'86 Spree starts/runs, dies at 15 mph

[btruitt3]

I just bought an '86 spree within the past week and was told by the prior owner that the oil strainer could probably use a cleaning. Before I cleaned it, the scooter ran okay (could be improved a little) and the oil light was flashing. So I cleaned the oil strainer and air filter in accordance to the owner's manual. Drained, bled, and replaced the oil with a full synthetic 2 stroke racing oil recommended by a local scooter retailer. It actually starts up a little better and idles seemingly well, but power drops off at about 12-15 mph and actually cut off on me twice. I didn't tamper with it long after that, as I was afraid that continued use might cause permanent damage. I obviously want to fix it, and soon since it's my mode of transportation to school this year, but I'm not quite sure where to go from here.

I would greatly appreciate any advice/guidance on this situation.

[scooternewby]

Sounds like a carburetor issue, or possibly a spark plug issue. Maybe do a plug chop, see how it looks.

[btruitt3]

Checked spark plug and re-cleaned carb (soaked overnight, blown-dried, and air-dried) and problem remains persistent. I've noticed that when I try to accelerate it will do so effectively and drop back off to idle while i continue to hold the throttle; eventually revving back up.

I have two things in mind at this point:

1.) The prior owner didn't actually run a full synthetic as they had claimed and adjustments are necessary to do so (although I wouldn't imagine the effects to be so drastic).

2.) I did not bleed the oil effectively in reassembly after cleaning the oil strainer.

Any tips or scenarios that could play off either/both of these two ideas?
Also, tips on insuring the oil bleeds effectively?

[veithouse]

I had a similar problem, ran good til about half throttle then mudded out. It was the ignition coil. Swapped it with a different one, and got to full speed. If you have an extra one its worth a try.

[btruitt3]

I thought I had the problem worked out. I re-bled the oil and had it running really well all day yesterday. Then, last night I made a run downtown and about 3.4 miles later it went back to its old habits. Just like you said, mudding out at about half throttle. This time it died and left me stranded in the middle Atlanta. After pushing it about 3 miles I was able to get it started back up, running along side and jumping on as I got enough speed (had to restart it a couple times actually). Whenever it bogged down I would slightly pull the rear brake and it sufficed long enough to get back home. Already ordered an ignition coil, however, I wanted to see if there were any other culprits in mind?

I really need this spree to be as reliable as a 1986 model can be.

Thanks