1985 NQ50 refuses to cooperate!

[Anson3]

Wow, I am really glad that this forum exists! I'm at wits end...

I have owned a 1985 Spree for about 5 years. IT USED TO RUN faithfully. I have over the last year:

Replaced the reed valves and gaskets
Rebuilt the carburetor
Replaced the auto by-starter with a new one
Replaced the fuel valve with a new one
Drained the fuel tank and added fresh gas
Replaced air filter
Oil in tank and oil in combustion(visually)
I DO own a maintenance manual and use it

It has good spark and will start and run at a a high idle but faulters when asked to run above idle. Itsfrustrating because it will start and sometimes run for several minutes and I can actually ride it but then eventually bogs and dies and will not start afterwards. I have tried this with the gas cap removed and am getting positive fuel flow, as far as I can tell. Not sure if I have low vacuum which is closing the fuel valve? The spark plug is usually wet when removed after running. Its as if it is too rich but the exhaust seems to be normal 2 stroke smoke. Have not measured vacuum. ANY IDEAS ANYONE? I don't want to throw anymore parts at it. Believe it or not, I am an aircraft mechanic and maintain two piston twins and a business jet but can't get past this scooter!! HELP!

Thanks very much for ANY input.

[Anson3]

By the way, when I pulled the oil injector hose off of the carb base I expected to find oil spewing under pressure (with engine idling) but no oil was flowing. Is this normal? Is the oil pump low displacement or perhaps failed?

[CharlotteSpreeRider]

Replace the oil and gas lines with Tygon, so you can actually SEE what is happening with the gas and oil. The oil is not under pressure, at idle, only a drop or two should come out into the intake manifold every 10 seconds or so.

-aseigler

[Anson3]

Excellent idea. I like your other replies to these topics and hope I can get this thing sorted out. I just pulled the side case and felt the compression by rotating the drive pulley and it feels healthy. I need to get a compression tester now that I can't find the one I have. Anyway, please keep the suggestions coming!

Anson