SR Conversion to MSD Ignition

XT/TT 500 Yamaha Parts required for conversion:

• clutch cover
• 21T crankshaft driver gear
• point shaft with gear
• 9mm ID inner thrust washer
• 15mm ID outer thrust washer
• governor (mechanical advance) with hold bolt
• Points plate with points and condenser with mounting screws
• Points cover with mounting screws

MSD Ignition Parts required:

• MSD 5 Ignition Part No. 5900
• MSD Blaster 2 coil Part No. 8202

Other Parts required:

• universal coil mounting bracket
• 1 1/2" x 8" aluminium angle
• 8mm spark plug wire 27" long
• spark plug, MSD suggests one heat range colder than stock and increase gap by .010" to .015" over stock.

Uncommon tools required:

• 9mm reamer
• 4 drill bushing you probably have to have made
• 15mm OD x 3/16" ID x 2" long
• 15mm OD x 5/16" ID x 2" long
• 15mm OD x 11/32" ID x 2" long
• 15mm OD x 9mm ID x 2" long
• 3/4 Spot Facer with 9mm pilot

Remove the following items from the bike:

• left side cover
• right side cover
• seat
• CDI box (to the rear of the battery box) and discard
• gas tank
• ignition coil and discard
• exhaust pipe
• right foot peg
• kick starter arm
• rear brake lever
• drain oil from frame oil tank.
• drain oil from engine by removing plug under engine.
• skid plate
• oil screen cover from bottom of engine.
• remove old clutch cover and discard.

Install Points Driver Gear:

• remove the nut from the end of the crankshaft
• remove spacer from the end of the crankshaft
• install small point driver gear on crankshaft, it is indexed, and reinstall nut on the crankshaft

Preparing Cases for point shaft:

• cut a hole off center in the bottom of a dixie cup to fit over undrilled casting boss on engine case, hole is off center to clear cam chain. Cut a little off top of the dixie cup if necessary to give good seal this will catch the cuttings from drilling the case.
• temporarily install new clutch, cover tighten screws for good alignment.
• insert first drill bushing in the point shaft hole of the new clutch cover.
• drill pilot hole 1” deep using 3/16” drill bit
• insert second drill bushing
• drill hole 1” deep using 5/16” drill bit
• insert third drill bushing
• drill hole 1” deep using 11/32” drill bit
• insert fourth drill bushing
• ream hole 1” deep using 9mm reamer
• remove screws and clutch cover being careful not to spill cuttings from dixie cup empty and clean dixie cup and reinstall on case
• using 3/4” counter bore with 9mm pilot, spot face case casting you just drilled until the driver gear on the crankshaft align plus a little. I couldn't find any specs for shaft end play but I think loose is better than tight. The gears are strait cut and should have very little side loading.
• in the back of the newly drill hole you will find a smaller hole thru to the inside of the engine cases. This must be cleaned of all cuttings. You can use a small drill to augar out the cuttings to the outside of the hole using the dixie cup to catch them.
• Any remaining cuttings must be flushed out of the engine through the oil screen cover hole that you removed from the bottom of the engine.
• install point shaft making sure you have installed the 2 thrust washers, one on each end.
• reinstall clutch cover, with gasket, to check for end play on point shaft. It’s pretty stiff so you may need to put the screw in the end of the point shaft so you can get a hold of it.
• If end play is OK, reinstall clutch cover.
• Replace oil screen cover on bottom of engine.
• Replace skid plate, rear brake lever, kick starter arm, gas tank, exhaust pipe and right foot peg.

Mounting of MSD 5 ignition with MSD Blaster 2 coil:

• Mount MSD 5 box behind the right side cover (air box removed, I don’t know where you would put it if you still have the stock air box) with a piece of 1 1/2” x 8" aluminium angle.
• Mount MSD Blaster 2 coil on rear fender. I used a universal coil mount bracket.

Stock wiring modifications:

• At main switch cut Black/White wire and attached to Brown wire . This gives switched 12v to the new ignition system.
• At the 3 wire connector where the old CDI box hooked in, Orange wire is not used. Black wire is not used (ground). Black/White wire to + (positive) side of coil.

Wiring of MSD ignition:

• Black/White from stock wiring harness connects to the + (positive) side of the coil.
• White wire from MSD 5 goes to points.
• Red wire from MSD 5 to + (positive) side of coil
• Orange wire from MSD 5 to - (negitive)side of coil.
• Black ground to good chassis ground or negitive side of battery
• Install a 8mm plug wire 27” long.

Reinstall the following parts:

• left side cover
• right side cover
• seat
• gas tank

Set point gap and timing.

Start it and go for a ride, that's what it's all about!

Any questions, comments or corrections, please e-mail me.

Ron Sutton's Home Page