Hey everyone! I have a TTR250 Raid from 1996 which i bought about a year ago. The last couple of months, after some changes i made, i have noticed that the motorcycle behaves a bit odd. It feels like it hits unusually high revs at 1/4 of throttle and when i open it 1/2 or more the engine feels like working really really hard. Also at 1/2 throttle or more, it feels like it hits "rev limiter" and that it skips some combustions. The output of the motorcycle is not very good, it doesn't feel like it can accelerate fast and the top speed i get is max 110kmh. Also, fuel consumption is not good, i think it is more than 5l/100.
The changes i made, as i stated earlier, were piston rings, valves change, valves lapping, new shims and carb clean. I think the carb clean was the last think i did before starting feeling the bike like that.
I also want to mention that the clutch is not slipping, the manifold intake is not leaking and that my compression when hot is around 175psi, which is in spec.
Currently i have 2 things that my be the cause but i am not sure. The first one is that when i adjusted the valves, i chose the clearances to be on the (very)tight side but in spec and that may be a problem(?). The second thing is that maybe the carburetor is not working properly. I bought a cheap chinese one just to check if it changes anything but it was so chinese that it was impossible to tune .
Thats all! I really dont know what may be the cause but if anyone has any idea it would really help! Thanksss!! :)))
My first thought is that the bike is running lean. I would take the carb off and check that the jets have not blocked since the clean, and check the needle is in the correct position/not flapping about loose. Also check the carb slide is correctly attached to the linkage (the 2 tiny screws)
If the valve clearances are in spec, then they are in spec! Maybe check again to be sure.
You can check the colour of the spark plug - if it is white around the electrode = lean. Light brown = ok There are plenty of pictures on the web to compare colours.
Maybe its a lean issue. Then again my exhaust doesn't "pop" on deceleration which if i am not mistaken is a typical lean issue. I dont have too much experience on diagnosing spark plugs so i attached a photo of it with the hope that someone could help.
I also did a test with my fuel consumption test to check if it is indeed as high as i thought and it turned out to consume roughly around 5.8/100km. I only drove on the road, in moderate speed, and i only exceeded 100km/h twice. I was also riding solo without any extra weight, apart from my 80kg self.
This situation has me confused as i cant point out a what the cause may be. My rear shock is quite(super) soft and i was thinking that it may could be an issue? Still i am not completely sure. If anyone has a Raid and could share their fuel consumption it would really help, because i seem to be deviating a lot from the 3.7/100km that is annotated in the characteristics. Thanks!
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