Guess I'm lucky it broke BEFORE the trip!
#1
Guess I'm lucky it broke BEFORE the trip!
It literally broke one block away from home, but I was able to ride it into the garage. No, this is not another "M8 engines suck" thread. The issue isn't MoCo's; it's mine. I was set to leave for the Rockies in exactly one week, so I am fortunate that I wasn't there when this happened. Here's the situation: My bike is tuned with the PV-2 in accordance with my mods. I did three auto-tune sessions to get it dialed in after the header was installed last year. The bike has always performed strong and ran flawlessly. I had an occasional but rare detonation knock only when blipping the throttle slightly from idle, like before accelerating. I modified the tune slightly to overcome this, and it's been fine up until yesterday after 80 miles of high-speed riding on the interstate.
One blip, one sharp and loud detonation event, then it stalled. Started hard with a misfire. Uh-oh. I believe I hear compression leaking into the exhaust.
Best case: broke a spark plug and the perceived compression noise in the exhaust is imaginary. Not likely. Worst case and more probable: broken compression ring and/or piston. If it's the latter, I guess I'll be talking to our friends at Fuel Moto about their 120 big bore kit. I was going to do it down the road anyway, so I guess this might be fate telling me to go big or go home early. I'll report back after I have some time to diagnose. Maybe I'll get lucky and one of the compression release solenoids stuck open.
One blip, one sharp and loud detonation event, then it stalled. Started hard with a misfire. Uh-oh. I believe I hear compression leaking into the exhaust.
Best case: broke a spark plug and the perceived compression noise in the exhaust is imaginary. Not likely. Worst case and more probable: broken compression ring and/or piston. If it's the latter, I guess I'll be talking to our friends at Fuel Moto about their 120 big bore kit. I was going to do it down the road anyway, so I guess this might be fate telling me to go big or go home early. I'll report back after I have some time to diagnose. Maybe I'll get lucky and one of the compression release solenoids stuck open.
Last edited by strych9; 08-06-2018 at 10:17 AM.
#2
#3
Thanks. I've moved past the 'acceptance' stage. Now I have to focus on determining the cause and getting it back on the road. I knew the risk when I tuned it; now I have to walk the walk and take it in stride.
#5
And that is how it’s supposed to be. I have cam tools and the factory service manual. I can loan them to you or take pics of pages, if needed... let me know if I can help.
The following users liked this post:
strych9 (08-07-2018)
#6
#7
Trending Topics
The following users liked this post:
strych9 (08-07-2018)
#10
Great advice! I was just going to unplug them but disabling them is probably a simpler option. Thanks again.
The following users liked this post:
cmashark (08-07-2018)