Kawasaki Ninja 300 Forums banner

1 - 8 of 8 Posts

·
Registered
Joined
·
4 Posts
Discussion Starter · #1 ·
So been having issue with this bike. First it was fine at start of spring riding season. Rode the bike over 75 miles not an issue. Next day rode probably for 45 minutes and shut bike off to chat with friends and all of a sudden bike wouldn't start. Ended up push starting it to get it home. Next day changed out battery for a new one and now we can start the bike but if you let it idle on kickstand for 5 minutes the rpms drop and it stalls out. It will also stall out when in 1st gear trying to take off or downshifting to 1st to come to stop. Does anyone know what could cause this issue cause dealership has no clue. And they priced an ECU for over $500
 

·
Registered
Joined
·
144 Posts
Hmm... It's a 2015, has it sat in a garage for years with bad gas? Does it have fresh gas? How does it sound when you prime the engine before starting, does the fuel pump sound like its struggling? Check the idle when the bike is warm and running, it should be around 1300RPM IIRC. I run mine at 1500rpm, and it is happy. There is a knob on the left side of the bike behind the main side fairing that you should be able to reach that will adjust the idle RPM, but it is only functional when the bike is fully warmed up. The battery issue seems suspicious, maybe it is unrelated... Usually a bad battery won't cause a bad idle or first gear acceleration, it would plague a lot of stuff more of the time I would think. But since you replaced the battery and it starts better, if that keeps working, then it may have just been a bad battery.

If that is all good, I would pull the throttle assembly out and clean it deeply, inside and out. My '14 Throttle assy was spotless inside when I took it out last month, but its often a culprit for struggling idle, because gunk can build up between the butterfly valve and the whole venturi itself. Worth doing regardless if it fixes the problem IMO and is basically free to do. Then I would check injectors. Make sure they look visibly clean, and maybe before pulling all this apart, try a bit of sea foam or injector cleaning product, can't hurt.

Maybe before digging that deep too, check your spark plugs and valve clearance. Mine liked to idle low/weirdly when my valves are out of spec, usually how I know its due other than by miles. Doing those 2 jobs always makes my 300 idle much more steadily and strongly.

The more info you can give us the better! Sorry if I flooded you with a lot of things, just trying to help you out!
-Mike
 

·
Registered
Joined
·
4 Posts
Discussion Starter · #3 ·
So bike is my close friends and she purchased before we could inspect it, big no no for me.. The bike fires right up with no issues. The fuel pump sounds good when you flip the switch. I'm going to put seafoam in today and see what that does. The person said they had it on a tender all winter and said never had issue but yet had stripped seat bolt out somehow. Finally got it removed and battery replaced and that's when idle and 1st gear stalling happened. Bike has 8600 miles on it. Was running good til that issue. Found a lot of issues like this on this forum but they never had issues at start up idle. If you let it idle for longer than 5 minutes it starts stalling out and is hard to get restarted unless you let it sit for a few minutes. I know her boyfriend put 87 fuel in it. I know my 650 likes 91. So going to get the 87 out of it and refill with 91 and some seafoam and see if it helps, also her air filter was nasty looked like it's never been cleaned. Got new one coming in by Friday. Going to replace plugs and check valve clearance Thursday after work. Just never had this issue with any ninja I've owned.
 

·
Registered
Joined
·
332 Posts
I don't have much to add...Sparky is the engine expert, here...but the plugged air filter jumps out at me. Those are foam, reusable, and can be cleaned, reoiled and reused. Wonder if it's as simple as a completely plugged filter? (and a 'never cleaned' filter on a '15 would make me question every other maintenance item on the bike - brake fluid, coolant, oil, chain, lubing and cleaning calipers, etc...)
 

·
Registered
Joined
·
4 Posts
Discussion Starter · #7 ·
I don't have much to add...Sparky is the engine expert, here...but the plugged air filter jumps out at me. Those are foam, reusable, and can be cleaned, reoiled and reused. Wonder if it's as simple as a completely plugged filter? (and a 'never cleaned' filter on a '15 would make me question every other maintenance item on the bike - brake fluid, coolant, oil, chain, lubing and cleaning calipers, etc...)
So update... got it figured out. Her boyfriend for some reason when battery died thought q fuel injected bike had fuel shut off switch and turned a random valve on left side of bike.. well come to find out after my old man told me this, I checked it out and it was the freaking idle control, so I adjusted idle to normal range of 1500 after it started to die down and well now its running smooth as can be. Had already cleaned air filter and that didn't solve problem. But now it's fixed. He isn't allowed to touch bike again 🤣
 

·
Registered
Joined
·
144 Posts
Called the idle adjustment haha.
Glad it's working good, that makes sense, because the high idle for warm up would be active until the engine warms up, and then it would release the throttle slowly to actual idle, and in your case, it was way too low.

It's always something lame, lol.
-Mike
 
1 - 8 of 8 Posts
Top