DR350se Busted Exhaust Valve

[PilotNut]

I just picked up a 1997 DR350se that the seller claimed had a "stater problem". The price was right so I took a chance. Turns out the starter wasn't the problem. The motor is locked-up due to an exhaust valve failure. From what I can see through the exhaust port (haven't pulled the top end off yet), one of the exhaust valves broke off inside the motor.

Before I dive into this potentially costly repair, I need to research/locate/price used parts.

I see lots of used parts for the off-road version of the DR350, my question: are the top-end parts for the "dirt" version of the DR350 the same as for the "street" model? I'm concerned about things like cam timing and the decompression mechanisms (manual vs auto) among other things that may be slightly different in the top-ends of the two models.

Any help, comments or suggestions would be appreciated.

Thanks,

Marc

[TN2Wheeler]

You probably know that In 1994 when the S model got electric start, it also got an automatic compression release. You'll want to be sure any head or valve train component you replace is compatible with that. Other than that, I've swapped heads across years and on/off road models on several occasions without issues. I do know that a 1997 off-road model (kick start) from which I stole the engine for my S chassis had BOTH the automatic and manual compression release. The manual compression release is important on the kick start model because it funcions as a crank positioner to allow kicking through a compression stroke. As far as I know the the S model hasn't had a manual release since 1993. I don't believe the cam timing is significantly different between the off/on road models, you'd have to study the service manual for those specs.

What you'll probably find in that motor is excessive cam chain wear or a failed cam chain tensioner that allowed the cam to jump time and subsequently the now broken exhaust valve was struck by the rising piston. Most likely the head and piston are toast due to combustion chamber/piston crown damage from the shrapnel and there may be cracks around the valve guides. Bottom line it will be a lot more expensive than just replacing a broken/bent valve but it is repairable and is probably worth the cost. The DR350 is still my all-round favorite dual sport bike.

[PilotNut]

Thanks for the information. Can you point me in the direction for a source of good used parts? If I cant find what I need, its heading for ebay "as is". The rest of the bike is in really nice shape and it has a clean tile.

[TN2Wheeler]

If it were mine I'd look for a running late model off road model as a parts donor. The ones without a title usually sell pretty cheap. Buy the bike and use the parts you need. Part out the rest on eBay. '97 and newer off-road models have a better suspension than your '97 S model. BTW, where is this bike?

[PilotNut]

Good advice - the bike is located in central NJ

[PilotNut]

I tried to upload a pic of the bike but the upload failed

Edited February 14, 2013 by PilotNut

[PilotNut]

Just found this down in your neck of the woods (Mt Juliet, TN). Wanna do me a favor and buy it and send me the motor? You can have the rest of the bike...

1998 suzuki dirtbike runs great rear tire almost new has new tire for front needs nothing just a new rider $950 call david 615-474-9909