Join Date: Feb 2018
Location: Belgium/Austria/Czech Republic
Stalling after short rides
I was finally able to wake up the GPZ from its hibernation this weekend.
Problem was she wouldn't start. The cranks were blocked, so I assumed the engine was flooded (for whatever reason). Unscrewed the spark plugs, cranked and blew out the gasoline (a lot!).
Started the engine and let it idle for around 15 minutes (was burning some oil). No problems there, nice and smooth idling, only needed choke for the first 10 seconds or so.
Put on my gear and went for a ride. She was riding very well for around 5 km or so, good throttle response, no lagging etc. Then suddenly, the throttle went dead, typical "no gas" feeling. Switched on the reserve to be sure, but I knew she had gas left. Didn't help, engine stalled while waiting at a red light one km or so down the road (throttle response getting worse and worse between the first symptom and the eventual stall).
For some reason she wasn't getting any fuel. I left the bike there and continued the ride on the back of a friend's bike (we were going somewhere). Came back around 3 hours later with a full jerry can of gas. Tried to start her before doing anything else and she was up and running at the first crank.
So somehow, I guess the float bowl filled up through some kind of leak or something (?) and the engine had some gas to burn again. Drove it back home and stalled in front of the house (so pretty much the exact same distance). Same thing, starving engine.
I took off the tank, and screwed out the petcock. Tested the functionality (funny image, me sucking on the fuel line and my buddy sucking on the vacuum port) and as far as I could tell, it was totally fine.
I would assume the petcock is not getting vacuum from the carb?
What about this leaking, that it stands for a while and I guess fills up the carb float bowl so I can ride for a short distance?
Why did the gas flood into the engine like that over the winter?
Was thinking I could remove the spring from the little rubber petcock valve to check if it really is the vacuum?
I am quite sure it is some small/stupid/easy to overlook problem...
Grateful for any suggestions/help.
GPZ 500 1992 (EX500C1)