Still Juddering - can you help?

Hi, just changed plugs and cleaned carbs. Hoever, she still wont pull off in 1st until I REALLY open the throttle then ok from then on. Really bad as she nearly stalled in the middle of the road yesterday! Any ideas??? thanks, Tony...

. what rpm are we talking about? try adjusting your idle mixture

Really low revs - literally from 0 to about 2/2.5... Is adle adjustment tricky? I am sure I saw a thread here describing how to use Factory Codes and grounding a wire etc... Tony...

no 4 cylinder sportbike is going to run well under 2500rpm. if you have carbs, it is tricky to get the idle mixture just right. it may be worth the money to take it to the shop. another good ides is to get a book or a shop manual for your bike and get a good ides of how your carbs actually work before you go turning screws. the carbs are actually pretty simple, and once you have them figured out it will be a million times easier. if a had a factory manual for your bike i could tell you more, but since all carbs are a little bit different, you have to do the research.

Really low revs - literally from 0 to about 2/2.5... Is adle adjustment tricky? I am sure I saw a thread here describing how to use Factory Codes and grounding a wire etc... Tony... Unfortunately that only works on the much newer models. Adjusting the tickover is done by turning one knob located above front sprocket cover. It only becomes more complicated if you have to setup the Pilot air jet screws individually on each carb to achieve a stalbe (as possible) tickover. The factory manual should tell you the number of turns out to set these screws at. On mine I think its 2.5 turns but may be different for USA models. I am assuming that the pilot jets (petrol) in the float chamber are clear/clean and the float level needle valves are working with the floats set to the right height.

Ah, I'd best do that first then! :dundun:

Ah, I'd best do that first then! :dundun: If you have had the bike a while and it was previously running fine, I would think it unlikely that the float heights are wrong as they don't change on their own.

It is possible that one of your cylinders has lost compression. I had a similar problem on my 400, where I had to give it some extra rpm to pull away, but once running it was fine. Turned out to be a carboned up valve. Just check if any of your exhaust headers are running cold after idling for a few seconds from a cold engine. That will tell you if any cylinder is not firing and which one.

exup valve.

Like the previous posters said, make sure your pilot jets are clean and EXUP is adjusted correctly. Once those are done, check carb balance and adjust idle. My favorite is Morgan Carbtune: http://www.carbtune.com Mine took less than one week to arrive. Idle knob is a brass colored knob located on the left side of the bike. Mark 99 R1