Engine vibrations and high idle speed.

[Transalicante]

Hi guys,

I'm experiencing some troubles with my '03 TA.

A few months ago, with 37.000 kms on the clock and after driving more than half hour on a motorway the idle speed used to be 1.400 rpm, far too high.

Then, at 39.000 kms the engine started to vibrate a little bit at any rpm, and the idle speed climbed to 1.600 rpm and was irregular. Everything else was perfect: start and running when cold, no loss of power, etc.

So at 40.000 kms I replaced the spark plugs (the old ones were in perfect condition), and the air filter with a K&N (better engine response and less consumption ), I also checked the valve clearance wich was perfect and no adjustement has to be made.

But the vibrations were still there, and the high idle speed too.

This morning I checked the vacuum hoses, the choke springs and the intake rubbers. I found a little loss of fuel in the intake of the front cylinder. The four metalic collars of the two intakes had a little play, so I tightened them.
Now it's worse. I had problems starting the bike, and when hot the idle speed is around 1.000 rpm, irregular and with some misfiring. The engine sounds unbalanced.
The bike accelerate fine and no loss of power is felt.

I'm supposed to go to Morocco in a week with my TA and cannot find the fault, any suggestion would be appreciated.

Thanks a lot.

[StumpyFingers]

Have you balanced the carbs?

[Sharribee]

Have to agree with stumpy, I would get the carbs balanced

[Transalicante]

Thanks for your answers,

Now let me say that I feel really stupid, and believe me, never try to solve an administrative problem on a mobile phone while you're working on your bike.
Just checked my TA this morning and saw that yesterday I left the pilot screw fully closed on the left carb.
So now with standard setting (3 turns out) on both carbs and the idle speed adjusted to 1.200 rpm, everything is going a lot better excepted...

I still have the vibrations and irregular idle speed. The vibrations are not very important but really uncomfortable, they make your hands and feet go dumb after half hour of riding. So planning a 4.000 kms trip soon, that's something important.

The carbs balancing was my first thougt, but I had the same problem on my old NTV 650 with 60.000 kms on the clock, and after a "profesional" carbs balancing I didn't noticed any improvement. I then sold the bike with 80.000 kms and running perfectly excepted the little vibrations.

I'm probably going to balance the carbs anyway, but don't want to throw money for nothing.

If you had the same problem, and a carbs balancing solved it, please let me know.
Thanks a lot.

[tom81]

And you have checked all mounting bolts and so on ?

[Transalicante]

Yes, excepted the one connected to the swing arm. I'll check it tomorrow.

Just for information, yesterday when I left the pilot screw fully closed by mistake on the back cylinder, the vibrations increased a lot on the footpegs but not on the handlebar. Just wanted to share my vibrating experience