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Carbs and Fuel System
From the gas tank to the carbs
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post #21 of 52 (permalink) Old 05-16-2020, 08:16 PM Thread Starter
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The slides are vibrating rapidly as in up and down motion. When i twist the throttle the slided move as they should but the carbs are spitting fuel and popping. Anywhere near 2k and it hesitates and dies. Im waiting for a new rebuild kit for the carbs but it just dont add up. I made sure they were squeeky clean before i put them on so the jets cant be blocked
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post #22 of 52 (permalink) Old 05-16-2020, 08:47 PM
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Try it with the air filters installed?

Some reversion (spitting gas back out intake side) can be normal, but an excessive amount combined with the right sort of popping, can mean a leaking intake valve.

Compression test? Air test?

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__________________________________________________ ____________
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Owner's Manual: http://www.mediafire.com/file/nscb5f...ers+Manual.pdf

Last edited by Spockster; 05-16-2020 at 08:51 PM.
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post #23 of 52 (permalink) Old 05-17-2020, 05:46 AM Thread Starter
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Quote:
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Try it with the air filters installed?

Some reversion (spitting gas back out intake side) can be normal, but an excessive amount combined with the right sort of popping, can mean a leaking intake valve.

Compression test? Air test?
comperssion is good so im thinking air myself. I was thinking about it last night and the only thing that was different with the carbs was when i was cleaning them the 2 tiny o rings that are at the base of the air/fuel mixture screw came out. Im just wondering if they somehow managed to twist a bit going back in. Slightly blockinging the air/fuel ratio
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post #24 of 52 (permalink) Old 05-17-2020, 06:52 AM
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Again, the slides move up and down in sync with the intake stroke of the cylinder that carb supplies. this is normal. more throttle will cause them to open more on each stroke.

you may have an issue with the carbs still, I am just pointing out the pulsing of the slides is normal.

if they didnt pulse, I would look at the slides, diaphrams, or other vacuum issue in the carb

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post #25 of 52 (permalink) Old 05-17-2020, 07:14 AM
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I don't think the air adjustment is going to cause all those symptoms so far above idle rpm.

By air test, I meant similar to a leakdown test, pressurizing the cylinder and see if there's any air where it shouldn't be, as with a leaking intake valve.

Won't hurt to check those o-rings, an internal air leak can only cause a problem. We could be looking at overlapping symptoms.

When does the popping occur? All the time, only above 2000 rpm, or only right before it dies? Or is it random?

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Shaved w/UniPK92+Stock Jets-TPE/MOSFET-Shinko Tires-AGM batt-bags-chrome-LEDs...more
__________________________________________________ ____________
Repair Manual: http://www.mediafire.com/file/mj7z81..._Catalogue.pdf

Owner's Manual: http://www.mediafire.com/file/nscb5f...ers+Manual.pdf

Last edited by Spockster; 05-17-2020 at 07:46 AM.
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post #26 of 52 (permalink) Old 05-17-2020, 10:41 AM Thread Starter
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Quote:
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I don't think the air adjustment is going to cause all those symptoms so far above idle rpm.

By air test, I meant similar to a leakdown test, pressurizing the cylinder and see if there's any air where it shouldn't be, as with a leaking intake valve.

Won't hurt to check those o-rings, an internal air leak can only cause a problem. We could be looking at overlapping symptoms.

When does the popping occur? All the time, only above 2000 rpm, or only right before it dies? Or is it random?
It happens all the time. I cant touch the throttle or it will bog and instantly die. Right so here is what im doing. Iv ordered a fuel tap rebuild kit, carb rebuild kit. Im putting back on the surge tank and stock air filters. Leaving the emmisions crap off. Its deffo a carb problem because after the engine rebuild it would not fire as you no and once i cleaned the carbs it started first pick only now there is the current problem. I just pulled the jet cover and on the front carb the little triangular shaped rubber gasket was broke. Still together but just sliced if you get me. Could this have caused the problem. Also thanks mishiganteddybear. I get what you mean about the slides.

Last edited by Will750; 05-17-2020 at 10:43 AM.
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post #27 of 52 (permalink) Old 05-17-2020, 12:01 PM
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Quote:
Originally Posted by Will750 View Post
Quote:
Originally Posted by Spockster View Post
I don't think the air adjustment is going to cause all those symptoms so far above idle rpm.

By air test, I meant similar to a leakdown test, pressurizing the cylinder and see if there's any air where it shouldn't be, as with a leaking intake valve.

Won't hurt to check those o-rings, an internal air leak can only cause a problem. We could be looking at overlapping symptoms.

When does the popping occur? All the time, only above 2000 rpm, or only right before it dies? Or is it random?
It happens all the time. I cant touch the throttle or it will bog and instantly die. Right so here is what im doing. Iv ordered a fuel tap rebuild kit, carb rebuild kit. Im putting back on the surge tank and stock air filters. Leaving the emmisions crap off. Its deffo a carb problem because after the engine rebuild it would not fire as you no and once i cleaned the carbs it started first pick only now there is the current problem. I just pulled the jet cover and on the front carb the little triangular shaped rubber gasket was broke. Still together but just sliced if you get me. Could this have caused the problem. Also thanks mishiganteddybear. I get what you mean about the slides.
Ok, I recall which bike this is, but often forget which member's bike has what done to it.

So it's sitting there idling and popping back through carb, then carries on and dies when you gas it more than 2000r,?

Petcock leaking doesn't help. Not sure I would put the airbox back in just yet. You haven't really cruised with the earshave yet have you?

The carb gasket probably isn't the problem but needs fixed.

If the answer to my first question is yes, I really think you're looking at a leaking intake valve and your carbs may be fine other than the gasket.

Also thinking an intake valve leaking might induce a bad pulse on the slides. I know they move, but you may have been seeing this pulse in the vacuum from the intake leak.

A vacuum gauge would show a consistent fluctuation downward every time that cylinder completes a cycle, with a leaking valve. An abnormal pulse in the vacuum. Great diagnostic tool to keep around, saves time and aggravation.

2003-21k mi
Shaved w/UniPK92+Stock Jets-TPE/MOSFET-Shinko Tires-AGM batt-bags-chrome-LEDs...more
__________________________________________________ ____________
Repair Manual: http://www.mediafire.com/file/mj7z81..._Catalogue.pdf

Owner's Manual: http://www.mediafire.com/file/nscb5f...ers+Manual.pdf
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post #28 of 52 (permalink) Old 05-17-2020, 06:01 PM Thread Starter
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Spockster thank you for all your input. Iv just ordered a gauge so should be here hopefully by the end of the week. Have some bits ordered so all will get done regardless. Just hope that i dont got to pull the engine again for a valve job. I will keep this thread posted for future references.
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post #29 of 52 (permalink) Old 05-17-2020, 06:23 PM
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You're welcome, hope I'm not sending you on a wild goose chase. The answer to that question earlier was yes, correct ?

Pulled my engine twice in two days because I goofed installing the damper gear. I really wanted that first ride.

Second time was easier, quicker.

Where did you find the gauge? Was about to remove the one from the dash of my pickup, all my toolbox gauges are too old to use.

Look up some charts online for vacuum readings, will help with troubleshooting other engines. Though I've seen one or two that didn't jibe with printed manuals. Almost all Chilton, Haynes, Clymer automotive manuals have the chart in the troubleshooting section.

One of the vac gauge's best uses is checking for valve problems ... Oh and clogged Cats too.

2003-21k mi
Shaved w/UniPK92+Stock Jets-TPE/MOSFET-Shinko Tires-AGM batt-bags-chrome-LEDs...more
__________________________________________________ ____________
Repair Manual: http://www.mediafire.com/file/mj7z81..._Catalogue.pdf

Owner's Manual: http://www.mediafire.com/file/nscb5f...ers+Manual.pdf

Last edited by Spockster; 05-17-2020 at 06:26 PM.
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post #30 of 52 (permalink) Old 05-18-2020, 05:24 AM Thread Starter
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Quote:
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You're welcome, hope I'm not sending you on a wild goose chase. The answer to that question earlier was yes, correct ?

Pulled my engine twice in two days because I goofed installing the damper gear. I really wanted that first ride.

Second time was easier, quicker.

Where did you find the gauge? Was about to remove the one from the dash of my pickup, all my toolbox gauges are too old to use.

Look up some charts online for vacuum readings, will help with troubleshooting other engines. Though I've seen one or two that didn't jibe with printed manuals. Almost all Chilton, Haynes, Clymer automotive manuals have the chart in the troubleshooting section.

One of the vac gauge's best uses is checking for valve problems ... Oh and clogged Cats too.
yes to the question earlier. Iv order one from motorcycle shop here in ireland so it should be right. I have the haynes manual so i will have a look in it for the specs. Iv pulled this engine more times than id like to say. Put it this way. 15 mins for an engine pull and 5 mins for carbs. Im sure i could take the engine apart at this stage witj my eyes closed lol. I think this time tho if it is the valves of something like that im just gonna send her to a mechanic and get it back when its ready to ride. I no it runs so thats the main thing. If it didnt run i would have just parted it out. Time will tell. Lets hope its an easy fix like something i over looked.🤞. On the other hand once i find the problem it should help anyone else that runs into this situation.
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