Author Topic: Carb on Classic 500 spitting with puffs of grey smoke  (Read 4371 times)

0 Members and 1 Guest are viewing this topic.

amritc

  • Scooter
  • **
  • Posts: 41
  • Karma: 0
on: November 21, 2013, 10:43:24 pm
Hi all,

I have a question. My iron barrel has suddenly started to spit from the carburettor puffs of grey smoke when starting and then not running. Is my mix too lean?

Also, can anybody offer advice on how to replace the entire distributor unit? I am toying with the idea of doing so as my points plate is at its max on retard setting and has no more space to move the plate which means everytim the timing needs to be set the plate is taken off and the shaft needs to be pulled out

Many thanks


ace.cafe

  • Grand Gearhead
  • *****
  • Posts: 14,457
  • Karma: 1
  • World leaders in performance/racing Bullets
Reply #1 on: November 21, 2013, 11:29:22 pm
It might be too lean. Or it might have an exhaust leak or intake leak which is causing it to run lean.
Or maybe it has water in the fuel.

To refit the points deck, you loosen the Allen screw in the middle of the distributor shaft, and give the shaft a hard tap with a plastic screwdriver handle or something like that, then you can move it where you want it, and can move the points deck into a position which gives adjustment range in both directions.  Then proceed with the ignition timing process.
« Last Edit: November 21, 2013, 11:36:40 pm by ace.cafe »
Home of the Fireball 535 !


cyrusb

  • Kept man
  • Grand Gearhead
  • *****
  • Posts: 3,616
  • Karma: 2
  • There's a last time for everything
Reply #2 on: November 22, 2013, 12:11:34 am
In which direction is your plate maxed out? Clockwise or anti?
2005E Fixed and or Replaced: ignition, fenders,chainguard,wires,carb,headlight,seat,tailight,sprockets,chain,shock springs,fork springs, exhaust system, horn,shifter,clutch arm, trafficators,crankcase vent.


amritc

  • Scooter
  • **
  • Posts: 41
  • Karma: 0
Reply #3 on: November 22, 2013, 12:22:07 am
hi, it max'd out in the clockwise direction (i.e. full retarded)


cyrusb

  • Kept man
  • Grand Gearhead
  • *****
  • Posts: 3,616
  • Karma: 2
  • There's a last time for everything
Reply #4 on: November 22, 2013, 01:01:59 pm
Doesn't the dist shaft spin counter clockwise? That would make that fully advanced, no? Edit; I appears i am quite retarded also, it does spin clockwise.
« Last Edit: November 22, 2013, 10:58:46 pm by cyrusb »
2005E Fixed and or Replaced: ignition, fenders,chainguard,wires,carb,headlight,seat,tailight,sprockets,chain,shock springs,fork springs, exhaust system, horn,shifter,clutch arm, trafficators,crankcase vent.


amritc

  • Scooter
  • **
  • Posts: 41
  • Karma: 0
Reply #5 on: November 24, 2013, 08:18:15 pm
All sorted now. It was the rubber pipe at the carburettor manifold intake that had perished. It had a large tear that was not visible until I removed it. Replaced it and the bike runs sweet...

Though still unable to work out why I only get 10V output on the two violet wires coming out from the alternator....

cheers


amritc

  • Scooter
  • **
  • Posts: 41
  • Karma: 0
Reply #6 on: December 01, 2013, 08:20:32 pm
Hi, A question for all.

Will removing the cylinder head for a decoke need me to re-time my ignition? I removed the head for a decoke and in the process also moved the pistion up and down (using the kick start) to check for play. I then put the head back on. Upon starting the engine - it starts eaasily - but the beat does not settle back to the enfield thump thump sound and sounds very erratic. Also trying the mix at the carb doesnt help. Screwing air screw completely in seems to help but not really.

Do I need to re-time?

Any words of wisdom?


Arizoni

  • Grand Gearhead
  • *****
  • Posts: 7,412
  • Karma: 2
  • "But it's a dry heat here in Arizona
Reply #7 on: December 01, 2013, 09:44:28 pm
If you didn't mess with anything that controls the ignition then there should be no change.

Cranking the engine over wouldn't change things.

There is some likelihood that there is an air leak between the cylinder head and the carburetor/fuel injector.  That would cause the engine to idle at a higher speed.
Jim
2011 G5 Deluxe
1999 Miata 10th Anniversary


ace.cafe

  • Grand Gearhead
  • *****
  • Posts: 14,457
  • Karma: 1
  • World leaders in performance/racing Bullets
Reply #8 on: December 01, 2013, 10:13:48 pm
No, you need to re-jet and re-adjust your carburetor.
If you can screw your air bleed screw in all the way without the engine dying, you have the wrong pilot jet in there.What pilot jet is in there now?
Home of the Fireball 535 !


amritc

  • Scooter
  • **
  • Posts: 41
  • Karma: 0
Reply #9 on: December 01, 2013, 10:22:26 pm
Hi Ace,

My pilot jet is a 110


ace.cafe

  • Grand Gearhead
  • *****
  • Posts: 14,457
  • Karma: 1
  • World leaders in performance/racing Bullets
Reply #10 on: December 01, 2013, 10:33:20 pm
Hi Ace,

My pilot jet is a 110

110 is a main jet number.
Your pilot jet is the little one, with a number like 25.
And unless you live on top of the Himalayas, a 110 main is too lean for a main jet anyways.
Home of the Fireball 535 !


amritc

  • Scooter
  • **
  • Posts: 41
  • Karma: 0
Reply #11 on: December 01, 2013, 10:49:18 pm
Thanks Ace. I will find out the jet number and revert. But previously my main jet was a 120, the local royal enfield guy asked me to change it to a 110.

Auckland is about 150m above sealevel.


ace.cafe

  • Grand Gearhead
  • *****
  • Posts: 14,457
  • Karma: 1
  • World leaders in performance/racing Bullets
Reply #12 on: December 01, 2013, 11:29:57 pm
Well, I live about 250 meters above sea level, and my Mikarb 28mm needed a 27.5 pilot and a P2 needle jet, and a 127.5 main jet.

The bike comes stock with a 110 main jet, and a 25 pilot jet, and an O8 needle jet. The 25 pilot is sometimes okay for higher elevations, but the needle jet and the main jet are too lean for your elevation. They jet it this way because it comes from the factory all plugged-up at both ends, and also needs to pass emissions testing, so they don't put any fuel into it.
If you have a decent air filter and have dumped the crappy stock bazooka muffler, you need richer jets.

"Hunting", which is a term for an unstable idle speed which cannot seem to settle down, is a symptom of lean mixture. If you can close down the air bleed screw, and the engine doesn't die, then it's too lean in the pilot jet. This comes right from the Mikuni tuning book.
Not too sure what kind of dealer you have in Auckland, but it sounds to me like he isn't too knowledgeable.
Home of the Fireball 535 !


amritc

  • Scooter
  • **
  • Posts: 41
  • Karma: 0
Reply #13 on: December 02, 2013, 08:08:47 pm
Hi Ace,
the main jet is 110 and the pilot jet is 25
The needle jet has a marking that says 8???

what would you recommend?


ace.cafe

  • Grand Gearhead
  • *****
  • Posts: 14,457
  • Karma: 1
  • World leaders in performance/racing Bullets
Reply #14 on: December 02, 2013, 09:59:16 pm
They are all factory stock, as supplied with a new bike.

What year is the bike?
What air filter system do you have, and what exhaust/muffler system do you have?
I need to know these to answer.
I already know the elevation.
Thanks.
« Last Edit: December 02, 2013, 10:02:05 pm by ace.cafe »
Home of the Fireball 535 !