Issues starting the bike (for a noob!)

[Chef.tyrone]

Hello all! Total noob here.

I’ve recently started working on an abandoned 250R, branching into the world of motorcycles and mechanics. I have virtually zero experience beyond what I’ve learned from YouTube, and am looking for some pointers on where to go from here.

After a few hours of replacing the spark plugs and batteries, I was able to get the thing running, but the engine would only stay running at high RPM’s and wouldn’t idle without shutting off. After replacing the air filter (it was disgustingly dirty) and having someone clean and reinstall the carbs, I’m now trying to reassemble everything, and the bike won’t start.

With the key in, the dash lights will turn on, but the bike won’t crank over or start at all. The battery/bike were sitting dissembled in my garage for two months, and I’m wondering where the issue might be. Is this the right forum for these questions? I could just take it into a shop and tell them to let me know when it’s figured out, but I’m trying to balance this being a learning experience with me not quitting out of ineptitude and frustration.

Thanks in advance yall!!

[Bob KellyIII]

Sounds like there is no fire getting to the plugs.... so is the kill switch on the right side handle bar in the RUN position ? if it's not it will do exactly that !
it will crank but not start....
if it is then perhaps a fuze has been blown
....
and another word of warning here is needed... these carbs are the hardest to clean of any motorcycle I have ever owned and I had a motorcycle shop !
I cleaned them 3 times before I finally got it to run it took completely dissembling the carbs and using long cleaning probes to get into the pilot circuit
and a whole bunch of carb cleaner..... and after all that.... it still wasn't perfect
so I sent them to Ducattiman and had him clean them and fix everything that was wrong.... and he FOUND some problems ! these are tough carbs !
it's probably not running because the pilot curcuit is plugged... and that circuit is very hard to clean out correctly...it takes a ultrasonic cleaner and soda blasting to do it right !
.... simply pull off the carbs and send them to Ducattiman, Gordon will fix them and you won't have to fight them like I did !
just give him a PM and he will give you the details.
....
an engine needs Spark compression and ignition and they have to be in the right order and it Will run
finding out what it's not getting is the hard part.... check each of those 3 things and make sure it's getting spark.... make sure it's getting fuel
even if you just use quick start down the throat of the carb....
the compression we can assume it is ok because you did have it running earlier... now it won't start.... so spark and fuel.... start there.
....
Bob......

[Triple Jim]

How old is the battery? Try measuring the battery voltage at its terminals when you turn on the key, and when you hit the start button.

[Bob KellyIII]

Good point Jim !
I remember trying to start my Ninja just after I bought it and it would crank for 10 minutes if i wanted it too but it would not fire...
I looked in the manual and found that the ignition system would not fire if the voltage fell below 10 volts.... I pulled the battery and charged it and it immediately fired up the next time I tried it.... so lesson learned.... learn from my mistake... if it doesn't fire up relitively fast stop cranking it as all that does is drain the battery more. the battery has to be a good one ...when you add the starter motor to the equation it usually will draw down the voltage far enough to stop the ignition from working... so it's time to charge the battery again....

that is what Jim means by saying check the voltage before and when cranking
because many times that voltage will drop below the voltage threshold and the bike will get no fire to the spark plugs... so your wasting your time...
...
Bob......