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Carby problems

Discussion in 'Technical and Troubleshooting Torque' at netrider.net.au started by thecptn, Nov 9, 2008.

  1. Recently got a Yamaha sr250 85 model to do general mule duties, work, shops, and what not, motor had its head recoed by its PO, took it home, did the usual, oil, filters, air filter, plug, hell even chucked in a new intake manifold as the old one was cracked, but this problem still remains, after riding the bike for about 20 minutes, when coming to a stop, the revs remain very high, and take a bit of time to fall back to normal, and when taking of from light it will hesitate, almost lag, another problem is after turning it off from a long ride, it will take quite a few cranks and a lot of throttling to get it started, all these issue are absent when engine is under full normal operating temps.

    So I pulled the carb off the other day, took it apart a bit, the diaphragm looks good, no crack, every thing looks clean inside, gave the insides a bit of squirt of carb cleaner, it seemed to help it a bit, but I didn't ride it for too long so I cant say so far if it fixed it, any one have any idea what it could be?
  2. sounds like mixture to me. Have you had a look at the plugs after the ride. Are they black?

    Adjusting the mixture may not be the solution however. Look for reasons why the mixture is wrong.
  3. Yes they are a bit black here and there, running rich? it does have a rather rich smell of fuel when running.
  4. Check the valve clearances.