1990 FL intermittent starting issue
 

Hi all

About a month ago I bought a 1990 FL CBR600. It ran really well when I picked it up, but since then it's developed a really annoying and intermittent issue.

Basically, one time out of twenty it just won't start. You press the starter button and you can hear the starter motor, but the engine simply will not fire. The only way to get around this is to find a hill and bump start it. It bumps very easily, and as soon as it starts, it runs perfectly for another week or so.

The first time I had a problem with it was after a two hour motorway ride, when it did get pretty wet. When I came to start it again after that, it did eventually start using the starter button, but it ran very poorly. I took it to a petrol station and filled it up, and it just wouldn't start on the forecourt. That's the first time I had to bump it, and it's been quite a regular occurrence since.

Any thoughts more than welcome!

Are you running stock air box and stock filter?

If you are and you're having problems especially with moisture, I'd say it's most likely something electrical.

What do you coils look like? What does the wiring look like? Have you tested your battery?

Could be a lot of things but I would start with checking battery first. Check the voltage both static and running...

i'm having a similar issue with mine, battery voltage is around 12.6 resting, you try to start and it cranks and cranks forever, bump start once and it starts right away. If I can come up with something I'll be sure to post here.

my CBR had a hot start issue for a few months that I just fixed last week. Anytime the bike had been running for more than 5 minutes my starter would just crank and crank. (would bump start every time though) This was reeking havoc on my battery, for some reason it seemed to drain my battery faster. Anyways, I tried replacing the starter brushes and I immediately noticed a much faster cranking RPM, but still I had a hot starting problem. After testing every single component of the starting circuit; every switch, every wire, resistance through the solenoid, I decided to buy another starter completely. I swapped over the new starter brushes to the 'new' starter, and she fires up every time now. my bike has not been this reliable for awhile now.