Blown Motor Opinions


Looking for some wisdom from members here. Picked up 2004 400 S 5900 mi. New head about 1500 mi. ago according to PO dropped valve. No skid plate had hit rock resulting in this:


which led to this:




Cases have been split and no visible damage to lower end. Bearings look and feel good. Was some water in lower end. Radiators were low to about level of head leading and some white powder from evaporating water on top of piston leading me to believe water in case coming from above piston.


Is this worth cleaning up and trying to use or need all new bearings etc.?

Head to Eddie?

Is this valid assumption on water in crankcase?

Did not notice this washer on disassembly but was found in case.Anybody recognize and supposed to be bent like this?


Do these pencil #s indicate this case has been split before. There are quite a few of these written around bearings?


And a couple more pics:




Sorry for long post just trying to decide whether to fix or part out bike and use for spares for my main bike.



Not having it in my hands to inspect.. I would assume it's needed a complete rebuild from the pics and description you posted. The first thing I would do is look at the the oil pump and oil pump cavity in the case..if not scored badly,, then.. I would assume and recommend a Hot Rods crank (4mm stroker), new main bearings, obviously a top end kit :cheers: (cylinder works 434 BB kit makes sense) Send the head to Eddie for inspection and refresh as needed. The cams need to be checked for wear and every transmission bearing / shaft for wear.

Thanks for quick response. No scoring in oil pump cavity. How hard to change main bearings?



Looking at the damages, I would check up with Eddie to get a "new" engine from him.

Needing new case, probably a new rod, cylinder, bearings and so on.....

Ps. the washer looks like the one on the cylinder bolts

Thanks for quick response. No scoring in oil pump cavity. How hard to change main bearings?



ahhh.. that depends.. easy if you know what your doing, impossible if your the guy that lives down the street from me who owns only two tools a hammer and vice grips :cheers:

If you have split the case, your most the way there..

Bearing plate and puller or bearing plate and a hyd press , they will come right off. Oven and freezer... they will go right on.

That washer probably goes between the case and the shoulder bolt that the shift detent lever pivots on.

Not clear on 1 thing. You bought it in this condition? OR this happened to you?

Easy to change main bearings. Tap out the old ones. Heat the cases to 300 F and drop in the new ones. (the bearing are in a steel liner so heating does not help in the removal process)

To remove the transmission bearings, heat to 300F then tap the case on a wooden block and the bearings should fall out. If not, tap out with a drift. There is one blind bearings that may require a blind bearing puller.

I see this as a perfect excuse to get a fire breathing 470 engine from eddie:smirk:


Bought knowing in this condition. Very cheap. Frame bare worth more than I paid. Bought with intention of a whole bunch spare parts for my main bike. But now wondering if worth fixing.


Looking at the damages, I would check up with Eddie to get a "new" engine from him.

Needing new case, probably a new rod, cylinder, bearings and so on.....

Ps. the washer looks like the one on the cylinder bolts

That's what gets my vote. Then you can fleabay all the other parts.

Why on earth would someone run it in rocks with no skid plate?


Looks like the last mechanic was a monkey with a crowbar.

Is a shame as rest of bike in great condition.


I'd get another engine for it.

budget the cost of all the new part you need plus your labour......vs a new used engine.

Best thing i ever did was buying an engine from Eddie

Thanks for all reply's. Still trying to find where washer came from. Does anybody know if it may be the one that goes behind cam chain tensioner pivot? Anybody chime in on the penciled numbers on case?



Did you check out my earlier reply? Shift drum detent pivot shoulder bolt.


I seen that but I think this washer is to small to fit there. Will double check though.



The washer I'm talking about is a 6mm ID washer. Plain finish (no zinc). Goes between the shoulder and the case. You don't know it's there when you take the roller detent off, then find it later on the bench.

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