Motorcycle Repair: Start TTR-125, yamaha ttr 125, heat range

Question
I have A 2000 YAMAHA TTR-125. It is very hard to start. It seems it is the caburation. When it does start it takes a long time to warm up and run without choke. I have cleaned the carb. and made sure the choke works. any Ideas?

Answer
Hi Frank.

Does the bike sit for long periods (more than 2 or 3 weeks) between rides?  If so, then cleaning the carb will need to be a pre-ride ritual.  It only takes a few weeks for varnish to build up and it would be in the tank and the fuel lines, which would re-contaminate the carb.

If that is not the case, then there is the possibility of a loss of compression.  You may want to do a compression test and see if it is near the bottom of the compression range.

It could also be (and more likely than compression) the timing and/or valve adjustment is off a bit or the plug heat range is too cold.

Start with those and let me know what you find.

Good luck and ride safe.
FALCON