My name is Ross Mckinlay I live in Essex and have a 2004 Blue TTR. I have just joined the Forum and am after some advice!
One of the reasons i bought the TTR was so that i could learn to do all the maintenance myself as Im not that confident/experienced
I was trail riding on Sunday and the bike started running roughly in the 2nd half of the rev range from about 50mph onwards it tops out at 70.
I hasten to add that it wasnt a problem on the trails only on the roads in between!
I suspected dirt in the carb as eventually it cleared itself and for the last two hrs was running fine.
I would like to take the carb off and have a look. I have had a look at the bit on cleaning the carb on the forum which is very helpful but am unsure as too whether this is necessary now or if i do take the carb off where is the problem likely to be?
I would check your fuel for water, drain a little from the drain screw, check your air filter and check the inlet stub, before you take the carb apart. But it does sound like a blocked jet.
The fact that your TTR runs out of steam at the top of the rev range does point to a fuelling issue.
As Steve suggests, drop some fuel out by loosening the drain screw at the bottom of the carb float bowl. Be very careful when doing this that you have a really good fitting screwdriver and try and hold the carb so that you can put some pressure on the screwdriver as these suckers can be tight and have been known to round out
Try and catch what comes out to check how clean (or not) the fuel is. Also let the fuel run out for a while to check that you have a good flow of fuel from the tank as, if any of the filters are partially blocked, the fuel won't be getting into the carb fast enough to sustain higher revs.
Don't smoke or light a match whilst doing this
A less common fault that shows your symptoms is a blocked vent on the tank cap. If enough air can't get it a vacuum can be created in the tank and slow the flow of fuel.
Thanks for the replies the time before last i was a little over enthusiastic going through puddles which did cause a misfire which cut the bike out until i sprayed the plug with WD40.
This did feel different as it was in the 50 - 60mph area it would stutter its way from 50 to 60mph in top and was always worse after a bumpy track!
It did eventually clear and was running fine at the end
I will have a look for where the drain screw is on the forum before i attempt anything!
Just a side note, one of my bikes and a few other owners have a bit of a problem when going through water and we find that taking the drain pipe off the emulsifier and letting the watery oil crap out makes thing's work well. Still not sure how or why this works, but it does.