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Beta Evo Not Crisp

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Hi I have a 2009 beta Evo 250cc, and find that it runs a bit choked, not crisp.

My old beta rev 3 ran a bit choked for about 5 mins or so, then rode Ok.

The evo feels like it needs a clear out to run smooth, it doesn

Hi, How long have you had the bike, and has it always run like this? If it has suddenly worsened - have you changed anything? If so - what was it?

If not then I would try the following (apologies if you have already tried some or all of these..) Clean the air filter and re-oil. Try again. If the same, strip and clean the carb. Use carb cleaner, remove the jets and give a good blow out with an air line. Take note of the jet numbers whilst you are in there.

Reassemble and try again - also note the needle position whilst you have it all apart. If things are no better check your jet sizes - I dont have mine to hand but they are on here in various posts - or better still ring Lampkins for advice. They will send you out their recommended sizes and are very helpful.

Sound advice from Enrico - You may have a plugged pilot jet - the stock pilot is 48 - air-screw should be about 1.1/2 turns out

depending on altitude.

  • Author

Hi, i got the evo second hand, it had only had around 5 hrs use from new. I renewed the spak plug and cleaned the air filter when i got it.

I have used it 3 times since I got it and on Sunday it was worse than the time before. It gets more choked each time its used.

I think the carb needs a clean but was unsure if was a hard job to strip.

I stripped my rev 3 carb no problem, but this carb is unkown territory for me ?

I'm running shell optimax and castrol tts oil at 66:1 ?

One thing I do hear when opening the throttle is the induction noise in the air box, is this a evo characteristic ?

Cheers for replies ....

I believe the 2009 evos were jetted wrongly as supplied is yours standard?

Are you sure, lampkin supplied " the proper" jets in 2008 when they first changed to the kehin carb, I made no changes to my '09 , it is possible that someone may have changed them though?

Once the bike is run in the needle needs changing one clip to lean it off.

  • Author
Once the bike is run in the needle needs changing one clip to lean it off.

Hi, do you move the clip one notch up the needle or one notch down ?? Cheers.

Hi, do you move the clip one notch up the needle or one notch down ?? Cheers.

Up one notch, drop the needle down.

Are you sure, lampkin supplied " the proper" jets in 2008 when they first changed to the kehin carb, I made no changes to my '09 , it is possible that someone may have changed them though?

i know mine needed one jet different on the pilot.

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