| Author | Message | ||
     Sarodude |
Someone else was riding the bike. I can't tell you exactly what happened in the seconds prior to the event. Plated oversize cylinder with matching piston. Head is in remarkably good shape. Worried about the bottom end.      -Saro | ||
| Road_thing |
Ouch. Looks like only half of the cylinder is plated anymore! Did a valve hit the piston and knock that chunk off? If the valves are OK, you may have experienced some big-time detonation. That sucks, I hope the bottom end is OK. rt | ||
| Sarodude |
Head appears TOTALLY intact. I was shocked. Detonation is tops on the list. Our kid was riding the bike and I'm really not sure what it had been doing. Bad gas? Intake leak? The intake boot & o-ring were replaced when I did the top end. Didn't even have 1000 miles since that. I'm curious if I should just take my lumps and split the bottom end or ??? -Saro | ||
| Naustin |
You know the Blast's tendency to tear intake boots... That would be my first guess, especially if you had it off and replaced it within the last 1000 miles. Seems like they last forever, or they tear right away. But, I don't know if the damage is consistent with a really bad air leak or not? | ||
| Littlefield |
Do you think the piston failed first or the coating? I assume this is a repair coating put on the bring the cylinder back to size or is it standard on that engine? T | ||
| Bluzm2 |
Looks like you have seize marks in the 3rd photo above. Oil starvation? The top ring land is snapped right off on the same side. I would think that would be a seize or an impact. No dings on he head though... What kind of cylinder? How many miles on it? Looks like a good solid plating job on the part that separated, nice even thickness... I think we need the Queen to offer her expert opinion. Oh Pammy!!! Brad | ||
| Sarodude |
Cylinder is an Axtell Nicom plated jug - 3 9/16" bore. The bore keeps distracting me from the piston damage. Piston sure could be detonation induced. Just kinda freaked out by the extensive plating damage. Now that I think about it, an intake leak isn't unlikely. We run the Pro Series intake unbraced. This has never been a problem - except that we have a new rider on that bike now who is likely squeezing against the intake. The bike wound up going like 15,000 miles on ONE intake boot until it finally tore on the hottest day in the summer riding through the valley, uphill, with my wife half trying to keep up with a guy who'd just broken in his bike and half wondering why her bike wasn't moving too swiftly. I haven't ridden the bike in some time. I don't know what condition it was in when it popped. I don't even see any damage to the intake boot now. Incidentally, the motor never locked up (from what I'm told). She woulda been freaked out pretty good had things locked up. -Saro | ||
| Naustin |
If you have the pro-series unbraced, (and especially if the rider didn't know not to flex it with his leg), I'd bet my balls that was the cause of the failure. | ||
| Pammy |
Detonation could certainly cause damage to the plating. I would like to see the combustion chamber. | ||
| Pammy |
How's about a pic of the inside of the piston as well. | ||
| Pammy |
The case definitely needs to be split. | ||
| Ezblast |
Ouch! | ||
| Jlnance |
except that we have a new rider on that bike now who is likely squeezing against the intake. That will kill the boot quickly. I broke 2 boots on EZ's Blast in 1 day doing that. OTOH, the Blast usually stops running when the boot tears. I've never heard of cylinder dammage, but then again I'm not keeping track either. | ||
| Sarodude |
Ask and ye shall receive.   The lighting is misleading. Underneath the piston it's a dark tan or a light brown. The combustion chamber is darker than it appears in the photo. My stupid valve spring compressor drove me nuts trying to get the exhaust valve out - but there's a little piece of something stuck in there keeping it oh so slightly open. I SO don't wanna split the cases. Oh well. -Saro | ||
| Pammy |
If it were me, I would split the cases. I believe it's a case of 'do it now or do later'. The exhaust valve was difficult to remove? maybe it's bent? | ||
| Sarodude |
Pammy- The valve wasn't hard to remove. The (cheap) valve spring compressor kept slipping off the retainer and I had to leave for work. I'm not gonna skip the case split. I just don't WANT to do it. Been soul serching as to whether or not go with a plated jug again - especially if mine can be replated. If I gotta split the cases, maybe I should go big bore. Is a scraper worthwhile on a Blast motor? Besides lightening (don't think we're gonna go there), what should I consider if this thing's gonna be sprawled across a workbench? No long strokes for me, BTW. -Saro | ||
| Pammy |
The first thing you have to do, in order to squelch "mission creep", is sit down with yourself and decide what your expectations are. Be realistic. | ||
| Pammy |
Also, you are going to strip it anyway. Let the damaged parts be your guide  | ||
| Littlefield |
The plated jugs don't sound too great to me. What are they plated with? If it's chrome, nickel, or something like that it's a mechanical bond, doesn't seem like it would hold up well. Surface prep is the most important thing. Some manufacturers use Nikasil successfully, not sure what it is exactly. | ||
| Gearheaderiko |
Maybe related? Same CP 515 piston, but ones an XB piston (Blast engine). http://www.badweatherbikers.com/buell/messages/201 64/280643.html?1247616374 | ||
| Fast1075 |
Looks like lean mixture to me...the missing piece of piston on the intake side was melted off... |
