Hi. Traded a bottle of whiskey for a zxr250 (1991). Bike's been sitting for 10 or so years. Already stripped top end to inspect cylinders, look fine. No scratching etc. Did oil change, new filter. New plugs. Good spark. Carbs were (supposedly) professionally rebuilt and never put back on. Carb boots look fine, no obvious cracking (taken off and inspected) Fuel running from aux tank into carbs. Timing has been redone. Won't fire. Not even a single pop. Have tried using starting fluid (ether). All 4 cylinders have spark. Have tried pouring a bit of oil into cylinder and tried then. Nothing. Side stand up, clutch in, bike in neutral. Engine turns smoothly. Using large boat battery with good voltage (12.8) to crank. Dumbfounded. Any ideas? Thanks. Want to get it running so i can sell and fund my MC22 project which i plan to keep.
They were rebuilt and never had any fuel put back in them. I just checked the bowls and they're clean.
Leads in the right order? https://www.2fiftycc.com/index.php?...eads-spark-plug-configuration-inline-4s.8176/
Also, the trigger wires (black and green, red is common power) need to be on the right coil, which I assume Grey was also alluding to in the leads/coil arrangement.
I stripped the top end and put it back together after i couldn't get it to start the first time - was checking valves
All i can think is that for some reason the plugs might not be sparking inside the cylinders. Not sure how/why. Everything else checks out.
Even if the plugs aren't firing, you should still get something from the compression of the easy-start spray. Is it possible that engine has no compression?
Definitely possible on a bike that was sitting for 10+ years. I didn't notice anything off though, no corrosion inside the cylinders etc. According to previous owner it was running before he parked it. I've tried pouring some oil down the cylinders to see if that helps and it didn't. The compression tester that i have doesn't have a fitting that fits the spark holes.
Oil should have raised the compression, but might not help with combustion. I'd find a motorcycle compression tester and be sure of what you're working with. It sounds like the rings might have seized in the 10 years it has been sitting. You've rebuilt the top end, so all valves must be seating properly. You've rebuilt the carbs so you know fuel is flowing. Not much else that it could be?
Stick a finger over the plug hole while cranking the engine on the starter. The compression should blow your finger off the hole. If it doesn't then you need to find why.