I have a 1994 Triumph Tiger that is really unwell. Problem started when the tacho started going crazy over 5000 revs - tacho was spiking all over the place. This was followed by temporary misfire at 4500 revs but has now got worse so the bike runs like a pig and wont tick over. Changed the CDI unit for one bought on ebay - no difference. Checked for good spark on all three coils - ok... and changed the plugs - still no improvement. Any ideas anyone?