I have a 2008 which has been standing. I have cleaned the carb 5 times and am sure there is NO dirt left. Its completely stock with 4000km on the clock. Starts without the choke when cold which I think is a problem.. Then if I take it for a ride , it pulls hard and clean through the gears until I engage 6th , then it starts surging. Closing the trottle slightly does not help either. The bike is not running out of fuel as the float is set as per manual. When surging in 6th , I can put it back to 5th and its not there...
Have you read the TTR250 FAQ web pages link in the top left hand corner of this page?
If you haven't then your question probably has an answer there, as follows...........
"Problems with carburation after long-term storage & non-use. Geoff Denham" says: I have a 2001 TTR250 (North American version). I had cold starting and idle problems. I found out that the previous owner had stored the bike for 2 years without draining the fuel from the carb. I then discovered why he hadn't drained the carb - the Philips head of the drain screw was stripped such that no screw driver could turn it. The jets in the carb. were blocked up with residue from the evaporated fuel, and the throttle pump diaphragm had become hard (long term storage). I removed the carb. from the engine and had it overhauled by the Yamaha dealer. In most cases it maybe just gummed up jets. Check to see if you can drain the carb. If your drain screw's head is stripped, have the carb. overhauled. Removing the carb can be quite a big job if the air box is removed first. If you do this, take careful note of the connections and routing of the various rubber hoses connected to the carb. Its a good idea to thoroughly clean the inside of the hoses and their one way valves etc. You should download the Yamaha service manual, I found it very helpful. I should have added, after I had removed the carb, I also removed the rubber intake manifold and refitted it with an application of a high temperature sealing compound. All this effort was rewarded with new bike starting, idle, and general good manners. As in this case of my low mileage bike, such results assume there are no other significant engine problems. if you're having problems starting, it might be time to check your valve clearances. 25 April 2007"
Check it out.
If this doesn't answer your problem then we will have to look further. Let us know.
All fixed !!! I took out the reducer inbetween the header pipe and the silencer , down 1 size on the main ( 145 ) and removed the snorkel out the airbox.... Its going like a boeing !!
Great - pleased to know you sorted your problem satisfactorily.
Beware that removal of the snorkel precludes safe travel in deep waters. The snorkel is a safeguard when crossing deepish fords that may splash water up and under the seat area. With no snorkel the water can easily cascade into the airbox and flood the carb/engine.
In other words, "Don't go crossing the Red Sea" in the near future!
