more Carb help
04-05-08, 01:04 PM
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more Carb help
my carburator isnt getting any gas to it.. my fuel pump works, and gets the needed gas to the carb... the jets dont put any gas out at all.. kind of lost on where to go next.. any help would be great thanks.
04-05-08, 07:32 PM
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If it is the stock Nikki, you can buy a rebuild kit for a reasonable price. Most of them are pretty comprehensive and will replace most of the trouble spots those carbs can encounter. I bought a kit myself, and despite having very little carburetor experience, found it pretty easy to tear the carb down and rebuild. The kit came with new jets too. 
Good luck.
Good luck.
Last edited by Bradpabst; 04-05-08 at 07:33 PM. Reason: Spelling error.
04-05-08, 08:09 PM
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If your carb isn't getting any gas then the problem is somewhere in the fuel feed. If the carb is getting gas but the engine isn't then you have a different problem.
I suggest cleaning up the fuel feed system first and make sure your sight windows show gas about halfway up , then make sure the accelerator pump visibly delivers gas to the carb throat. If those things are true and the car still won't fire and run you have an ignition problem (or compression). A motor will fire and run if it's getting gas just by pumping the gas pedal furiously, even if the jets, etc., of the carb aren't working.
An unnecessary carb overhaul can create more problems than it solves.
I suggest cleaning up the fuel feed system first and make sure your sight windows show gas about halfway up , then make sure the accelerator pump visibly delivers gas to the carb throat. If those things are true and the car still won't fire and run you have an ignition problem (or compression). A motor will fire and run if it's getting gas just by pumping the gas pedal furiously, even if the jets, etc., of the carb aren't working.
An unnecessary carb overhaul can create more problems than it solves.
04-05-08, 08:18 PM
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If your carb isn't getting any gas then the problem is somewhere in the fuel feed. If the carb is getting gas but the engine isn't then you have a different problem.
I suggest cleaning up the fuel feed system first and make sure your sight windows show gas about halfway up , then make sure the accelerator pump visibly delivers gas to the carb throat. If those things are true and the car still won't fire and run you have an ignition problem (or compression). A motor will fire and run if it's getting gas just by pumping the gas pedal furiously, even if the jets, etc., of the carb aren't working.
An unnecessary carb overhaul can create more problems than it solves.
I suggest cleaning up the fuel feed system first and make sure your sight windows show gas about halfway up , then make sure the accelerator pump visibly delivers gas to the carb throat. If those things are true and the car still won't fire and run you have an ignition problem (or compression). A motor will fire and run if it's getting gas just by pumping the gas pedal furiously, even if the jets, etc., of the carb aren't working.
An unnecessary carb overhaul can create more problems than it solves.
04-06-08, 09:24 AM
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the gas makes it to the sight window.. and its about half way up... it doesnt make it in to the rest of the carb though.. the car will start if i put gas directly in the top of the carb...
04-06-08, 09:47 AM
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If the fuel bowls are full, but no gas going into carb, I believe that pretty much narrows it down to clogged jets. But if the jets are all clogged that badly, you might as well go for the rebuild.
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04-06-08, 05:59 PM
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well the jets let gas in.. but its only when it wants to.. there is gas in the sight windows half way up or so... struggling on what to do any more help plz... what i dont get is the jets let gas out earlier.. we started it, and it stopped getting gas in the carb and died now i cant even get the jets to go again...
04-07-08, 09:21 AM
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How to remove the jets without disassembling the carb (be sure to read entire thread):
https://www.rx7club.com/showthread.p...jets+toothpick
Might be a usable shortcut for you...
https://www.rx7club.com/showthread.p...jets+toothpick
Might be a usable shortcut for you...
04-07-08, 09:56 AM
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but its not my jets.. least i dont think... i cleaned them already... also the check valve or what ever on the side of the air horn, when i connect a tube and blow all four jets let gas out...
Last edited by Zake17; 04-07-08 at 10:16 AM.
04-07-08, 03:13 PM
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well i was out there again.. recleaned all four jets... still the same thing... is there supposed to be a vacuum or somethin pulling gas out of the jets or is it just pressure???
04-07-08, 03:15 PM
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It is the suction from the venturis that draws the fuel out. If there is fuel in the bowls, but it won't flow through the jets into the barrels, then I don't know what else it would be other than clogged jets... Need Sterling to stop by...
04-07-08, 04:46 PM
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It's too bad when the fuel system gets to this point of decrepitude. Such problems can be avoided by using a fuel additive, such as MMO, or any number of other products, like Techron, etc., to clean out water and avoid varnish buildup in the works.
The only carb parts I've ever seen get actually wornout and require replacement are the throttle shaft bushings. Don't know if that's true with RX-7s or not since I've only got 130k on my 83. But since the MMO is also a decent lubricant it may have postponed the day my throttle shaft bushings start leaking and wobbling.
But lots of people have problems after a carb rebuild. Petrol (gas) is a nasty fluid that will leak through microscopic leaks that nothing else goes through, and I suspect that leaks develop after carb re-assembly by DIY amateurs. Maybe that's why some people sink their floats.
The worst petrol leaks I've ever had were with piping joints. Compression joints almost always leak, and usually I had to use double-flare joints to assure integrity (on racing cars). And they have to be made almost perfectly. Barb joints to neoprene hose have to be clamped with special "FI" or aircraft hose clamps that have a full turn of plain metal (without serrations) around the hose.
Gaskets have to be installed carefully after carefully preparing the metal mating surfaces. Gasket sealers are usually futile.
Screwin jets have to be carefully prepared and tightened with the proper torque.
FI stuff is even more finicky than carbs because the tolerances are tighter.
The only carb parts I've ever seen get actually wornout and require replacement are the throttle shaft bushings. Don't know if that's true with RX-7s or not since I've only got 130k on my 83. But since the MMO is also a decent lubricant it may have postponed the day my throttle shaft bushings start leaking and wobbling.
But lots of people have problems after a carb rebuild. Petrol (gas) is a nasty fluid that will leak through microscopic leaks that nothing else goes through, and I suspect that leaks develop after carb re-assembly by DIY amateurs. Maybe that's why some people sink their floats.
The worst petrol leaks I've ever had were with piping joints. Compression joints almost always leak, and usually I had to use double-flare joints to assure integrity (on racing cars). And they have to be made almost perfectly. Barb joints to neoprene hose have to be clamped with special "FI" or aircraft hose clamps that have a full turn of plain metal (without serrations) around the hose.
Gaskets have to be installed carefully after carefully preparing the metal mating surfaces. Gasket sealers are usually futile.
Screwin jets have to be carefully prepared and tightened with the proper torque.
FI stuff is even more finicky than carbs because the tolerances are tighter.
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