My bike was dead all last summer so this winter I decided to work on it and actually get to ride it this year.

Symptoms of not starting-
1. It will start but couldn't hold the engine running.
2. It'll die but if I crank it for a bit it'll backfire and just keep cranking.
3. It'll start, but I'll have to rev the crap out of it to keep it alive and once off throttle it'll just die instantly.

What I did this week, (March 20th)
1. Took off the carbs, and cleaned it inside out, jets, etc etc etc. Air hosed all of the hoses and fuel holes in the carbs.
2. Changed out spark plugs to new ones.
3. TESTED for spark on each individual spark plug wire (Seem like the spark was just tiny and small, but maybe the bike just needed a small small spark.)
4. It's getting fuel because after each crank I drain the bowls, and theres fuel in each.



WHY isn't it starting? Any ideas? Thanks. Anything will be appreciated.


Trouble starting 1998 CBR F3 - YouTube

 

I got the bike to some what crank over with the use of starting fluid. It wouldn't stay alive though,.

From sitting on the bike.
It's cylinder 1 2 3 4.
The left spark coil goes to 2, 3 cylinder
And the right coil goes to 1, 4 cyclinder

Correct?

 

Just checked the wiring diagram in the service manual. It looks like it goes 1,2 and then 3,4.

 

Hey I had the same problem. the correct diagram for the spark plugs is 2,3 and 1, 4. The way mine was set up was 1,2 and 3,4 which would make it start with starter fluid but backfire when rpms dropped. What I would try, and dont quote me on this, but turn your idle screw up, about 5-10 turns and keep trying that over and over with starter fluid. Now this could be wrong, but its what i did to get mine running and it eventually worked. If that doesnt work, it may be the valves.

 

Clutch not required to start?..... I learn something new every time I check this forum :-)

 

You know, my bike was set up as 12, 34 also, but according to the books its 23 14.


And i've messed with idle screw and still wont budge. It only starts when I spray starting fluid into the carbs while attempting to start. It doesn't fully start but it'll fire then die within 5 seconds. I'm confused, might just take it into a shop and pay a bill.

 

I realize that you might not like/want to hear this, but I'll bet that your carburetors are still not clean. The fact that it will fire with starting fluid indicates spark is good. Now, I would verify that you've got the plug wires hooked to the correct coil and plug. Look closely at the wires, you notice that they are numbered so you know what plug they go on. Then it's a matter of making sure it's plugged into the correct coil.

As for the carburetors, having fuel in the bowls is good, but doesn't mean it's getting to the engine. Sometimes it's hard to realize how small the passageways are inside the carburetors, and how small a blockage can be. Having a bike sit for the better part of a year with fuel in it can make for a difficult cleaning job. Trust me, I've been there. It took me 3 times to get one set of carbs clean that I let sit for a year.

Take a look through this thread and see if it helps you with making sure your carburetors are clean.
https://cbrforum.com/forum/stickies-...cation-124026/

 

Yeah that's what I was thinking and hearing people say. I think I'll take them off again the week, and bring it to a friend to do some deep cleaning! Thanks for the reply! Very helpful!

 

Agreed that carbs need to cleaned. They will need to be disassembled down to each individual carb and then dipped in carb cleaning solution. The jets, needles, and other components should be dipped too. While doing this, you'll most likely have to replace the o-rings too.