A peek inside my '05 DE250

[AZRickD]

While it was up on the stand (tire changes) I decided to take off the pipe (to straighten it), and take some pics of the piston and stuff in preparation for my June-ish top-end inspection and R & R.

A series of photos starting with the exhaust area.

The photo's aren't showing so just click on the links...



Next is a pic of the side of the piston (no rings showing)...



Next is the top of the piston with a little ring action...



And finally a glance at the back of the cylinder wall. Notice the cross-hatching direct from the Spanish factory...

[Eric K]

It looks like you have a lot of carbon in there.

[GMP]

Thats due to come apart. What oil was run in that bike? Very dirty PV, my bikes PV parts and exhaust port have been little more than stained brown running Amsoil.

[AZRickD]

I run Maxima at 40 to 1.

Usually jetted just a little richer than optimum.

One thing to keep in mind is that digital flash photography (mine was in Macro mode), makes things look pretty nasty. It's like watching your local news on Hi-Def and discovering that your the hot news anchoress has an issue with wrinkles.

[AZRickD]

In two weeks I'm going to do my top end (with the help of a mucho-experienced buddy).

We'll do the squish band measurement for RB-Designs and then commence with the tear-down. We'll give everything a good cleaning and see if my deck height is where it should be.

I'd appreciate some advice on the best vendor and manufacturer for the gasket kit, piston and rings. I've used Wiseco before but I've always been concerned with the forged piston heat cycle thing. I'd be willing to consider others.

Thanks.

[Eric K]

The dimension to the top of the piston varies by manufacturer. The top of the replacement Vertex piston was 0.2 mm higher than the original piston as measured by squish. I would measure the squish after installing the new piston.