Unusual problem - C14 motor quit, now diagnosed and repaired.

[Jes]

Hi All.
I have a 2008 C14 with 43000km on it. On the first day of the COG Summer Solstice Ride my C14 broke down just north of Creston, BC. It died while riding and on the throttle at midrange rpm. There were no prior symptoms, it was as if I had hit the kill switch. With the help of my fellow Coggers we spent a lot of time and did all the roadside diagnostics we could think of. It would turn over and kick or pop a bit but not start. Special thanks to SISF – I called him from the side of the road and he gave us a half hour of his time trying to help figure the problem out.

A passing local biker came to the rescue. He went home and brought his truck and trailer to bring me back to Creston, where I got a one-way UHaul van to take the bike 300 miles back home to Calgary.

SISF suspected I may have broken valves, so on his advice I did a compression test. With my cheap gauge I got about 140psi across all four. I then took the valve cover and timing cover off to check the valvetrain. Some valves were a bit tight, out of spec. None were very loose. The cam chain tensioner and chain were intact and the timing marks lined up as normal, but…

The ignition rotor was missing four fingers. The crank sensor was bit banged up and the inside of the case had scratches from impact. I took the oil pan off and found all four pieces. With the oil pan, timing cover and valve cover removed I ran a magnet tool all over. I didn’t find any additional metal bits in there. I ordered a replacement ignition rotor and crank sensor.

I was planning to do a valve adjustment over the winter. Since I had to wait four weeks for the parts to arrive and the bike was taken apart, I went ahead and swapped out eight shims to get all the valves in spec. In the process I was able to confirm that both cams were ok. The VVT module was firmly attached, and the exhaust cam still had the two bolts and sprocket in place. There were no bolts or locating pins/dowels missing. I reassembled the essentials and waited for the replacement part.

A couple of weeks ago the replacement ignition rotor arrived. I installed it and my C14 started right up and ran as normal. The crank sensor is still a bit banged up, but works. My replacement hasn’t arrived yet.

I’ve put about 1000 miles on it since the repair and it’s been running as normal. I emailed pictures of the broken ignition rotor and matching bits to Boomer. He thinks it was a defective part.

So, has anyone else heard of an ignition rotor failing on its own? I can’t find anything that could have impacted it and broken it.

Cheers
Jesal

[Steve in Sunny Fla]

Very interesting. I wonder if something fell down the cam tunnel and lodged long enough to break the rotor fingers off. I've seen that happen on the c-10's.  good work finding / fixing it, too bad it had to happen so far from home. Steve

[Jes]

Hi Steve!


I bought the bike last fall, so I too thought that maybe someone who worked on it last dropped something in the top of the motor. If that's the case, I never found the offending part.


There was a small amount of some kind of sealant holding the o-ring onto the timing cover, and also near where the crank sensor wires exit the engine case. It's not as soft as Permatex, it's harder, flexible and almost clear in colour. It was loose in places, so I guess it's possible a bit of that got loose and then got pinched between the ignition rotor and sensor or another pinch point. There is not much clearance between the ignition rotor and the engine case or the bolt that holds the lower part of the cam chain guide in place.


I drained the oil through a screen to check for bits, and I checked the oil pickup screen when the oil pan was off. I ran a magnet around wherever I could while the motor was opened up. I couldn't find anything.


I did not cut open the oil filter. I figure to get in there a part would have to be small enough to pass through the oil pickup screen.


Cheers


Jesal

[Steve in Sunny Fla]

to me it looks like the most likely place for something to get lodged would be on the left side of the rotor, right at the engine parting like. the pic looks like there might be some shiny metal there. If so, something got longed there, busted off the fingers, and then fell to the bottom.

[Egodriver71]

Very unusual problem

Good troubleshooting though

[ZXtasy]

Very nice informative post about an anomaly...good work and hope it was just a fluke.

[Boomer]

If ya blow up Jesals photos, the grain on the breaks are too uniform for something hitting them.
I suspect one came off due to a stress fracture and the imbalance the caused the rest to vibrate until they also fractured off. Most likely it's just poor manufacturing of that one part.