Yamaha RD Tech Tips

Dead Battery, Bike Won't Start

RDs will not start without a charged battery. I forget the details, but the jist of it is this. In order for an RDs ignition to work there has to be power there. If there’s no power you will never get spark. You really can’t pop start an RD with a dead battery. I think it has something to do with the charging system having an electromagnet in the rotor. No juice, no magnetism. No magnetism, no juice. No juice, no spark. Simple!

Install Electronic Ignition

Make the switch to electronic ignition and set it up carefully. You’ll never have to worry about it again and the thing will stop overheating/seizing/holeing pistons. They will be much better starters and will run more predictably and smoothly at speed. The lack of points prevents point float and point erosion from lack of lubrication. What are you waiting for?!? By the way, if you're looking for a how to for this job, I never did it (no money), so I couldn't tell you. This is something the racing guys do and it really helps out on the street. I wouldn't have blown up my 250 had it had Electronic Ignition.

Battery Cables

If you get an RD, replace the positive and negative battery cables immediately. The stock ones have about 6 strands of copper in them that probably wouldn’t light a light bulb for too long. Much flexing means broken strands. One of the RD’s I acquired had 2 copper strands holding the positive cable onto the batter connect dingus. Rewiring this will help your bike start and probably extend your battery’s life. Before the mod I’d get a year out of a battery. This isn’t so bad because they’re small and cheap. However, the one I installed after I did the mod hung on for 3 years of light use. Not too bad.

Rear Brake Switch

Don’t bother buying new rear brake switches. The new ones are made of craptacular plastic as well. Go to the boneyard and get a half dozen. That should do you for a while.

Spark Plugs

Buy a box of plugs. You can’t do anything with these things without new plugs in them.

Obligatory Carburator Warning

Remember that scrapping the airbox and installing bullet filters will scrap the idle on any motorcycle, so if you do this, REJET.

Coils

I never did it, but I hear better coils make for better bikes. Cheapo VW bug coils work with a minimum of modifications. The problem is mounting them so that they don’t hang out in the wind. Those that do, look as if they mean business.

Obligatory Carburator Warning Part II

If you install spannies or modify the exhaust in any way, REJET or enjoy the fun of pushing your holey pistoned bike back home.

Two-Stroke Oil

Use good two stroke oil. Synthetic is best for lube/smokelessness but semi-synthetic is good, too. Stick to one brand and drain your tank if you change brands. Buy a case and top off often. There really is no reason not to.