Need Help Please
 

Hello,
I have been reading this forum for about a month since i got my first Cane. An 89 cbr 600 ( I believe California emission version, eventhough i live in Ohio). I have a slight knowledge of motorcycle and been using that to do preventive mainenance and slight modifications with my bike. So far I have flushed and replaced all fluids, and a custom modified rear-end project, and pulled the carbon canister and all vacuum line and didnt plug any of the holes. This weekend i planned on doing a new stock 15 sprocket in the front, a +2 sprocket in the rear with a new DID chain and have the rear tire replaced in the process. However i decided to change out the spark plugs to new NGK Iridium plugs, and replace the fuel filter earlier today. So now onto the problem.

I removed the seat, the tank, the airbox. all the way down to the silver plate that sits ontop of the carbs. Well after i got the airbox off. I pulled the vacuum lines from the back of the airbox and continued to pull them off after where they T into on then connects to the top of the engine. Reason being I was reminded of a pcv valve on a car and believed I did not need this, at this point i also located a large vacuum line in the same area that connects to the mechanism on the front of the engine that has 4 lines feeding to above the exhaust ports on the engine and have no idea where this connects to or what it does. Continued to change out the plugs with NGK Iridium plus. Then made a decision to drill out the airbox with somewhere around 15 1" holes and noticed i had a K &N air filter. I reassembled without the T thing that connects to the airbox and the top of the engine, and the very large vacuum line from the same area.

I took the bike out for a test run and noticed it had a much deeper growl. However, the bike has no "balls". It will go, but only at about scooter speed. IT seems to smoothly go through rpm's but is just extremely slow about it. I took it back and reassembled and made many changes to find the problem trying to eliminate everything I did to narrow the problem.

Put old plugs back in and check them and new against ground while cranking engine, all new plugs had spark. Ran bike with duct tape over holes in airbox and still now real power. Hooked back up the T vacuum lines to airbox and top of engine. Would have tried hooking back up Large vacuum line but unsure of location. I plugged the line because made very loud vacuum sound while riding. Still no power with large vacuum line plugged. After i put all of these back to stock (with exception of large vacuum line because unsure of true location) the bike still has no power. If anyone has any suggestion they would be extremely helpful!

Also noticed the air/fuel mixture screw on the left side carbs seems to be stripped. Any suggestion on how to fix this? Finally any suggestions/ how-to's on changing both sprockets and the chain?

I would appreciate any help i am completely lost and this is my main form of transportation for work. Please help!

Hi bro get some info/ pics on what your air and fuel induction systems should be like. try the manual for download on here and also parts websites for diagrams. have you pulled the plugs to see how the fuel is burning? I suspect your running really rich and not getting enough oxygen in cylinders due to that big vacuum line not being connected. put a vid on youtube and have a look at "mrmaxstorey" on youtube, you could even ask him for ideas. His vids are awesome. Sorry if i'm suggesting stuff you already know or is vague.
gud luck man

dodger79,

I appreciate the response. I was very stressed out over this situation the other night and am only an amateur when it comes to wrenching on bikes so i was lost. I searched this forum and to my surprise and humiliation i found a diagram that outlines the spark plug wires and someone explaining similar problems to the one I was having. Immediately upon seeing the diagram I realized i switched the plug wires for the 3rd and 4th cylinder and ran out, switched them, then hopped on, and the bike had full power.

Since then i have replaced both sprockets on the bike with a +2 on the rear and a stock size on the front. Also replaced with a DID chain stock length. After completing this I hoped on the bike and took off to see if there was much of a difference in acceleration. The bike did not produce much of a difference in acceleration but rode MUCH smoother. However I did notice the bike had a weird ticking noise coming from the front of the bike(that only occurred when i accelerated, never while cruising or deceleration). Almost like something was stuck in the front tire. It would also sometimes make a popping noise when i shifted. The tire was free of debris and seemed to run fine so i ran it for a couple days like this. I finally came to the idea that it was an exhaust leak (of which occurred from pulling the exhaust to get the rear caliper off while changing the sprockets). Today i pulled the exhaust back off and replaced the studs and nuts and hooked the exhaust back up and no more noise.

I am finally left with currently 2 problems on the bike. When i was having problems with the bike having no power, I tried adjusting the air/fuel mixture screw (which i was told is a tiny screw on the outside of each of the outside carbs (correct me if i am wrong)). Well the screw that controls the air/fuel mixture for cylinders 1 & 2, appears to be stripped out. If anyone has any suggestions on how to fix this i would greatly appreciate it.

Second new problem. While changing the sprockets the bike tipped over off of the jack stands and landed on the clutch cover of the engine and cracked the bottom side of the cover. I used some putty for a temporary fix to stop the oil from leaking out. It has sealed the leak but it really annoys me and i would like to get a permanent fix. Has anyone had any experience with getting this welded shut or would i be better off just buying a replacement cover off of ebay with a new gasket?

Finally when doing my custom fender eliminator. I now have for sale a black plastic fender piece and the little back fairing that rests behind the seat (grey in color) both brackets are broke off this fairing but rest appears in decent shape. Figured i would offer on here before put on ebay. I live in Northwest Ohio if anyone is interested.

Thanks!

The california model bikes (not sure about 49-state models) have limiting caps over the carb mixture adjustment screws. The screws should have a standard slot adjustment screw when the caps are removed. If the caps are already pulled off you'll have to find another method of turning the screws or replace the carb or mixture screw.

My advice is to pull and clean the carbs if necessary, set the mixture to factory settings, and once it is running perform the sync procedure. The service manual covers all these procedures in detail.

As far as the cover it can be welded, but it might be cheaper to buy a new part. They come up on ebay for a reasonable price occasionally. If it's welded properly it should be fine, but you'll still be able to tell that it was damaged visually.