Picked up a 95 WVT700 and 96 WaveRaider 1100 that sat a long time. The 1100 had a blown middle piston. I rebuilt the top end, rebuilt carbs, replaced fuel pump diaphragms, checked spark, etc.
Current symptoms:
* VERY hard first start after sitting. Drains almost the whole battery before finally firing.
* Once started, it restarts immediately every time.
* Occasionally coughs/sneezes at idle and loses RPM briefly. Sometimes visible exhaust/vapor in engine bay when this happens.
* At WOT it usually runs great, then randomly just instantly dies like ignition was cut. No gradual bog. Starts immediately afterward and runs fine again.
* Compression: 103 / 110 / 107
* Spark looks good on all cylinders.
* Starter fluid instantly wakes it up.
Only original stuff left is:
* fuel selector/petcock
* some older fuel lines that visually looked newer so I didn’t replace initially.
I’m leaning:
* air leak / fuel drain-back / intermittent fuel starvation
* possible reed issue because of intake sneezing/blowback
But the “starts immediately after first startup” part is throwing me off. Curious if anyone has seen this exact symptom set on Yamaha triples. After the sneeze exhaust does seemingly seep up from out of the engine bay somewhere but only after sneeze.