Honda CBR 300 Forum banner

1 - 9 of 9 Posts

·
Registered
Joined
·
5 Posts
Discussion Starter #1
I have been having an issue getting my bike started the last 2 weeks or so where it cranks for a long time but doesn't always start. This happens almost every time I try to start it after work, which is only part time so it sits for 4 to 6 hours .

It starts okay after sitting overnight in my garage and I am leaving for work though. It also idles fine at 1400 and runs just fine once it starts.


I put a new battery and spark plug in it and have run seafoam and an stp fuel cleaner through and still having this issue. I read the troubleshooting in the manual and it states if it doesn't start to try opening the throttle fully and press the start button for 5 seconds and try the normal starting sequence again. ( The manual states it will not start with the throttle fully open.)

So far this has worked the last 4 times I tried and it fired up instantly after I did this but the manual doesn't say what the problem could be or why that is necessary. Has anyone had this same issue or know what opening the throttle fully while holding the start button is doing?
 

·
Premium Member
Joined
·
5,373 Posts
The throttle full open method allows maximum air to flow through the engine and is a trick used for clearing a flooded engine of excess fuel.
It makes me wonder if your engine is running rich. What is the colour of the exit hole of your exhaust? What was the colour of the tip of the spark plug you replaced?
I would be inclined to start with checking your air filter. If it looks dirty replace it.
 

·
Registered
Joined
·
5 Posts
Discussion Starter #3
I have a K&N air filter, I just cleaned it but it didn't seem very dirty. Waiting on it to dry so I can re oil and install it. The exhaust is just black pretty much everywhere near the exit. I took a picture of the spark plug, I'm not sure what they are supposed to look like however so not sure if it was really that bad or not but I had about 15k miles on it so figured it needed to be replaced anyways.
34812
 

·
Premium Member
Joined
·
5,373 Posts
The very tip of your plug seems overly white which indicates its been running hot and lean. Ideally you want a light tan color but manufacturers are setting bikes up to run quite lean stock now so that they pass stricter emission standards and achieve better fuel economy. So there could be something in that or not. Surprised to hear your exhaust exit is black though. The two don't match. Are you doing mostly city commuting as this will make the pipe blacker?
 

·
Registered
Joined
·
5 Posts
Discussion Starter #6
Just a quick update, it's starting better now but having another issue. Before it wasn't starting after holding the start button so I would eventually let go and wait for the battery voltage to go back up before trying again. I did that earlier and it started after I let go and was about to wait. I tried to start it again and it still just cranked and as I let go the bike started.

I am now able to start it every time but only after the start button is released, I used some contact cleaner on the start button contact and still no change. Could this be a bad contact somewhere else or a short?
 

·
Premium Member
Joined
·
5,373 Posts
Electrics aren't my forte but there was a re-call on the starter relay under the seat back a few years ago. What year is your bike?
 

·
Premium Member
Joined
·
5,373 Posts
My 2015 was recalled for starter relay. Maybe fixed by 2016.
See how it goes, might come right.
 
1 - 9 of 9 Posts
Top