radman
R.I.P. Our Motorcycling Friend
Some may recall I sent my injectors, as well as another set of 4 I had acquired, to be cleaned and matched. This was done for free, as long as they got to keep 4 so as to begin an exchange program for the FJR, something they do for many FI bikes. Got them back (this was winter teardown) in just a few days, cleaned and matched to within 1% of each other. With the valves adjusted, fresh plugs etc I figgered Frank was set for the year, and should run bonkers to boot. I was partially correct. Frank ran great, power outstanding, but mileage wasn't so great (avg 35) and he had developed a vibration in the upper ranges (4500 rpm and up). Nothing radical, mind you, just irritating, and something that has been a problem off and on since new. I feel a 4 cylinder with 2 balance shafts, an excellent state of tune, and good cylinder balance should be smooth as glass. Frank wasn't. A TBS cleaned up some of it (hadn't done one after all the work, which included the recall TPS), but he still didn't seem quite right. I did some hard thinking on the subject, because thats pretty much all I do is think motors, ask the wife, drives her nuts, which is ok by me. Then it hit me-I had 4 matched within 1% injectors! Sunday I re-barbed Frank, and dialed in a 0 CO on all holes. Voila! Smooth as silk-subsequent adjustments up brought the vibes back, less than 0 and he began to show lean effect-throttle respose slowed, light surging developed at steady mid-range speed (I have a PCIII with the Holeshot Header map and the Accel Pmp, set lightly). But at 0, Frank is smoother than he's ever been-4000 rpm there is no motor, just this electric hum. 4500 ditto. 5000 ditto. Slight, very slight vibes 6k-8.5k. I plan to try leaning the map a touch to address those, a custom dyno map would probably be my best bet-when I can afford it, I will. But 2 things became obvious:
1) Overly rich settings most definitely can cause vibration issues, and
2) One sure way to smooth a troublesome bike is to have a matched set of injectors and eliminate Yams offset adjustment.
The co adjustment in the ECM has always bothered me-as the bike ages, the injectors are gonna change slightly in output, and therefore the co adjustments intial setting requirement is gonna change also. Keeping the system clean will help to prevent this, but my system was as well as if not better maintained than any out there-and my injectors varied by 5% across the original 4. This in 2 1/2 years and 27000 miles. Without access to a 4-5 gas analyzer, and 4 ports drilled into the downpipes of the header (the way the original Wally Smoothness Map was done for the PCIII by the way), theres no way to be sure of whether the settings have changed, need to be changed, or are right on (damn doubtful, you ask me). We all know some bikes are glass smooth right off the floor, while some have nagging vibration issues that are ongoing despite bar changes, grip changes, TBS's up the ying-yang etc. This may help to finally rid those problem bikes- which I now realise Frank was one of- of those bastardly vibes.
Original Co
1) -2
2) +14
3) +24
4) +18
Injector cleaning and matching
1) Overly rich settings most definitely can cause vibration issues, and
2) One sure way to smooth a troublesome bike is to have a matched set of injectors and eliminate Yams offset adjustment.
The co adjustment in the ECM has always bothered me-as the bike ages, the injectors are gonna change slightly in output, and therefore the co adjustments intial setting requirement is gonna change also. Keeping the system clean will help to prevent this, but my system was as well as if not better maintained than any out there-and my injectors varied by 5% across the original 4. This in 2 1/2 years and 27000 miles. Without access to a 4-5 gas analyzer, and 4 ports drilled into the downpipes of the header (the way the original Wally Smoothness Map was done for the PCIII by the way), theres no way to be sure of whether the settings have changed, need to be changed, or are right on (damn doubtful, you ask me). We all know some bikes are glass smooth right off the floor, while some have nagging vibration issues that are ongoing despite bar changes, grip changes, TBS's up the ying-yang etc. This may help to finally rid those problem bikes- which I now realise Frank was one of- of those bastardly vibes.
Original Co
1) -2
2) +14
3) +24
4) +18
Injector cleaning and matching
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