so I **FINALLY** got all the parts to finish the carb rebuild on my ‘97 BMW F650 Funduro... we waited on one peice from BMW Germany for three weeks, then finally called them and asked what was up, they said the part was EOL and not stocked, and they were sorry they should have kicked back the order immediately instead of leaving it marked BO :p
In any case, we took another two weeks to find one -a stupid little last-chance fuel filter- at a dealer in North Carolina, and now everything’s ready and we soak and clean the old parts and put all the new stuff in and check the valve clearances and wrestle the fucking carbs and airbox back into the bike (if you’ve ever done this on an F650, you know what a motherfucking bitch it is), struggle to get the damn fuel tank aligned again, drain out the gassy oil from when the carbs decided to puke fuel into the engine, hook it up to the jumper cables (battery is dead, need a new one) and start it... or try to start it... and continue to try...
does it have fuel?
does it have spark?
does it have compression?
yup (it damn well better)
is the choke linkage working?
so we hit it with some starting fluid and it fires... it runs like crap... meh, blow it out! Rev it to 5000, it has no throttle response, and the headers a glowing red in under a minute...
*not my engine, but it is a Rotax, and you get the idea (also I like the picture)*
So, it’s running hellishly lean... that explains it... but WHY????
then we think back to the reason we had to replace so many parts of the carbs... some one had “serviced” them previously...
*artist’s concept of previous carb service*
frankly it was surprising the thing ran as well as it did before it stopped working all together...
The old needle valves looked like freake’n step pyramids and were not sealing any longer and that was why it was running rich and puking fuel...
so we put new seats and valves in, but you know what? I bet the individual who serviced it previously didn’t. I bet that individual compensated for the worn valves by bending the tabs on the floats and just jamming them against the seats as hard as possible... again, its kind of a miracle it ran as well as it did...
we replaced everything else, but we didn’t replace the floats. we also didn’t check the float height... because everything was new! no need! it’s just goes together! it’ll be great!
WE NEVER CHECKED THE FLOAT HEIGHT.
now we have to pull the whole goddamn thing apart again.
to fix something that would have taken 20 minutes if we had just not been idiots.