GB500 Won't always idle / 'pops and stops'

**sammcj** · 11th March 2009, 06:48

Originally Posted by DangerousBastard

Good. Does the bike still cut out when you ride it with the choke partly on?

You can see where I am going with this.. Can you get your hands on another identical carby to try?

Steve

No I don't think it does...
Yep one is going in today!

**Max Preload** · 11th March 2009, 15:41

My money is on insufficient ignition advance.

**CookMySock** · 11th March 2009, 17:32

Originally Posted by Max Preload

My money is on insufficient ignition advance.

I think it will still run if its under-advanced. It will just have no performance.

Since the choke makes a big difference, I reckon its carb related. Maybe float level is way too low.

Steve

**sammcj** · 11th March 2009, 18:46

Carb has been replaced today!

Popping and stopping went from dieing every 10secs / 1min to.... not dieing on idle, and stopping about every 5th set of lights! so I'm happy with that.

over 4,000rpm bike is fscking guttless as hell, so I'm going to finish the 1000km run in and then KG is going to reduce the jet a small amount.

**sammcj** · 11th March 2009, 18:51

I just wanted to say a BIG thank you to everyone on the forum that has helped me out with this.!

**jonbuoy** · 11th March 2009, 19:09

Good stuff mate - well I guess if its carb related its either too much or not enough juice - as DB mentioned if you can get to the choke safely whilst up at 4000+ you can crack the choke open a little - if you feel the bike pick up its too running too weak - if it bogs down more its too rich. Theres no splits or leaks in the carb to cylinder head boots??

**CookMySock** · 12th March 2009, 06:58

Originally Posted by sammcj2000

Popping and stopping went from dieing every 10secs / 1min to.... not dieing on idle, and stopping about every 5th set of lights! so I'm happy with that.

Good. Try the choke-partly-on trick again and see if that problem goes away. If it does, you are running way too lean - dont ride it! If you leave it idling for a while, does it get real hot? Does the engine revv freely when you squirt the throttle, or does it fart and miss like a cold engine, or does it sound flat and just not revv?

Do the exhaust pipes run real real hot - like nearly blueing themselves? Does someone have an infra-red temp meter you can check it with?

Originally Posted by sammcj2000

over 4,000rpm bike is fscking guttless as hell, so I'm going to finish the 1000km run in and then KG is going to reduce the jet a small amount.

I'd strongly suggest you didn't do that run-in yet. If its running way too lean you will fuck it in less than half that distance, and then it will be a smoky rattly piece of shit.. Get someone to check that exhaust gas temperature or exhaust CO.

Be careful.
Steve

**sammcj** · 12th March 2009, 09:59

tried it out on my way to work today,
turning the choke on while riding bogged it down

1/3 on - bogged it down a bit.
full on - bogged it down a lot.

i asked the mechanic at kg and he wasn't worried by it at all, he is doing to decrease the jet size to 150(?) in 500,
If i get any problems he will be the one responsable to fix it.

Oh and the engine / exhaust is running no hotter than it has done before!

**jonbuoy** · 12th March 2009, 10:08

Originally Posted by sammcj2000

tried it out on my way to work today,
turning the choke on while riding bogged it down

1/3 on - bogged it down a bit.
full on - bogged it down a lot.

i asked the mechanic at kg and he wasn't worried by it at all, he is doing to decrease the jet size to 150(?) in 500,
If i get any problems he will be the one responsable to fix it.

Oh and the engine / exhaust is running no hotter than it has done before!

Keep us posted mate sound like he was on the right track!

**CookMySock** · 12th March 2009, 14:29

Good, coz running real lean will eff it pronto. Keep us informed. Retarded timing is my guess, or blocked airfilter or something wtf stupid like that.

Sparkplug gap isn't closed up real real tight is it ?

Steve

**sammcj** · 12th March 2009, 14:31

Gap is all g.
Timing is all automatic.
KG told me when he took the air filter side off it went a lot better, but yeah wait until after the 1000km is up to see!

**CookMySock** · 12th March 2009, 15:34

Originally Posted by sammcj2000

KG told me when he took the air filter side off it went a lot better, but yeah wait until after the 1000km is up to see!

Thats a big hint it's giving you there I think. I'd do a quick air-filter-off check, and if that solves the whole problem then its new air filter time (I'd put a new air filter on a new engine anyway) or at least get to the bottom of "why it do dat."

I post again just because I reckon its unwise to do 1000km on a brand new engine with such a serious fault that hasn't been diagnosed. If we KNEW it was retarded timing (for example) then do the 1000kms coz that PROBABLY won't hurt it. But we don't know.

Anyways, good luck!

Steve

**jonbuoy** · 12th March 2009, 21:09

If it ran better without a filter could also be an indication of running rich. As long as its not chronically rich and getting petrol wash on the walls of the cylinders it probably won't do any harm in the short term. Being aircooled it might keep the temperatures down until its run in.