Ohh man, ok went to Rick Stetson the dyno master yesterday. Fun day, a little long with some weird issues, but still fun.
As I expected my jetting was close. We only went down on the mains from 105 to 100. Also tried some main air jet stuff but ended up going back to the existing 220’s. He adjusted the mixture screws and it idles much better than before. I had it all too rich, and I knew it. I just wanted to be sure I was safe until we put it on the dyno.
So first thing was the clutch was slipping, AGAIN. Last time I was there we had to remove the clutch, mill the basket to accept larger heavier springs he had in stock and that helped. This time it was slipping again from 9,000 rpm and it was still trying to make power. We removed the clutch cover and put in even heavier springs than before. Put it all together and it was slipping less but still slipping. So we took it off again, broke for lunch (Harry’s Diner, really nice place with even nicer people) and then put in even HEAVIER springs and also glass bead blasted the plates. Clutch lever is a little heavier but I don’t think it’ll be a problem. Worst case I still have the other springs I can put in...or think about a hydraulic conversion...hopefully not. Back on the dyno and it pulled almost to 10,000 rpm with good power. Rick chalked the slipping up to design rather than oil (conventional) or clutch being worn out. So Don, you might want to be aware of this.
Next thing was IGNITION. The clutch wasn’t slipping anymore. But almost always we’d get a weird blip at the high end rpm. Rick almost thought the C5 had a rev limiter, that’s how it was acting. I told him about the reduced voltage deal that Paul at C5 recommended. Showed him my dc converter and he was dubious. We ended up bypassing the converter for the coils only, not the plate, and the weird blip disappeared. Next was the ignition timing. We tried 2° advanced and power dropped off. Tried 2° retarded and power increased. Then 4°, more power. 5.5°, little more power then we ran out of adjustment room. Not sure how much it would have gone but that’s how the cookie crumbles. I’m not comfortable enough to do more tests without the dyno so I’m leaving it. The C5 isn’t very precise when setting timing anyway. You put the engine to #1 TDC and then rotate the plate until the red LED comes on. But the thing is is that the red LED can stay on for like 6° of rotation. And there aren’t any marks to use a strobe. I’ll have to use my degree wheel to see where it is exactly. We also tried the different ignition curves that the C5 is programmed for. Nothing made an improvement so we kept with the #1 map where both wires are grounded (if you have a C5 you’ll understand this).
Lastly was the air/fuel map. Forever I was getting this weird spike and then dip before leveling out to a perfect ratio. We looked at other guys who had the same Megacycle 126-20 and they all had the same spike and dip. Some more pronounced than others. Mine was one of the extreme ones. Rick felt this was going to be almost impossible to tune out. He mentioned the words “fuel injection” and I put my fingers in my ears. Now, the bike feels great, my butt says the a/f ratio is a flat curve but the machines say otherwise. So it’s not noticeable from me but it’s there. I’m not worried about it.
I’m undecided if I’ll keep with the converter or remove it. I don’t see myself really utilizing 9,500 rpm that much so for now I’m going to keep it hooked up. If it starts to bug me I’ll take it off. The new Rick’s reg/rec I got which is designed for LiFe PO batteries does keep the voltage at a stable 13.8 volts. So still under what Paul wants us about. So if I remove it I’d be surprised if the coils give problems again.
All in all I love going up there. Rick is a legend with an awesome shop and Skippy the dog is the best.
Long post. Time to ride.
