Messing with my Aprilia Cup

Yep, NJMP Riders Club.

 

NJMP Thunderbolt yesterday. Perfect weather and it didn't blow up again.

One minor issue in my 4th session. It suddenly seemed way down on power. 'Down on power' on that bike and my mind instantly goes to 'seizes and launches me into space' so I pulled right in. It didn't want to idle and I was assuming the worst. So I had lunch.

After lunch I got a consult from reformed 2 smoke guy Ed. We fired it up and it sounded healthy. Obviously running on both cylinders. That's when we noticed the tach was below 1 at idle (which is about 1500). Long story short, the tach had shifted counter clockwise several thousand rpm. 'Down on power' was actually running off the far side of the power band. I ran two more sessions and it got worse each time. Here's what it looks like with power off now:


I can't remember if there was a pin on the tach face that might have fallen off. Last event of the season for the RS so I have plenty of time to figure it out.

Took a second off my fast time on the bike. A couple low 37s. Lots of 38s when I was free of traffic (it's a real mystery how some of these guys got into the advanced group). Still not riding it particularly hard. I had a couple reports that it smelled good from people behind me.

 

So, are you saying it was just the tach that was messed up, not the engine? How did the engine feel? If you weren't looking at the tach, would you have thought there was an issue?

If the engine felt fine, I'd look at the tach and see if the stepper motor has come loose in the tach housing. (assuming the whole needle "range" shifted counter-clockwise). Not sure how that could happen, but who knows. If that is where it is supposed to be, you've got some gremlins to find/take care of. It's also possible the needle itself came loose, or rotated on the stepper motor, and just needs to be reset.

 

Looks like it went higher than eleven.

 

Yes, exactly, just the tach. Traffic had me slow at my normal shift point. I don't normally look at the tach but I did since I was off speed. The engine went flat at 10k or so and my mind jumped to bad things. The ECU pulls timing at 11 or 11.5 (I cant recall) before a hard limit so it wasn't banging off a limiter. The tach has a programmable warning light that probably would have triggered but I had it set too high.

The whole event was a handful of seconds. Glanced down - 10k, engine not pulling, assume the worst, roll out of it.

 

Drained the trans oil out this morning. I ran 10W40 ZMax synthetic because I had a lot of it lying around (a relative works for them). About 3.5 track hours on the oil plus a bunch of dyno pulls. A lot more metal on the plug than I expected (some actual bits, though it's hard to tell in the pic) and the oil was black. As draining neared the end, you can see lots of shiny bits in there too.





So that's concerning. I guess the transmission needs to come out for an inspection but I think I will push it into the corner and work on one of my Ducatis instead...

 

Was it a fresh assembly? Possibly it didn't get cleaned up correctly, or the cases had some contamination from a previous incident? I would change the oil and run it a bit and go through the gears, if you don't plan to do another track day? Then drain it again and see what you have? In theory that could be contaminants left over in the cases, or the clutch disks could have had a bunch of old contamination? I would be surprised new bearings or transmission gears would have anything like that coming off it.

 

Looks like the first oil change from my RS660. First new bike I've ever owned so I figured that's what it looks like when breaking in a fresh engine. The second one at 3700 miles looked beautiful. :shrug:

 

Was there a new clutch in the engine?

 

Good questions.

This gearbox was in the running engine that came with the Cup bike. It was not previously blown up. I just pulled it, looked it over, and reinstalled. I thought I cleaned things pretty well but I did not go nuts on the cassette.

Clutch was not new but, IIRC, I pulled the basket from the blown up motor. I would have cleaned it though.

I will probably pull it out and have a look. I have 6 months to mess with it and gears have been known to go boom in these engines. No reason to risk it. Maybe I'll fill it and run it around at the airport first.