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-   -   Guess I'm lucky it broke BEFORE the trip! (https://www.hdforums.com/forum/milwaukee-eight-m8/1247225-guess-im-lucky-it-broke-before-the-trip.html)

strych9 08-06-2018 10:15 AM

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. :icon_mrgreen:

Fullbore55 08-06-2018 10:30 AM

You have my best wishes, you certainly have great attitude!

strych9 08-06-2018 10:47 AM


Originally Posted by Fullbore55 (Post 17572761)
You have my best wishes, you certainly have great attitude!

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.

tbob 08-06-2018 05:49 PM


Originally Posted by strych9 (Post 17572807)
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.

I can respect a Man when he truly acts like one.You sir are a Man I bet your parents are proud.

cmashark 08-06-2018 09:16 PM


Originally Posted by strych9 (Post 17572807)
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.


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.

cmashark 08-06-2018 09:21 PM

Just a quick thought. You can turn off your compression releases with the PV and do a compression test to see which cylinder is the issue.

Max Headflow 08-06-2018 09:29 PM

Hope you figure out what you screwed up, Might still be able to make the trip but it will be a little shorter.

Add:

Any changes you make to your bike should not be just before a trip. Put at least 100 miles on it.

SWMB 08-06-2018 10:24 PM

Hope your problems a small one. I also really respect your attitude on it.

MTBIG G 08-06-2018 10:39 PM

Hoping for an easy fix strych9.
Curious to see what you find.

strych9 08-07-2018 08:10 AM


Originally Posted by cmashark (Post 17574625)



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.

Thanks, brother! I bought the factory manual when I bought the bike, but the cam tools I do not have. If it comes to that I just might take you up on the offer. Thanks!

Originally Posted by cmashark (Post 17574641)
Just a quick thought. You can turn off your compression releases with the PV and do a compression test to see which cylinder is the issue.

Great advice! I was just going to unplug them but disabling them is probably a simpler option. Thanks again.


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