THEMA:

Halo aus Spanien. i werde aus English sprechen weil mein Deutsch noch nicht so gut ist haha

Well i bought an Honda Xbr 500 5 months ago. I rebuild the carb, the membrane was ok, i just change the air cut-off valve (membrane) and clean very well the jets, etc.. i changed the coil, the spark plug (check the gap, "twice") and the pipe too. I adjust also the timming valve.
But the bike in idling position it does not run well, i changed the air filter, and i check that the intake manifold had no air leaks. i check the compression of the engine and it gave 127 psi, the manual says that new was 172 so it seems quite normal for a bike that has never been rebuild. i carburated the bike as the manual says, 2,5 turns out and then play with the ralenti screw. it seems that when the bike is hot it runs even worse. The colour of the spark is black instead of brown/black.
i have to theories:
1) maybe i should do the valve seats
2) it has something to do with the carb

Does anyone had the same issue?

thank you!

wenn Sie auf deutch antworten kein problem fur mich ist! ich verstehe! haha

Inspektor the choke cable. The Plastik screw is often broken Neal the carb. On which Measurements did. you set the Valves? Use 0.15 and 0.18 instead the original Values. Check in the carb gehts air from somewhere it shouldn‘t.

Vielen Dank für Ihre Antwort,

I have noticed that the chocke cable was a little bit damaged but i did not thought it coud be the reason. I'll try the value that you gave me for the valves intake 015 and exhaust 0.18. Do you have any other recommendation to improve it? I would be interested to improve the exhaust to a 2 into 1 and maybe the carb to a Mikuni TM40.

Vielen Dank!

The sound will get worse with any than the original exhaust. But TM40 is always a good idea. You can get it perfectly configured at www.mainjet.de