1/24/15

DT1 MX project

I got the clutch on, and started polishing the clutch cover, so the bottom end is just about ready to button up.
101_0639

I've got the cylinder porting nearly done. I just need to finish up with sand paper and polish the exhaust port, and then get it out for boring.
101_0641

101_0645

101_0649

101_0650

101_0651

101_0654

DT1 MX project

I'm using a complete seal kit from Rusty Riders.
101_0459

Here is the kick start assembly cleaned and ready to reassemble.
101_0615

An example of things to look for when reassembling parts, there is a mark on the ratchet wheel that needs to line up with a mark on the kick axle so that the torsion spring has the correct tension.
101_0624

Here it is assembled.
101_0627

After the clutch is back on and the covers polished, the bottom end will be done.
101_0633

The cylinder I'm using is at the 1st oversize (70.25mm), but has some scoring and will need to go at least one more oversize. Before boring I'm going to do some mild porting, so wanted to get it cleaned up first. I bead blasted it.
101_0511

101_0514

One of the best ways to loosen carbon buildup is to use paint stripper.
101_0516

It melts most of it away, and a brass brush helps get the tougher carbon.
101_0526

I then pressure washed it to remove the paint stripper and any left over blasting media, and brushed ATF on the iron parts to prevent flash rusting. Here you can see some of the cylinder wall scoring.
101_0532

101_0534

For the port work I'm just going to smooth and blend some of the rough areas of the castings, like in the exhaust port shown here. Once that is done I'll take it to the machine shop and see what oversize it will need.
101_0636