RD400 Engine Question

[billy mild]

I'm looking at a RD400 that is in good overall shape. Its a little worn around where the tank touches the seat, but comestically in really good shape for a bike of its age. My concern is the bike doesn't run currently. Feels to have good compression, but supposedly it won't stay running. The owner suspects something electrical. I was thinking it could be a bad battery. My old AT1 won't run correctly unless it has a good battery. The owner said he could ride the bike around the block and it would die. There would be no power. Sounds like a bad battery and the alternator can't keep up.

The wiring harness looks to be unmolested to me. He is on the high side for a bike that doesn't technically run. He wants $3000. I was thinking more along the lines of $2000 or lower.

 

[VonYinzer]

Not running, $3000 is laughable.

It's likely a combo of a bad battery and possibly a bad coil. RD coils aren't the best.

That's the easy fix. It could also need timed or have bad rings. You'd need to do a proper compression test to determine the latter.

All that aside, factor in a seal/gasket replacement as soon as you get it. If they're original, I can gurantee some seals are shot. That can lead to very very bad things. It's about $50-$70 for a full rebuild kit. Yoi will have to tear the motor down as well. All things that should proceed to lower that astronomical price even more.