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40hp 402 Engine hickuping and gutless

C

comet424

Regular Contributor
hi I have a 40hp 402 engine..
I put a new carb kit in... I checked the filter its clean I checked spark I got lots

but the engine doesn't wanna idle and when I rev higher in neutral she hickups kick backs and cant rev fast... what be wrong what can I do

I even adjusted the idle screw best I could do to seem to get the most rpms

here 3 videos I have made best I could do
https://www.youtube.com/watch?v=7rC3qKHBcPw
https://www.youtube.com/watch?v=fUZ4_bCM98k
https://www.youtube.com/watch?v=R7_qYOC4E-o

maybe you guys can figure whats wrong
 
First of all, adjusting the IDLE mixture screw doesn't effect such high rpms as you were running it at. Slow her down as low as possible and find the best idle mixture setting (start at 1 1/2 turns out). And, since you have such a huge test tank, put it in gear and reset the idle mixture screw.

You're close to having a good running motor.

Jeff
 
fastjeff said:
First of all, adjusting the IDLE mixture screw doesn't effect such high rpms as you were running it at. Slow her down as low as possible and find the best idle mixture setting (start at 1 1/2 turns out). And, since you have such a huge test tank, put it in gear and reset the idle mixture screw.

You're close to having a good running motor.

Jeff
Click to expand...

ok ill try again so turn the screw all the way in... the idle mixture and turn it out 1 1/2 turns
and its the only tank I had.. why is it too big? and right now I cant get it to idle I can turn that damn screw almost all the way in ill take another video

and why is it so sluggish when I reve the engine.. I figured it was running on 1 spark plug yet they both running... ill try again and put in gear and take a video ill get back to ya

I appreciate the help
 
I uploading video to youtube so gonna take a bit... but I closed the idle mixture screw and turn it out 1 1/2 turns choked it and had to reve throttle up to get it started
it still hickuping youll see In video... . I turned down the rpms somewhat and I turned the screw in a bit I tried putting it in gear but she stalls right out.. not enough rpms

not sure do I adjust those linkages or what but I gonna turn the idle stop screw all the way in so it will run faster and ill get back to you too
 
First of all, that leaky fitting at the tank is allowing air to be sucked in--and that's bad (messes up the carb settings). ANd that the bulb won't get hard means the check valve inside the bulb is leaking back tot he tank. Try another one.

The way it 'dive bombs' when it idles a bit too low, or too long, can be either carb idle mixture setting, or possibly a bad top crankshaft seal.

In the video you didn't adjust the idle mixture screw, just the idle SPEED screw. That's the one you need to work with now.

Hang in there! She starts up fine (a good sign) and seems to be close to a good runner.

Jeff
 
fastjeff said:
First of all, that leaky fitting at the tank is allowing air to be sucked in--and that's bad (messes up the carb settings). ANd that the bulb won't get hard means the check valve inside the bulb is leaking back tot he tank. Try another one.

The way it 'dive bombs' when it idles a bit too low, or too long, can be either carb idle mixture setting, or possibly a bad top crankshaft seal.

In the video you didn't adjust the idle mixture screw, just the idle SPEED screw. That's the one you need to work with now.

Hang in there! She starts up fine (a good sign) and seems to be close to a good runner.

Jeff
Click to expand...

ok so in the first video at 2:33 I adjusting the mixture screw isn't that what you mean how do you set that right?.... and how would I know if its crankshaft seal?

as for the bulb that's a brand new hose and bulb and the tank should never be leaking like that then so that's bad?
ill retry in 2nd video u see its in gear.. is that too fast sounding..
and no I haven't done the fuel pump seals.. is it just a diagrapham kit like a brigs and straton engine fuel pumps?
 
I uploading a video to you tube gonna take a while its 9 min long... I played with the setting mixture from 1turn to 1 1/2 in between... I tried in gear it still gutless... I turned that set idle screw all the way.. need to take that nut off so I can screw it farther in.

tank was getting stiff ill try my other tank tomorrow it has a 1 connector style on it... as this is a brand new hose etc..

battery I guess dead as it wont turn over now.. sooo I not sure whats wrong... least it runs lol

but never did fuel pump yet but still misses
frustrating I tell ya lol

stay tunned for my 9 min video as I show me adjusting etc
 
You're still not adjusting the IDLE mixture screw; the one you're playing with is the idle SPEED screw. The one you want is in the carb, accessible with a long thin slotted screw driver.

Jeff
 
ok if in pic 1 you see if isn't the mixture screw you seen me turning in the 9min video or the other videos then what is it? as I was turning that screw 1 1/2 and 1 1/4 turns... and if that's not the mixture screw then are the 2 2 screws on the side there that are glued in
 

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as I getting frustrated why its running rough if you say that's not the screw I'm adjusting in the video so I dunno what other screw is there.. as you see that screw driver in the engine as the engine is running and I just turn it slightly the other one I need to take the nut off is just to keep it reving the rpms higher in netural
 
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I did compression test... Top cylinder is 150psi and bottom cylinder is 148 psi

gonna pick up a fuel pump diagram kit today hope that helps
 
Good compression numbers. The screw with the screw driver in it (top photo) is the one you're after. Start at 1 1/2 turns out and adjust with her in gear.

On the fuel pump issue, good idea to replace the diaphragm--had one go on a 402 I worked with.

Jeff
 
fastjeff said:
Good compression numbers. The screw with the screw driver in it (top photo) is the one you're after. Start at 1 1/2 turns out and adjust with her in gear.

On the fuel pump issue, good idea to replace the diaphragm--had one go on a 402 I worked with.

Jeff
Click to expand...

ah ok do ui need this other kit I seen called the check valve kit looks like it comes with those metal things or is it ok for the diaphragm kit?
as I seen it u can get either or... or the check valve doesn't go bad?
ah ok ya in like the 9min video and couple other videos I adjust that damn screw between 1 turn and 1 1.2 turns but if I start at 1 1/2 turns do I open it a bit more or do I close it... as I still cant punch it with the high idle to go from slow to fast in seconds u see it sluggish

and I not sure if I need this check valve kit or if the diaphragm kit good enough I picked up... and could it be the engine not timed right? it seems the bigger engines I worked on the 200hp merc the 115 chrysyer 115 evinrude engines were easier to tune then these smaller engines lol
 
havent opened diaphram kit yet.. but how do you know if you need a check valve kit.. as its same as the dipfram kit just has extra metal part it looks like.. and wouid that cause engine to surge like you seen in videos? or how can i test oringal as you seen the fuel pump taken apart in the last video
 
so I finally got the diaphragm kit with the valve in it... the kit comes with 2 valves... do I need both.. as you seen in last video only 1 in there.. and how do you know if that person before me put the valve in the right way.. and that maybe I need both valves in there..

anyone have pictures on how it goes assembled
 
ok so you seen in my last video here it is again
https://youtu.be/Lzqr1lkvG1Y

I not near the engine this afternoon.. but is 2nd one missing then or do the 2 fit on each other or so...
as you see there is a 2nd hole but nothing in it... does that check valve go in there... and if they only go in 1 way... is there a Left and Right.. so like 1 sucks wont blows kinda thing.. where I wouldn't want the 1 check valve that suspposed to suck in the blow side and vise versa

or are they both exactly the same?

is there a pic of how they supposed to sit and such as I don't know how it exactly goes if last person has done this wrong
 
you need both check valves....I only skimmed your video - and you may have both....loosen the two S/S screws inside the pump's housin to
free the valves....they are the same but installed 'opposite'....if you get them backwards, the pumps will not move fuel to the carb....
 
I came home and looked at it.. only can go one way and i guess you flip around for other.. i tested the old ones they seem to be ok..but ill use new ones i blow on them and they push open but u gotta use enough force blowing on it to pop them open...

well hopefully that will fix it the new ones..

hopefully it will run after this smoothly since i did carb kit .. cleaned fuel filter and now this fuel pump
 
and i wasn't sure if they both the same valves.. as there is a stamp number 2 on them figured there is a 1 and 2... but both were "2" stamped on it...
heres hoping that wlll fix the engne kicking and sluggish
 
ah ok thanks
i gonna install it today... so if this doesn't fix the sluggish engine no power right when you punch it in the high idle lever.. or the engine kicking back misfiring what else be wrong
 
i currently uploading youtube video 2min one

so changing the fuel pump kit made it run it isn't kicking miss firing.. what is the pin hole in the fuel pump area i took a pic

so i was able to set the high rpms with the idle throttle all the way open and adjusted the mixture screw till it screamed as a little one way either direction bogs it down... but still has no power... i had screwed the idle stop screw all the way in to get it to idle and it idles and runs in low gear but when you try to punch it she stalls out...and do i do any adjusting on the linkage for the controls.

but if you can let me know what else to adjust i figured the threaded arm in the video by the stator
but not sure
or is it more adjusting of the mixture screw
 
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