Bonneville America Forums Forums Technical Forums Performance Mods Houston, we have a problem...

Ok, hi, all. Remember i went and got a big-bore kit? Well...

so i'm riding to work yesterday a mile from home through a school zone. Taking it easy, about 35mph... when the engine cuts out and the rear tire locks.

I have enough time to say "what the f..." at which point i'm ****** over tea kettle. Both the bike and I sustained some damaged, but with a little luck we'll both live.

When i got the bike upright and off to the side, i hit the starter and she fired right up.

i have absolutely, positively no idea WTF just happened. And i'm more than a little curious as i'm goint to have to have my left thumb pinned to mend the spiral fracture therein. and my right shoulder hurts like ****** from where i landed.

So, gurus... got some ideas here?

--Jaeger

Glad you're ok(ish).
Heal yourself first and then fix the bike.

Too high a gear, lugged/stalled the engine?

i would check the compression on each cylinder. not much is going to kill the engine and lock up the rear end save a seize. Bad wheel bearings would. or overheated brakes. Did you do a face plant? Or a lowside? Whatever, glad you are sorta Okay! One of the riders on that 'other site' said he had a 10mm bolt wedge into the drive-chain which caused him to inherit the tarmac, so to say. inspect your chain for tell tail marks of something wedging tween the chain/sprocket and swingarm/engine case.

Check the bolts that hold the rear sprocket on. Chain real, real loose, high siding it on the sprocket? Tough luck there. Glad you're okay!

i'm back, sort've -- left thumb is pinned and in a cast so it's hard to type.

i dunno what gear i was in, 3 or 4. wasn't lugging at all, really -- and if i were, it still shouldn't lock up the back tire like that. wnet over the bike yesterday and she runs and shifts fine. frame seems ok as well, so i think she's fixable. :)) (big sigh of relief.)

but i STILL don't know WTF happened.

nothing caught in the chain.

bike shifts through gears while engine running

wheels free and clear

... so i dunno.

otherwise, i can report that i'm not impressed with the "highside" experience and would discourage others from trying it. :P

--Jaeger

If you did lug it down far enough to stall it would cause the rear tire to lock up briefly. Enough to dump you over in a low speed turn. Not saying you did that but it is a possibility.

it's possible but i really doubt it. we, as i recall, buzzing along quite nicely.

then again, she was cold that morning and i wasn't far from home... and the new bb kit is higher compression...

dunno. we'll see. i'm going to send her to d&d in norfolk i think to get them to give her the works, make sure all's ok, and get the new clutch in.



--jaeger

I'm betting unfortunately, that the engine seized.

Clay

Maybe not. Barring a broomstick through the spokes or a really hard-shelled insect riding on the chain something stopped the engine dead. If it isn't in the top end, maybe there's some foreign object lying in wait in the bottom end of the engine. Something told the engine to quit turning NOW. It may have gone back to it's lair, waiting to pounce again....

How many miles do you have on the BB kit? I'm thinking that might be piston seizure.

I hate to say this but if you really think it was any kind of seizure you should not ride it or start it again until you tear the engine down and find the problem. If it seized even a little you have done damage. If it ran after that the damage may be minimal now and a tear down may save you parts and money and avoid a possible crash later when ir seizes at highway speeds. If you think you just lugged it down and caused it to stall, then just don't do that!

Update: dropped the bike back at D&D yesterday and Brian said they're gonna diagnose it this week. He, too, was baffled at the whole affair, and said that the drivetrain on these bikes is ****** near bulletproof, and that he's NEVER seen a transmission munch-up in any of the Bonneville variants.

He also basically said "don't worry about it, we'll get it fixed." I hope he's right!

(And I'll also get some proper dyno results from all this, which I'll post up as soon as they're available.)

Wish me luck!

--Jaeger

Good luck Jaeger, and be sure to put thoose numbers up when you get it dynoed


/Johann

hope its not to big a deal. goodluck with it

Luck!

UPDATE:

Just talked to the insurance company working with the shop -- the shop says they found a shorted out wire that was touching the engine intermittently, which likely caused the stall. The engine, transmission, clutch, etc -- all are fine.

just talked to the shop and they said the bike stalled out on them on the lift, which is when they found it.

They'll get her back together and on the dyno, and I should have results next week!

--Jaeger

thats great news, make sure you post the sheet/numbers

that is good news. best of luck.

Will do. Originally I was told it was the coil wires, but talking to Brian at D&D he said there was another wire of some sort that "passes through a baffle" that had worn through the insulation just enough to make contact... but only when the bike was bumped or vibrated the wrong way.

Once I know precisely what that wire is I'll post that up too. They said the vibrations had just slowly worn away the insulation.

--Jaeger

Jaeger, glad to hear you are ok... and that the bike is going to be ok too. Get everything back ship shape and lets do some riding this season.

That's why I keep mine stock...no mods, no probs....33k now, sweet as new.

1st Jaeger, I hope your feeling better. 2nd doc by the statement you posted here your thinking because our budy JAEGER did a couple of mods to his motorbike somehow he is responsible for a bare wire shorting out on the frame. Using that same line of thought I've had my bike apart a couple of times and cut a bunch of pieces off and generally fiddle with it all the time. 30k and no problems, to hear you tell it, I should have been assoverbars years ago.

20,000 with no problems and I have cut every wire in my handle bars and the wires from the headlight are back under the tank now. I put a custom billet headlight on my bike so no room to run the wires into it. I ran all my wires inside my handle bars and no issue there either. Not to mention all the other things I have done to my bike and all the things I did to Wendy's bike, including the wire changes.