next, put it in gear and find your best idle setting (using the carb idle mixture screw). Take your time with each setting, letting the motor settle out for at least 5 seconds. When you have the best idle setting, add 1/2 turn OUT on the carb mixture screw and go boating.

Note: Those are not the best idling motors and will be okay with a 1,000 rpm idle for shifting. Do it all the time with mine.Jeff

Jeff

PS: For some dumb *ss reason, some tachs will only work off one of those yellow wires coming from the stator. Seen it several times.
 
fastjeff said:
In the beginning of the video, before you lowered the idle speed, it was idling fine. Get it to idle at that speed again, then adjust the stop so it won't go lower. Next, put it in gear and find your best idle setting (using the carb idle mixture screw). Take your time with each setting, letting the motor settle out for at least 5 seconds. When you have the best idle setting, add 1/2 turn OUT on the carb mixture screw and go boating.

Note: Those are not the best idling motors and will be okay with a 1,000 rpm idle for shifting. Do it all the time with mine.Jeff

Jeff

PS: For some dumb *ss reason, some tachs will only work off one of those yellow wires coming from the stator. Seen it several times.
Click to expand...

ok ill try again later today if its not raining... at the moment I could put the boat in my basement as I cant slow down the water... called insurance as I got water coming up cracks middle of the house so that's not good don't want a sink hole house...

so do I get it to idle it at 1000 rpms in gear or out of gear. I'm guessing out of gear... if I set the mixture screw at 1 1/2 turns I know it wont start unless the throttle idle lever all the way up and it will stall once you slide back down the lever and put it in forward gear. that's why I was having in neutral and id set the mixture screw when it started to run faster.... and then die that's where I set it back...
so those 2 stop screws on the right side one be the WOT but whats the other one for?

another question.. why do I have to dial that idle stop screw out all the way taking that nut off as you see.. is something set wrong..

and last question if I set the set screw all the way out to idle at like 1000 1500 rpms on its own when I loosen it to want to slow it down.. it wont come back unless I take my fingers and pull it back it will stay at the speed.. whats causing that... would that be the throttle adjustment cable I need to make it more sloppy? but whats confusing why I need to set that idle set screw all the way out to get it to run I figured if I set it all the way out that thing should be running at 3000rpms where I have that screw all the way turned in


back to shop vacing ill try to play again today.... my Chrysler and envinrude where this hard to set lol
 
Your remote control cable should be adjusted so it JUST closes the throttle all the way with the cold start lever all the way down and in neutral. Some people stick a piece of paper under the stop and, if the paper can be removed without tearing it, the adjustment is correct.

Jeff
 
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