Hello everyone, I'm new here and I'm helping a friend of mine work on his CBR600. it was running just fine. Then it was stolen. He got it back and the ignition switch was ripped out of it and the starter button was changed for some reason. Also the people stole the fuel pump off of the bike. Kinda crazy, looked like they were getting ready to part it out. But when they stole it they rode it because they had the ignition modified with alligator clips and a resister like they knew exactly what they were doing.

So, he ordered an ignition switch and a set of right hand controls for the bike, and then the fuel pump as well. So at this point we have spark (I checked it) we have fuel, (brand new fuel pump and it is pumping.) And the bike cranks and has the occasional pop like it's trying to start but it just wont. I'm at a loss as to where to go from here beyond doing a compression test and seeing if the people who took it hurt the motor somehow. Is there some kinda finiky stuff about these bikes that I'm not aware of? I'm a Kawi guy and I have a very heavily modified ZRX1200, that I built my own fuel injection for. So I'm pretty familiar on how to get stuff running, but this has me baffled. I dont see anything obvious that should prevent it from running at this point beyond something internal being wrong.

Unless, there is some kind of finiky stuff that they could have screwed up in the process.

 

Those guys definitely had done their homework or stolen an F4 before. If you have spark at all plugs I’m gonna assume the ignition diode is good and the CDI is seeing the 9v on the pink wire.. so that’s one finicky issue seemingly resolved. Fuel in the bowls? Plugs wet? Coil plug connectors in the right order?Just want to make sure fuel is getting down to the carbs and everything else is right..try running it straight off a bottle first. I know when I rebuilt mine it took a while for the fuel to make it to the bowls before I just ran it straight off a bottle. If it’s trying to pop I’d guess it has compression. Will it try to run off carb cleaner?

 

Yes, they did, they knew exactly how to steal it, I think these people were stealing them and parting them out. I verified spark to all plugs before, but I am going to do it again. At first I didn't have spark at all. But I learned about the resistor and got the spark going. I know it's getting fuel because there is fuel vapor coming out of the exhaust, with the occasional backfire. I'm really hoping they didn't hurt the motor when they stole it. I'll find out this coming weekend whenever I go back up there with my compression tester.

 

Seems to me that’s the big part of the equation missing. These bikes will absolutely rip and still can hang, for the most part, with a modern 600.. my buddy has a 600RR and 0-120 I usually have the faster bike, where his seems to have the advantage on the top end.. but I’m saying that, the F4 is super simple. If you have spark and fuel.. it should try to run even if it runs like crap. You seem to know your stuff so.. not saying anything you don’t already know. If you’re testing compression and getting the air box off to get to the plugs I’d try starting fluid to see if it’ll try to run.. if not.. they had more fun than they should’ve gotten away with.

 

Yea, that's what I thought, I mean things with carbs are easy to make run, as long as all the elements exist. My zrx was that way too, super easy to make run. Now, if something isn't working, I have a lot more things to look at

 

That’s for sure, we’ll hopefully there isn’t a trip down the rabbit hole waiting for you guys. I know when I got mine and restored it, I got it as a frame and engine and had plenty of gremlins to chase... but after it all it’s an awesome bike, smooth but can bring it when you want it to. Let me know what you guys figure out. I’m a motorcycle technician by trade so I’m curious myself. Oh here’s mine before and after. Just got it done about a month ago so I’m still showing it off

Before

After

 

hello my name is justin i have a 2000 honda cbr 600F4 carburated i am having trouble with it starting it turns over good and theres no fuel priming thru the fuel pump theres fuel in the fuel filter but i took the tube off the gas tank n none of the fuel primed in to the fuel pump but it is wanting to start it does sputter over or sound like its trying to start i dont know if it is the fuel relay switch or solenoid.

 

Have you tried to see if it’ll run off of a bottle? When’s the last time it ran? Have you tried to jump the connector at the fuel pump relay to make sure the pump is able to run?