Yamaha set it up that way so it should be ok to use the starter from cold.
Then again they did a few things that time has proven not to work so well.
I might consider using the safety relay from a later model, one that turns the headlight on after the engine starts. It shouldn't be hard to adapt it into your wiring.
Your bike uses blue/white wires for the engine stop switch, the later red/white.
The 80 up has a red/yellow and a blue/black wire. Power comes in on the red/yellow and goes out on the blue/black. This sends power to the reserve lighting unit and light checker. They work together to control the headlight. Turn it on and turn on the other element when one burns out.
In your case you can run the red/yellow from your key switch to the red/yellow of the safety relay, the blue/black from the safety relay to the red/yellow that goes to your dimmer switch.
I think you can do this with just unplugging the red/yellow just after the key switch. I think the red/yellow is in a single wire plug in. Just unplug the wires and plug wires in to reach the safety relay. At the plug for the safety relay you may have to rearrange the wires to match your harness.
I wouldn't change any of the wiring on the bikes harness, just on the safety relay side of the plug.
It doesn't sound like a hard task. This will turn the headlight on after the engine starts.
If the engine stalls after you start the bike the latch on the relay will keep the headlight lit. So to turn the headlight of when starting in that circumstance you will need to turn the key off and back on. This unlatches the relay.
Or wire in a lighting relay like used to power extra lights on a car. Just use the yellow wire from the alternator to trip it on after the engine starts. Wire it into the red/yellow like the safety relay to 30 and 87 on the relay and the yellow wire to 86, ground 85.
On adjusting the decompressor cable, I don't find it in my manuals. I would remove the decompressor cover off so I can roll the engine over to get the exhaust valve under the decompressor fully closed. The same as when you adjust that valve for clearance.
Then install the cover, adjust the cable to 1/8 inch or so free play. This should let the valve operate normally unless the lever is pulled, then it should open the valve to close to the max amount the decompressor can open it.
Much tighter and it may interfere with the normal valve operation, much looser and the decompressor may not open the valve enough.
To see if the valve is actully opening, I might leave the key off, kick it over with the kick start a few times, then pull the lever and kick it a few more times. If the decompressor is working the engine will kick over easier with the lever pulled.
In the manual under the starter section they list the starter as pulling 35 amps draw while cranking the engine with the decompressor lever pulled, 20 degrees C. It goes on to say At 300 rpm at 75 A or less.
So even with the light on, using the decompressor cuts the starter draw about in half.
With the decompressor pulled your only cranking a 325 cc engine.
I think as long as your charging system is keeping the battery fully charged it will start fine with the decompressor cold or warm.
Try it and see how it starts.
Leo
Then again they did a few things that time has proven not to work so well.
I might consider using the safety relay from a later model, one that turns the headlight on after the engine starts. It shouldn't be hard to adapt it into your wiring.
Your bike uses blue/white wires for the engine stop switch, the later red/white.
The 80 up has a red/yellow and a blue/black wire. Power comes in on the red/yellow and goes out on the blue/black. This sends power to the reserve lighting unit and light checker. They work together to control the headlight. Turn it on and turn on the other element when one burns out.
In your case you can run the red/yellow from your key switch to the red/yellow of the safety relay, the blue/black from the safety relay to the red/yellow that goes to your dimmer switch.
I think you can do this with just unplugging the red/yellow just after the key switch. I think the red/yellow is in a single wire plug in. Just unplug the wires and plug wires in to reach the safety relay. At the plug for the safety relay you may have to rearrange the wires to match your harness.
I wouldn't change any of the wiring on the bikes harness, just on the safety relay side of the plug.
It doesn't sound like a hard task. This will turn the headlight on after the engine starts.
If the engine stalls after you start the bike the latch on the relay will keep the headlight lit. So to turn the headlight of when starting in that circumstance you will need to turn the key off and back on. This unlatches the relay.
Or wire in a lighting relay like used to power extra lights on a car. Just use the yellow wire from the alternator to trip it on after the engine starts. Wire it into the red/yellow like the safety relay to 30 and 87 on the relay and the yellow wire to 86, ground 85.
On adjusting the decompressor cable, I don't find it in my manuals. I would remove the decompressor cover off so I can roll the engine over to get the exhaust valve under the decompressor fully closed. The same as when you adjust that valve for clearance.
Then install the cover, adjust the cable to 1/8 inch or so free play. This should let the valve operate normally unless the lever is pulled, then it should open the valve to close to the max amount the decompressor can open it.
Much tighter and it may interfere with the normal valve operation, much looser and the decompressor may not open the valve enough.
To see if the valve is actully opening, I might leave the key off, kick it over with the kick start a few times, then pull the lever and kick it a few more times. If the decompressor is working the engine will kick over easier with the lever pulled.
In the manual under the starter section they list the starter as pulling 35 amps draw while cranking the engine with the decompressor lever pulled, 20 degrees C. It goes on to say At 300 rpm at 75 A or less.
So even with the light on, using the decompressor cuts the starter draw about in half.
With the decompressor pulled your only cranking a 325 cc engine.
I think as long as your charging system is keeping the battery fully charged it will start fine with the decompressor cold or warm.
Try it and see how it starts.
Leo
