2K sputter
11-14-11, 09:00 PM
#26
Yeesh, can't imagine driving one of these things through a winter up there.
The problem is that the stuff that really needs cleaning is inside the carb. You can't get to it from the outside. You can remove the plugs on the sides of the bowls and attempt to toothpick and spray the jets while still on the car as Kentetsu suggested, but that sounds like more trouble than just removing the carb.
Maybe one thing to try is running straight Seafoam through it. They make a spray version that you could shoot right into the main fuel line. Or run a higher concentration of the liquid stuff and give it hell. I usually run a full bottle with about 1/8 of a tank.
The problem is that the stuff that really needs cleaning is inside the carb. You can't get to it from the outside. You can remove the plugs on the sides of the bowls and attempt to toothpick and spray the jets while still on the car as Kentetsu suggested, but that sounds like more trouble than just removing the carb.
Maybe one thing to try is running straight Seafoam through it. They make a spray version that you could shoot right into the main fuel line. Or run a higher concentration of the liquid stuff and give it hell. I usually run a full bottle with about 1/8 of a tank.
11-15-11, 12:06 AM
#29
Oil Leak
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Car sat for 4 weeks while I was arranging a rear axle. It's since been gone through about half a tank (sea foam included at fill up)
I might try adding another can of seafoam when i hit a quarter tank.
I might try adding another can of seafoam when i hit a quarter tank.
11-15-11, 07:21 AM
#30
Lives on the Forum
Great Scott... BEANS! I didn't even realize that he said he gave it beans! You can't put beans in the carburetor! It just won't work. Good thing you noticed that 
Back into serious-mode... I take it you think his primary jets are clogged. I can see that being at least part of the problem. But if he "gave it beans" then the accel pump should be keeping it rich long enough for the secondaries to open. So I think there's more going on.
I wouldn't do this procedure with the carb on the car. For one, the bowls are going to be full of fuel. When you remove the caps, it's gonna be all down the side of your motor. Two, the bowl facing the rear is über-hard to get to with the carb on the car and all the linkage attached. Better off removing the whole thing and even pulling the air horn to completely clean out the bowls. There's a little hole in the bottom of one that feeds the accel pump. It acts like a clogged drain when there's crud down in the bowls. Some pics here: https://www.rx7club.com/1st-generation-specific-1979-1985-18/how-test-nikki-fuel-jets-without-rx-7-a-964299/
Back into serious-mode... I take it you think his primary jets are clogged. I can see that being at least part of the problem. But if he "gave it beans" then the accel pump should be keeping it rich long enough for the secondaries to open. So I think there's more going on.
I wouldn't do this procedure with the carb on the car. For one, the bowls are going to be full of fuel. When you remove the caps, it's gonna be all down the side of your motor. Two, the bowl facing the rear is über-hard to get to with the carb on the car and all the linkage attached. Better off removing the whole thing and even pulling the air horn to completely clean out the bowls. There's a little hole in the bottom of one that feeds the accel pump. It acts like a clogged drain when there's crud down in the bowls. Some pics here: https://www.rx7club.com/1st-generation-specific-1979-1985-18/how-test-nikki-fuel-jets-without-rx-7-a-964299/
I like to recommend the toothpick technique because it gives the guy fewer chances of screwing something else up by tearing the carb apart. Last thing we want to do is introduce another issue while trying to assist in troubleshooting. And pulling the fuse for the fuel pump and allowing the carb to run empty solves the problem concerning fuel in the bowls.
11-15-11, 08:21 AM
#31
Oil Leak
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Anyone have pictures/directions more specific to cleaning the jets with the carb still on? The most complicated carb I've ever worked on would have to be a .60 OS model 3d helicopter enegine
11-15-11, 09:43 AM
#32
My money's still on the AP/transition circuit... of course, I could fudge that by pointing out that the primary jets are PART of the transition circuit. But that'd be cheatin'.
Reason I think so is that he stated that, "If I ease on the gas up to 2k. It will momentarily stutter at 2K, then climb above... from there on out it responds to the throttle like it should."
He wouldn't get proper throttle response above 2k if his main jets were clogged - - he'd get leaner and leaner as throttle is advanced. The transition from idle to about 2500rpm or so is covered by the transition circuit & the accel pump. Easy slow advance past high idle is mostly t-circuit; fast pedal dumps are mostly accel pump.
If he's got a stock unstripped carb, with the whole dashpot/throttle opener, teeter/totter assembly covering access to the rear bowl's service ports, it's far more work to try to get the bowl plugs out with the carb installed than it is to pull the carb. Getting those items properly back on the carb without dropping or losing anything is quite difficult without face-on access to the rear of the carb. Many deep-recessed screws and such. IMHO.
He could even forego disconnecting the throttle cables; just unfasten the carb and rotate it, then park it on top a board placed over the engine.
MUCH easier to work on the backside bowl that way, if undoing everything is too much.
Reason I think so is that he stated that, "If I ease on the gas up to 2k. It will momentarily stutter at 2K, then climb above... from there on out it responds to the throttle like it should."
He wouldn't get proper throttle response above 2k if his main jets were clogged - - he'd get leaner and leaner as throttle is advanced. The transition from idle to about 2500rpm or so is covered by the transition circuit & the accel pump. Easy slow advance past high idle is mostly t-circuit; fast pedal dumps are mostly accel pump.
If he's got a stock unstripped carb, with the whole dashpot/throttle opener, teeter/totter assembly covering access to the rear bowl's service ports, it's far more work to try to get the bowl plugs out with the carb installed than it is to pull the carb. Getting those items properly back on the carb without dropping or losing anything is quite difficult without face-on access to the rear of the carb. Many deep-recessed screws and such. IMHO.
He could even forego disconnecting the throttle cables; just unfasten the carb and rotate it, then park it on top a board placed over the engine.
MUCH easier to work on the backside bowl that way, if undoing everything is too much.
11-15-11, 10:23 AM
#33
Lives on the Forum
You're probably right about pulling the carb DD. I just didn't want to advise him to tear the carb apart yet. I still think that the most likely culprit is the jets, mostly based on my own experience with that issue. If he can clean them, or at least confirm that they aren't the problem without tearing the carb apart, then chances are he won't create other problems while trying to fix this one.
If the jets are clear, then a full rebuild would come next.
.
If the jets are clear, then a full rebuild would come next.
.
11-15-11, 10:25 AM
#34
Sounds like a plan Divin. I'll keep that trick in mind next time i wanna windex my float windows lol.
As for the acl pump fix, I'm fairly certain that you can work on the pump with out dismantling the carb. I believe the first time I ever worked on my carb, the acl pump was one of the first things to come apart.
As for the acl pump fix, I'm fairly certain that you can work on the pump with out dismantling the carb. I believe the first time I ever worked on my carb, the acl pump was one of the first things to come apart.
Last edited by Jingkun; 11-15-11 at 10:27 AM.
11-15-11, 10:32 AM
#35
Oil Leak
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You've all got me so excited to gut this thing... Can someone please snap a few pictures showing me what to stick where so I can attempt to clean the jets? Anyone in the MN area want to come help out? I wouldn't be opposed to stripping the carb down to barebones.
11-15-11, 02:42 PM
#36
You're probably right about pulling the carb DD. I just didn't want to advise him to tear the carb apart yet. I still think that the most likely culprit is the jets, mostly based on my own experience with that issue. If he can clean them, or at least confirm that they aren't the problem without tearing the carb apart, then chances are he won't create other problems while trying to fix this one.
If the jets are clear, then a full rebuild would come next.
.
If the jets are clear, then a full rebuild would come next.
.
-Gamah, I'll see what pix I have tonight, but as you're running an '83 you might want pix to come from someone with a closer year match. Some of the outer bits changed a good amount between 80 and 83.
Only semi-tricky parts on my build is 1) getting the left rear carb hold-down nut (need a shorty wrench or something with a lot of offset) on and off, and 2) pulling the carb without breaking the altitude compensator, which I believe isn't even in the same place on an 83 carb. Rest of it is just making sure you remember where all the hoses and connectors go, and being very careful not to break your OMP lines.
Oh,and don't drop the hold-down nuts on the left side... they can go bad places when dropped. Cover the manifold opening once the carb's off it.
11-15-11, 05:24 PM
#38
I think on the 83 it's up on the side of the carb, rather than on the manifold, so probably not an issue in any case.
On the SA's they are on the lower manifold, made of 1/2 metal, 1/2 plastic, connected with a very stiff u-shaped hose, and the hose nipple can snap off real easy.
On the SA's they are on the lower manifold, made of 1/2 metal, 1/2 plastic, connected with a very stiff u-shaped hose, and the hose nipple can snap off real easy.
11-15-11, 09:35 PM
#40
Oil Leak
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Seriously, anyone in the MN area want to help? You will be compensated for your time. Or if I do pick up a core, is there anyone I can send it to for a rebuild?
11-16-11, 04:26 PM
#42
Lives on the Forum
Yep. Probably your best available option since Sterling is not currently active...
11-17-11, 05:34 PM
#44
I was intimidated to touch my carb to the point I sent it off to a builder ( who shall remain nameless) after getting the shaft for a bout a year I finally bought 2 cores for practice. I read, re-read and then read again how to properly rebuild my Nikki. I bought myself a 6 pack and spent the whole day dismantling my Nikki labeling everything and taking pics like crazy. The only hard part is modding the linkage IMO.
http://www.sterlingmetalworks.com/
if you need a additional help shoot me a pm
11-17-11, 05:52 PM
#45
Oil Leak
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http://www.youtube.com/watch?v=d6IJUwOxhUs
More detail... this was after a 30 minute drive home
Also it refused to start back up just then... I've a weak battery.
It looks/acts like I let off at 15-1800 but i'm keeping my foot rock solid
Note: in the mornings with the choke on and idling high at about 1200 throttle response is instant
More detail... this was after a 30 minute drive home
Also it refused to start back up just then... I've a weak battery.
It looks/acts like I let off at 15-1800 but i'm keeping my foot rock solid
Note: in the mornings with the choke on and idling high at about 1200 throttle response is instant
Last edited by -Gamah; 11-17-11 at 05:54 PM.
11-17-11, 08:37 PM
#46
by the video it really seems like something is clogged. I could be wrong but no one will know until you open the carb up. You have a forum full of a bunch of guys who are willing to help but you need to take the first step bro.
Take that bad boy apart!
It's probably been a while since it's been rebuilt.
You have a forum full of a bunch of guys who are willing to help but you need to take the first step bro. Take that bad boy apart!
It's probably been a while since it's been rebuilt.
11-17-11, 08:57 PM
#47
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When do you want me to swing by and give you my nikki? I'll help you put it on and see if it does any good. But its gonna have to be soon. Snows on the way.
by the way, this is VERY similar to what my dellorto did before i rebuilt it. http://www.youtube.com/watch?v=lpkn7QNByyw Under 3k, if i jumped on it, it would bog and die or bog and take off depending on where i was at in revs. Clogged main jets (doesnt work like a nikki, but main jets are still main jets) was my issue, after the rebuild I've had no issues
Also the reason its fine with the choke probably has something to do with the way it operates. When the plate closes (choke applied) its cutting off air flow, making the car run richer. Since its running richer to begin with, the demand for fuel when you jump on it isnt as big, so no bog.
by the way, this is VERY similar to what my dellorto did before i rebuilt it. http://www.youtube.com/watch?v=lpkn7QNByyw Under 3k, if i jumped on it, it would bog and die or bog and take off depending on where i was at in revs. Clogged main jets (doesnt work like a nikki, but main jets are still main jets) was my issue, after the rebuild I've had no issues
Also the reason its fine with the choke probably has something to do with the way it operates. When the plate closes (choke applied) its cutting off air flow, making the car run richer. Since its running richer to begin with, the demand for fuel when you jump on it isnt as big, so no bog.
Last edited by FunK73; 11-17-11 at 09:03 PM.
11-17-11, 09:58 PM
#48
I'm standing pat on my original diagnosis.
If you get it bast the 2k hurdle, can you rev freely above? If yes, it's not the main jets.
Here's the only two pics I have that might help... but I don't have a write-up for removal. Done it so many times I just do it, you know?
Any rate, this is what an SA looks like with just the carb off: Kind of where you're trying to get to.
The thick black hose center left in the second pic is the altitude comp connection I was mentioning earlier. You have to sort of slide it up as the carb comes up off the base. I don't think you have one, though, on an 83. In 81, they moved to a kind of canister looking thing to the right of the choke themohousing.
If you get it bast the 2k hurdle, can you rev freely above? If yes, it's not the main jets.
Here's the only two pics I have that might help... but I don't have a write-up for removal. Done it so many times I just do it, you know?
Any rate, this is what an SA looks like with just the carb off: Kind of where you're trying to get to.
The thick black hose center left in the second pic is the altitude comp connection I was mentioning earlier. You have to sort of slide it up as the carb comes up off the base. I don't think you have one, though, on an 83. In 81, they moved to a kind of canister looking thing to the right of the choke themohousing.
11-17-11, 10:55 PM
#49
Oil Leak
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When do you want me to swing by and give you my nikki? I'll help you put it on and see if it does any good. But its gonna have to be soon. Snows on the way.
by the way, this is VERY similar to what my dellorto did before i rebuilt it. http://www.youtube.com/watch?v=lpkn7QNByyw Under 3k, if i jumped on it, it would bog and die or bog and take off depending on where i was at in revs. Clogged main jets (doesnt work like a nikki, but main jets are still main jets) was my issue, after the rebuild I've had no issues
Also the reason its fine with the choke probably has something to do with the way it operates. When the plate closes (choke applied) its cutting off air flow, making the car run richer. Since its running richer to begin with, the demand for fuel when you jump on it isnt as big, so no bog.
by the way, this is VERY similar to what my dellorto did before i rebuilt it. http://www.youtube.com/watch?v=lpkn7QNByyw Under 3k, if i jumped on it, it would bog and die or bog and take off depending on where i was at in revs. Clogged main jets (doesnt work like a nikki, but main jets are still main jets) was my issue, after the rebuild I've had no issues
Also the reason its fine with the choke probably has something to do with the way it operates. When the plate closes (choke applied) its cutting off air flow, making the car run richer. Since its running richer to begin with, the demand for fuel when you jump on it isnt as big, so no bog.
