Bike hasn't driven right ever since I got it.

Its a 1994 CBR 600 F2


When I start my bike, it usually takes me 5 to 10 min just to start it. I crank it over for around 5 seconds then let it sit for bit, my battery usually dies before this f**king thing starts. Then when it does start (with the choke fully on) it surges real bad like I have a vac leak. RPM's go from 800ish to 3,000.

I have completely pulled the carb off and cleaned everything EXCEPT the pilot jets (i believe that is the one I need the special tool for)

Then once its fully warmed up I have to have the choke on around 1/2 to 3/4 to keep the bike running and this is with my idle set all the way up. If I touch my header two cylinders will be hot and the other 2 will be luke warm

Today, I pulled the tank and air box off, checked for spark. All have good spark, so I started it up sprayed wd40 in intake ( did 2 at a time) the bike idled perfect at 4,000 rpms (with choke on, just testing the waters) Once we backed off with the wd40 it seemed to idle perfect around 2k but with choke on and idle all the way up.

Put the tank back on and it ran as it usually did.

So my guess is I need to clean my pilot jets, back off 2 or 3 screws or whatever it calls for. Reclean all of carbs with compressed air (haven't used air before) And sync them.

Tonight im going to start it up and spray my carb rubber boot thingys to see if one of the is dryrotted and has a crack of some sort.

Any suggestions???? What gives??

 

sounds like your on the right path. The thing I would have suggested, your going to be doing.

I would think the pilot jets are the problem if everything else is set correctly. If you cleaned the carbs, but had the pilot jets still in place, its highly likely some junk got pushed or blown into the pilot jets. Just tilting the carbs and spraying cleaner in them will blow stuff everywhere and a good chance of plugging up the pilot jets.

Are the carbs synced correctly? A surging engine is a good sign you dont have your carbs synced. Even if they are out just a bit, it will act just the way your describing. It will also create the hot header while the others are warm. What happens is your engine pulses get all messed up. you have one cylinder with more gas going in, the othes have less, the engine fights itself and creates the high and low rev.

 

That sounds exactly like what its doing.

I can get the other 2 to get warm depending on where i spray the wd40

I haven't ever synced these so thats one reason I am leaning towards that. Also, I did install a fuel filter after the cleaning.

Luckily I am taking a motorcycle class at my college. I talked to my teacher about having him help me sync my carbs and he said bring it in that he would help me. They have the tool to get the pilot jets out too. While im at it, im going to do a compression test just to rule that out and to see how f'ed up my cylinders are.

BTW bike has around 15,000 miles on her.

 

Justasquid has it right, clean it up properly with compressed air and remove the mixture screws.

If you ever need to remove those screws and you do not have the tool, pick up some steel brake line for a car and flatten one side of the end of the rod to make it a D shape.

That will match up with the shape on the screw head and you can remove them with the brake line.

 

Thanks hersh.


Anyone else care to chime in???

Hope this fixes it.