On Sunday,\u00a0I rode the fuel-injected NC30 for the first time! It’s great to finally be at this point.<\/p>\n
Before I got to that point, there were a few final issues. After putting together, hooking up the fuel system, and verifying that all the sensors worked, I noticed that the throttle position sensor reported “20%” open with the throttle closed. I thought that seemed weird, since it should have been pretty well calibrated before, but I recalibrated it and moved on…<\/p>\n
After filling the fuel tank, I was pleased to note air bubbles coming out of the tank connection, indicating that the air was making it out of the fuel pump housing, and when I ran the fuel pump it only took a few second for it to prime and start pumping fuel around. Glad that worked out.<\/p>\n
When I cranked the bike it didn’t take many seconds for it to fire and the immediately rev up to the rev limiter (which I set to 8000 RPM for a cold engine). What the …?<\/p>\n
Remember that 20% throttle? Turns out that the throttle cable end for the carbs is too wide for the GPz throttle body, and was wide enough to catch on a bolt so the throttles weren’t actually closing to less than… 20%!<\/p>\n
Ok, whatever, I had hoped to not need to put a new end on the throttle cable but since it was also really too long for the adjustment to be able to take it all up, I cut an inch off the end and soldered a properly sized end on the cable. (I had planned for this and ordered a few cable ends of the right size before.)<\/p>\n
With that fixed (and the throttle position sensor recalibrated again) I figured I would do what I really should have done in the first place and log the manifold pressure while cranking. This is the real test of how well the throttles are synchronized. When I did this, I was disappointed to note quite large discrepancies. I had hoped not to have to attempt to adjust the linkage on the bike since getting to the adjustment screws would be almost impossible, but no such luck.<\/p>\n
While it requires some contorted fingers, it turns out to not be too bad\u00a0to do this adjustment (probably actually easier than with the carbs<\/a>) and after a while\u00a0it looked pretty good, the cranking MAP is about 66kPa and there’s about 1kPa difference between them.<\/p>\n After putting the bike together again I was rewarded with a pretty nice idle. I put the seat and fairing back on and took it for a spin on our street. It at least pulled well enough that it\u00a0was rideable below maybe 5000 RPM, so I went out on the super-wide road we have nearby and tested it.<\/p>\n It ran, but certainly did not run well. It didn’t want to rev past about 5000 because of lean misfires, and the front and back cylinder pairs registered quite different air\/fuel ratios, by 10-20%. But from now on, it’s all about tuning. No more fabrication necessary!<\/p>\n (Sorry, no pics or movies, I will attempt to make a recording later.)<\/p>\n","protected":false},"excerpt":{"rendered":" On Sunday,\u00a0I rode the fuel-injected NC30 for the first time! It’s great to finally be at this point. Before I got to that point, there were a few final issues. After putting together, hooking up the fuel system, and verifying that all the sensors worked, I noticed that the throttle position sensor reported “20%” open …<\/p>\n