GPZ died on the road

I was riding my 82 GPZ 750 to fill it up and from a stop sign, it started riding very rough. I thought it was running out of gas, so I opened the throttle all the way and then it rode fine. The only problem was I was going 70 in a 45 zone...

When I slowed down, I kept it in 3rd but it wouldn't go faster than 30mph. I opened the throttle again and it stayed down at 30. When I got to the gas station, I let up a little too much and it died. I had to push it to the pump.

I filled it up and gave it a little gas, thinking it was empty, and tried to start it. It turned over just fine but wouldn't start. I kept trying. Nothing. I tried to push start it and got nothing. A fellow biker came and helped me push it faster and it DID start, for a second, then it died again.

I tried jumping it from a car battery (car was not turned on) and it still wouldn't start.

I've turned the tank to RES, back to ON, several times. I've tried with the choke full on, half on, and off. I've checked the vacuums and I can't find a detached or broken hose.

Currently the bike is still at the gas station. The clerk told me she'd keep an eye on it, and thankfully I'm in Utah County, so I'm not too worried.

The biker who helped me try to push start it said the battery might be the issue, but it was still turning the starter motor without a problem.

I just realized I didn't check the spark. I was having issues riding in the rain about a week ago, maybe the coils finally gave out? How should I check for spark?

Use a spark plug from your spares, or remove one. Hook it up to the spark plug wire and lay it on the cylinder head. Crank the motor and watch the spark plug for a nice blue spark.

If its not spark you might try draining the bowls and trying again when you get close to empty is when you draw the water and trash in the tank

So when you say "nice big blue spark", how big? I checked the spark and cylinder 4 had a tiny, tiny spark, and cylinder 4 wasn't much better. 2 and 3 had noticeably better spark.

I got the bike home. It started and did well throughout the powerband. Unfortunately, getting it into first with the bike off wasn't good to the shifter arm and it broke, so I had to ride home in first.

Is there an example of a nice big blue spark somewhere that I can gauge off? I've wanted to upgrade to Dyna S and new coils, so here's my excuse to do so.

So you got it to run thats good. The two outside cylinders, 1-4 run off of 1 coil, and the inside 2-3 the other. Also the same is true for the Ignition pick up coils. One coil for the 1-4 and another for 2-3. So if spark is weaker on one coil, fist make sure the Plus are not fouled. Swap them or replace them. Then if it is still weaker, try swapping the coils around and see if it moves or stays the same. If it moves then either the coils, wires, or end caps are at fault. Getting new coils and wires would be best if you can afford it.
If it still is weak on the same two plug, after the swap, you'll then need to check the pick up coils, connections at the Ignitor, and wiring before replacing much else.

Awesome, sounds like new coils is the way to go. I'll still do the check, but I've been meaning upgrade anyway. Problem is, Z1 is out of stock (has been for awhile) on the 3 ohm coils. Any other recommended parts sites?

freakinbike wrote: Awesome, sounds like new coils is the way to go. I'll still do the check, but I've been meaning upgrade anyway. Problem is, Z1 is out of stock (has been for awhile) on the 3 ohm coils. Any other recommended parts sites?

:huh:
Z1E's listing says In Stock .

www.z1enterprises.com/ItemDetails.aspx?i...9+DC1-1&item=DYDC1-1

www.z1enterprises.com/ItemDetails.aspx?i...&item=DYDC1-1-single

Good Fortune!