Got a 1999 Yam 40 2 stroke 3 cyl. Had carbs cleaned early march. Ran/idled fine for few time out. Sat for a while and ran some older gas thru her not too long ago (2-3 month old gas). Made a new tank up today of 50:1 6 gals and she still want to die at idle. Almost like it is missing..... rev a little above idle and its fine. Last time it did this the top (1st?) plug was foulded bad. Also the plugs are new NGK's. Any ideas. No I did not check the plugs when I put it up today. But will check here soon.