Will air leaking into carbs keep it from firing?

[skervey35]

Hey guys got a quick Q, my carb boots are old and cracked but look to be clean from cracks on the inside. But im having a hard time getting the bike to idle on the felt side. I know the bike will run lean if its sucking air on that side but will it keep it from running ir its sucking to much air? If i give the bike a lot of gas the left side will pick up and run, but will back fire and pop. Another issue that im running into is that the carbs are not a matching pair. One is from a newer bike so right now I am trying to find out if i will ever get the bike running good with the carbs that are on it. If it wont I may get a pair of carbs from Mikes xs (cant find any on ebay or craigslist)

Thanks for the help guys!

 

[bcware]

Yes, if a mixture is too lean it is possible that it will not fire. Replace the cracked boots regardless; they will fail eventually if they haven't already.

Right now I think it is more likely that your carbs are simply not clean or they have incorrect settings within them.

 

[1979XS4002-F]

Im guessing you need to sync them, your best bet is to bench sync them first..to do this remove the carbs from the bike set them on clean workbench and grab a nice clean 1/8" drill bit, now adjust the idle screw so the smooth(chuck) side of the drill bit just barely slides under the throttle slide..now repeat on the opposing carb...if they are different you will need to adjust with the sync screw..see carb schematic
Edit: Both carb slides must be the same height in order for them to react the same.

 

[HoughMade]

Here's the broken record...sounds like your idle circuit is still dirty and needs a good cleaning, really good cleaning. It's a broken record for a reason and the reason is that 80% of the time, this is the problem.