Carb "cough" on idle stop .

[Tjokk]

Hi all , I am trying to bring an "old" NX650 1989 back to life. So far so good . It starts now , runs great etc. But.......when idling suddenly decides to give a "cough" through the carby and stops .
What could be the prob on this one ?? Cheers Jaap.

[KirriePete]

Sounds like the good old 'traffic light stall' - they all do that, sir. Check the inlet rubber between the carb and the head hasn't perished/cracked, it's got a weak spot on the underside. You could also try running some cleaner through the carb, I pumped some neat Redex through mine, seemed to make a slight difference (the neighbours weren't impressed by the smoke cloud produced, though!). Dunno what the Oz equivalent of Redex is, Vegemite maybe ? The simplest workaround is to raise the tickover a bit - since I set Miss Whiplash to bang away at 1600rpm or so I haven't had a single 'moment' at the lights, so it works, but you do lose that big single 'thud, thud, thud' tickover beat.

As usual, IKBA applies, more knowledgeable bodies will no doubt come along soon and sort the good info from the bolleaux for you.

You're welcome

[default]

Check and adjust the idle mixture screw. If that does not solve the problem and you are sure everything else is correct increase the idle jet up to the next size. It is just the mixture is a little weak on tickover, more of a problem in the cold weather.

Steve

[Tjokk]

Thanks KP and am , I will try it all out .!! Cold weather not really the prob here .: 30 degrees .
Cheers Jaap.

[shuriken]

If it is the carb inlet tube being cracked (have you seen the rubber pulse on tick over!? ) and you have to wait for a replacement then just make a small strip of tin foil fold it over a few times to make it thick and then secure to the underside of the tube with two cable ties. Did a good passable job for me for a week. Seals off the crack and makes the vacuum again.

[Tjokk]

Tha shuriken , as I understand it : no pulse ----cracked??
cheers jaap

[shuriken]

Not sure about that, just know that when that intake is in new condition you can see it pulse. Mine was so bad that I had to turn the tick over up to 3k! The bike was ok to ride as long as the revs were high. Try "sealing" the tube and see if it makes a difference, it's easier than taking the inlet tube out!!

[Cyrus]

Same probl on my dommie.. I have now cleaned the carb an d airfilter. And the probl is still her now and then. But its better now.

Try follow this steps in this url http://www.eikholt.net/hpalt/downloa...l%20system.pdf

This is the fuelsystem worksheet.

Tip to check out leaks in rubber, front of the carb... Spray some startgas around the rubber and there u suspect the leaks could be. If the RPM increases you got a leak.....

Keep on the good work..

Cyrus