My Yamaha Build

​I did a plug chop / choke test, and the spark plugs are looking a bit lean (pics attached), so it seems I need to step up the main jet size. Engine runs to 10-11k rpms. Or dashboard is false, but it…Read all

I'm getting an exhaust leak / air blowing past the joint where the exhaust connects to the cylinder. Do not have any gasget for that exhaust. What can i use for making gasget?

Reflecting on the build process from the bare frame and failed bearings to the finished preservation. This Yamaha is the perfect mix of restored mechanicals and original 1976 soul.

The RD250 is back on the road! Need work with jets and sync, but for now runs better than it has in years.

Turns out the choke / starter plunger wasn't sealing properly when switched off. Because of that, it was constantly drawing extra fuel into the engine, making it absolute hell to tune the carbs. ​A…Read all

Dialing in the ignition timing using a dial indicator in the spark plug hole. Precision is key for these old two-strokes. I set spark 1.8mm before TDC

The RD is starting to look like a motorcycle again. The black frame and engine cases provide a great contrast to the original blue tank. Wiring harness is next on the list.

Swapping the crusty old expansion chambers for a set of polished DG performance pipes. These should really wake up the 250cc twin. The fitment looks great against the freshly painted frame.

Starting to build the bike back up. I've got the refinished engine back in the frame and mounted some fresh Bridgestone Battlax BT46 tires. Keeping the original pitted chrome on the shocks to maintain…Read all

To improve the compression ratio, I'm measuring the squish clearance using the solder method at TDC. The heads have been machined, and I've noted the deck heights to ensure everything is optimized for…Read all

The cylinders are back with a fresh satin black finish and a 0.25mm oversize bore. I'm checking the oil pump gear and getting the new pistons ready for assembly. Everything is looking much tighter now…Read all

Splitting the cases on the two-stroke twin. I found some surface oxidation on the crankshaft and significant blow-by on the pistons. The transmission gears look solid, but those pistons definitely nee…Read all

Finally got the RD250 down to the bare frame. The double-cradle steel frame is ready for a fresh coat of black paint to stabilize the chassis while I work on the engine internals.

Tearing into the carbs and engine reveals years of fuel varnish and oily sludge. The Mikuni internals are pretty rough, and the drive sprocket area is caked in decades of road grime. Time for a deep c…Read all

I'm starting this 1976 Yamaha RD250 preservation project. The goal is to keep the original blue paint and patina while refreshing the mechanicals. Looking at the engine and suspension, there is plenty…Read all