Hello, my 87 CBR is having some issues. When i start it, it will run fine and idle. Then after a min or 2 the guages will start going crazzy flopping up and down all the way, and if i try to give it gas, it bogs down. Then it will die. I can start it again after a couple min and sometimes it might be fine, then others the same thing. Happened all day sat. This summer i had the valves adjusted, carbs cleaned/sinked, and some other odds and ins. Any ideas on what would cause this? Help would be nice. If i cant get it figured out come spring, the bike will be for sale. Runs great when it runs. Has new tires, and is in real good shape. We will get to that later. for now, would like to figure it out if i can. Thanks for any help that can be provided..

Paul

 

Sounds like an electrical problem. (FUN). More exact.......it sounds like a bad ground somewhere. Check the battery leads and make sure they are clean and tight.What gauges are jumping? The Speedo is driven off the wheel so........that shouldnt move. The tach however is electronic. That and the temp gauge jump around?
Somewhere you have a bad connection (likely).
Start with that......and start at the battery.

 

Dont those have a fuel pump? Perhaps a bad connection on that? That would allow fuel to not flow at times (so when you give it gas it has too much air.....not enough fuel.....and it dies)

 

Thanks. Yes, it is the Tach and the temp that jump. I wondered about electrical. I had taken it in a fe wmonths back and they said a wire was melted at the starter. Maybe they didnt get thing hooked up right, or tight. I will have to tear it apart and check all wires. Winter project i guess. Also suspected this because my brand new battery with a full charge in the bike was dead after 2 weeks of sitting in the garage. Figured it would take longer than that to drain it by sitting? Unless something on the bike isnt right. Thanks again for the help. If anyone else has other suggestions, keepem coming, Might as well make a list to check. Thanks

 

Electrical problems SUCK to track down. Thankfully your bike doesnt have much on it yet in the way of electronics. Your battery should not die that fast. I've not had to replace a battery on a bike yet. No tender on it.....I start it and let it get thoroughly warm and ride it at least 6 blocks every month. (there is always ONE nice day in a month) and have not had one problem with mine. That is durning the winter......in the summer obviously there is no problems.
Is the Rectifier/Regulator ok? A bad one will ruin a good battery FAST!! And, it will cause your bike to not run very good at all. No wires should be melting. If they are....they are likely shorting out somewhere. Check the starter wire again.

 

What happened was i took it in for the valve work. Got the bike back and it was running badly. I took it back to the place that worked on it, and they said a wire had touched something hot somewhere causing the charging system not to work. So the bike would die when the battery ran dead. They said it wasnt chargin my battery. That was why it was doing what it was doing. I noticed a huge difference in the brightness of my lights. It seemed to be fine. Then this started happening to me. I guess i will just have to tear it apart and check all wires. Just threw me off since the battery went dead while the bike was sitting. Wasnt started, no key in it or anything. Looks like i have a project then...

 

Whoa...........the lights thing. A huge difference in what? Were they REALLY bright?

 

Yeah, they were much brighter. The guage lights were brighter too.. Why, whats up?

 

Your rectifier is shot. It feeds the battery (among other electrical fun). We fought a freinds R6 doing this for a LONG time. He had just bought an aftermarket one (to replace a bad one)so we figured it was ok. No, it was bad. He bought an OEM Rectifier and it was fine. It chewed up batteries like they were candy. AND......his lights were all WAY bright. It was overcharging the whole system. Put the OEM on it and have not since had any problems. But.....it did everything you describe.
Somehow yours got shorted out. If you put a new one onit you will likely not experience any problems anymore.
Essentially it is overcharging so hard that it will boil the fluid in your battery and destroy it. If you just let it sit......your battery would have been fine, it was the riding it that killed it (in this case).
Your local shop should be able to hook you up with a new one.

 

I will try that. I might have fried it myself. A while back i was dumb and took my Solo seat cowl off before i took it to the shop. The person before me put aftermarket turns on the back. Didnt seal the wires right. The wire touched metal, and fried my Turn signal relay. I think that is what fried the wire they were telling me about too. So i did a seal job on it. Ever since i have had this problem. I will try that though and see what happens. I hope it is something like that. I want to ride it, not stare at it.. I REALLY appreciate all your help. I will have to try that now...