Triumphrat

earl · 08-12-2006

i'm sure if i dug around i'd find the answer but i need a few more posts to shake the newbie label. why on hot days does my bike give me some back talk after i shut it off? it is not so much POW as it is FFFUT. it doesn't happen too often, but it seems to happen on hot days after driving in town and the engine temp is on the high side. normal? or should i get it looked at? (i know almost as much about engines as i do about girls.) also, one of my headers is blueing a little more than the other. does that mean one side runs hotter and could that have anything to do with the back firing?

trypcil · 08-15-2006

The blueing indicates a leanness, hence heat. Perhaps when you come to a stop and idle a moment before you turn off a state of mild richness maybe occurring thru' the idle circuit in the carbs - the heat of the headers then when no ignition is present cause the excess vapours to go bang - the backfire. The heat of the day will affect the state of tune in some manner and form - cold dense air is what the bike wants and if it doesn't get it - well you know what happens. It could be a very simple fix like clean/replace airfilter or some simple rejetting ie mains by going up a size or perhaps a needle clip drop. Replacing the mains will affect to some extent the needle circuits as they are screwed onto the bottom of the emulsion tubes essentially - this maybe be your cure along with a airbox service. Typically EPA standards create bikes that are somewhat lean in their jetting or at least in the realm of about 5000rpm which is an area they test but again epa standards require about 1.5% of CO at idle - since all the circuits crossover one another in transition things can get complicated - but if you care to perform any changes yourself, which is easy - remember the golden rule of tuning - do 'one' change at a time, ride & assess before doing another change, keeps notes. :razz:

j98sprint · 08-15-2006

Turn the mixture screws out (from lightly seated) 2.5 turns.

j98sprint

trypcil · 08-15-2006

Great place to start. :razz:

earl · 08-15-2006

thanks for the info. i'll have to get my dad to translate it into laypersons vernacular. i've read on other posts that the bluing is because the headers are single wall and that it cannot be avoided. i also read that the AI super heats the outgoing exhaust which causes the pipes to blue, hence that AI removal kit. some people claim that removing the AI to improves performance. lots of info is out there and it's not all consistent. i've left the AI in place figuring that it has been factory tuned to run best as is, but your take on that would helpful as you sound like you know a bit about this stuff.

LT · 08-16-2006

Before I removed AI, every time I shut it off, I'd get a little "whump", first one side, then the other. Quit when I removed AI. All that system does is provide combustion air for unspent gasses so they will burn in pipes before exiting and send our planet hurtling into the Sun. doesn't affect performance one way or the other. Can be a source of vacuum leaks or other problems if malfunctions.

[ This message was edited by: LT on 2006-08-16 15:06 ]