Lost compression and pushrod movement

[DanB]

I was out for the last ride this season (northern Illinois having a v warm day) and riding along the fox river. My 06 Electra was running fine!

Came off a stop light, not hard, and 'thunk' lost power at 40 mph. Didn't lock anything up.

No compression in chamber. Looks like exhaust Value stuck open. Push rods not moving, but the engine kicks over and pressure blows out the breather. No nasty sounds on kicking over. Think the piston is fine. Just no functioning values nor value train. But... The sprag is ok!

I'm thinking this is not good. Unlikely both push rod cams failed. But the pinion drive off the case into the timing box. Don't know the exact names of these parts.

Luckily this happened 1 block away from RE dealer (Scoots4U, Bob Piltz). His going to have a look and tell me how bad it is.

So what do you all think?  Could start a running pool?

[Arizoni]

It sounds like the exhaust cam gear lost a couple of teeth if neither push rod is moving.

I would think this would be most unusual but I can't think of any other simple explanation.

[DanB]

Thats what i was thinking. But then, wouldnt the intake still turn?  Both pushrods were dead in the water so to speak.

Ill be looking over the parts diagrams and pete's manuals tonight.

[Arizoni]

I don't know how the AVL is putting the power thru the cams but the Iron Barrel drives the exhaust cam gear with the crankshafts gear.
The exhaust gear in turn drives the inlet cam gear.

[DanB]

Think you're right Arizoni. Looking at the parts drawings, it looks like the timing pinion on the crank hooks up to the exhaust cam gear. Its strange that i cant get either value or pushrod to move.

Hope its not a crank timing pinion failure. Really dont relish the idea of splitting a case this winter.  I wonder if BW has any cams left....

[LarsBloodbeard]

You would be correct, on the iron barrel.  One failure in that chain of gears and the whole thing is screwed.  No idea on the AVL though.

[ace.cafe]

The AVL drives the cams the same way.
No need to split the cases to replace the pinion gear, if that's what's wrong.

[Bullet Whisperer]

Think you're right Arizoni. Looking at the parts drawings, it looks like the timing pinion on the crank hooks up to the exhaust cam gear. Its strange that i cant get either value or pushrod to move.

Hope its not a crank timing pinion failure. Really dont relish the idea of splitting a case this winter.  I wonder if BW has any cams left....

It might be the case that the small key in the timing pinion has sheared and if you're lucky, this might be all you need to replace to get up and running again. I confirmed an order for another batch of six sets of of 'S' cams to be made nearly two months ago, but they haven't materialized yet, despite my numerous 'reminder' calls to the cam makers. Any day soon, perhaps?
 B.W.
 

[Arizoni]

I think you might have nailed the problem with the idea that the little drive key in the crankshaft pinion sheared off although I would think there should be some tension on the nut that holds it in place.

That would be a totally easy fix if that's all that is wrong.

[barenekd]

Either the timing gear has spun loose, or the crankshaft timing sshaft broke.
Bare

[barenekd]

No compression in chamber.

Even if your valves are closed, you won't have any compression. If it can't suck in any air, it can't squish anything.
Bare

[DanB]

Good point Bare on compression.

The shop was closed today so I hope to get in there tomorrow.  I'm praying it's the gear or the pin that just gone and not the shaft. I'll know shortly and will share

[DanB]

Just a quick update.

Talked to Bob at Scoots4U. It's the exhaust cam follower. Snapped right off.

It then proceeded to bounce around for a little bit and end up between the teeth of the inlet & exhaust cam gears. Think he said the exhaust cam is now missing a few teeth.

So, the crankshaft appears ok (whew!). The rockers and valves appear ok. Timing pinion and key ok as well.

Top end needs to come completely off to replace the follower on the case.

Hoping to get over there tomorrow to have a look myself. It'll be a learning experience.

While the top end is off, any suggestions for basic improvements? It'd love to convert to a 535, just don't have the funds.

[LarsBloodbeard]

Well, you aren't going to convert to 535 for free, but you can always take your barrel to a machine shop and have it honed to 87mm and get a larger piston.  That'd be the cheapest way.

If you're looking for cheap or free upgrades, you should probably take a different approach first.  Better flowing air filter, drill out your exhaust, stuff like that.

If it was me, I'd put in upgraded cams since you're replacing them anyways.  I'm not too familiar with what's available for your model though.

[DanB]

Update.

Pulled the top end. Replaced the cam follower and the cam gear. New gaskets, put it back together.

Timing not right. The pinion gear snapped the key on the shaft, then twisted itself onto the shaft. So much so, the puller is useless. So need to try and cut the pinion gear off without damaging anything further.

Decided the upgrades are not that important right now.