Hey guys,

So I was looking around the forums trying to find someone with the same problem as me, and I couldn't quite find a match so I thought I'd start a new thread.

Basically, I bought a 1996 CBR 600 F3 about three weeks go. About two weeks ago I took all the fairings off and painted them, and at the same time I changed the oil in the bike.

Before and after I had ridden the bike short distances to see how it ran (1-2 miles - city) and it was fine. This morning I got my endorsement on my license and wanted to go for a real ride. The bike started normal and idled fine. I rode about a mile and in third gear at about 45 miles an hour (4-5k rpms I think*), the bike began to bog down and couldn't keep a constant speed. As I fed it more throttle it got worse and when I pulled the clutch in to stop the engine died.

Here's where it got weird. When I went to start it back up it wouldn't turn over. When I turned the choke up I had to have it all the way up and even then when the engine started it would rev to +7k rpms and when I tried to take the choke back a bit, the engine would just die again.

I left it for like ten minutes then tried again. It started, but after about 1 more mile on the way back home, it all happened all over again. I ended up walking the bike home and now it's in my garage waiting to run again!!

Plugs? Fuel Filter? Carbs? Air Intake? Idk.
Any ideas?

 

It sounds like fuel starvation for some reason. Fuel pump, filter, kinked line, clogged petcock screen... it could be any number of things. It doesn't sound like plugs or air restriction.

Did you have the tank off? If so, make sure your fuel line is not kinked. Also, there is a tank vent line that needs to be open. If it is kinked or blocked, the bike will run until gas can no longer flow. An easy way to check this is to run the bike until it stalls. As soon as it does, open the gas tank cap and listen for a suction noise. If there is a noise, you have a plugged vent line. The vent line should be hanging down around the middle of the bike.

 

Number One Check the Fuel pump, its a common problem throughout honda bikes. The fuel pump slowly starts to die out and the fuel pressure is either not high enough or in the higher RPMS it is not getting the fuel needed.

Number Two if you put to much oil in the bike when you changed the oil your looking at starvation for air. The oil will overflow into the airbox and gum your filter up. If you put to much oil in the bike you may have also fouled the plugs and whipped the oil, new plugs, and new oil change, might wanna get a new air filter as well. Hopefully this is not the case but seeing you didnt ride it very far you shouldnt have to worry about blown seals, gaskets, or rings.

Check the fuel pump first i would bet my money on that

 

Whenever my F3 acts up first thing I do is put my finger on the fuel pump while its running or while im trying to start it.

You will either feel nothing in which case you should find the thread on here about how to replace the contacts on your fuel pump, I tried sanding mine down and paid the price 2 hours away from my house when they failed me and a buddy of mine had to come get me with his trailer.

You will feel a slight throb every once in a while which means that the fuel pump is working properly and the issue is somewhere else.

Or you will feel it throbbing rapidly which means that the fuel system is starved of gas so maybe your filter or your petcock are clogging it up.

Edit: Also some people will never use it but it doesnt hurt to pour some Seafoam in your gas and run it for a bit. This has worked for me a few times and saved me from pulling and cleaning the carbs. But ps i think every F3 owner should clean their carbs at least once just so you can know you started on a clean slate. I cleaned my carbs the summer I bought my bike after having some issues and now I always use 93 octane fuel and put seafoam in the first fillup of the year and my carbs havent given me a fuss since.

 

Before you blame the fuel pump, check the regulator/rectifier.
When they first start to fail, as it heats up you'll lose spark, then it cools down,
everythings fine...heats up, problems, cools down it's fine...

Look at the r/r for any signs of heat-related damage...warped/melted harness connector,
cracked/bubbly epoxy fill on the r/r, melted wiring.

Here's a link that doesn't require anything but time and a multi-meter to check it out....

Charging System Diagnostics - Rectifier/Regulator Upgrade - Triumph Forum: Triumph Rat Motorcycle Forums

Good luck, Ern