New Bike Running Rough

[Ahmadi6490]

Just bought an 86' Fzr 600 the other day. Got a new battery and starter and it starts right up. It idles good but once I leave 1st gear the idle jumps to 3k rpm and even when I shift back into netural it'll stay there. Any idea? The guy I bought it from said it might need tuned....as in the carbs and whatnot?

Also white smoke comes from the header area when im in gear. The guy said its beacuse it hasent been ridden in a while. Smells like oil but I cant find a leak....any other reason it does this or should I look harder?

[Archer]

Re: New Bike Running Rough

valves, and white smoke, run it for a while... it should go away, if not needs new header gaskets. I used to be an ASE Cert bike tech.. any other questions give me a shout..

[Ahmadi6490]

Re: New Bike Running Rough

Thanks man I appreciate it. I'll look again for leaks, if not ill just ride it off. One more thing. The previous owern said the petcock leaked a little gas. Before I rode it today I put tape around the petcock and after riding I noticed there was a few drops of gas on the wires and frame but the tape was perfectly dry...any ideas? I did see very fine cracks in the gas lines but I didnt think it would leak.

[StrtRacer98]

Re: New Bike Running Rough

Im a bike tech... Sounds like your carbs need to be syncronized.

meaning that each carb is currently pulling different vacuum, due to the butterfly's being at different angles.

You get a carb sync gauge set, which would be 4 vacuum gauges with hoses that attach to the carbs, and make fine tune adjustments until all carbs are pulling the same vacuum.

For the price of the gauges you can probably get this done at a shop for cheaper.

Also probably wouldnt hurt to have the carbs clean, just because it idles okay doesnt mean the carbs are clean, and while they are in there they should just get done.

Also, your going to want to replace the fuel lines if they are dry rotting (small cracks) because they can start to deteriorate from inside and start gumming up the carb with the crap they lose.

The petcock may need to be replaced too but thats pretty easy and cheap, it just unscrews from the bottom of the fuel tank.

[Ahmadi6490]

Re: New Bike Running Rough

Thanks guys! Tomorrow after class im going to put the air breathers on and replace the fuel lines. I'll let you know if its fixed it. If not I know the carbs will need to be adjusted and the petcock will need replaced or rebuild (i saw kits for them). The guy said it was the small plastic piece that screws into the petcock...he thought i'd need a new one or if the owner before him messed the threads up then i'd need a whole petcock unit.

Btw....any other tips you have? I'm learning a ton...

[black98V6]

Re: New Bike Running Rough

here is a link for a carb synchronizer, I bought one 4 years ago like this but was much cheaper, however I can't seem to find one like this anywhere else now. Mine was around $40 but it has mercury in it and maybe that's why you can't get them anymore. http://www.maxairengineering.com/Mer...tegory_Code=TL

With 4 carbs you will probably want to have one handy, my bike is only dual carbs and they haven't been off from the day I synch'd them 4 years ago.

Also just like your car check for any vaccum leaks. Even if the carbs are synchronized this is going to make it run bad, not to mention they will never be properly synch'd because of the vaccum leak.

Seriously see if you can get your hands on good manual for the bike just like with your car you will be paying out of the nose to get stuff done you can do with just a few tools and some patience. That is one of the cool things about, you don't need as many tools to wrench on them and they are soooo much simpler.

[Ahmadi6490]

Re: New Bike Running Rough

Did some research and the gas leak is from an o-ring inside the petcock. Its pretty useal for the fzr's from what i've read. How could I check for a vaccum leak? I mean where would I spray the wd-40 exactly?

Haven't been home yet to see if the air breathers fixed it or not...I hope thats all thats making it act up when its in gear. I never thought to put the breathers back on all 4 carbs. If not ill check for vaccum leaks then possiably get my carbs fully serviced.

Theres a lever on the side of the bike thats not connected to any wires. When I pull the lever you can see something by all carbs move up...like lifters kind of. Maybe I need to mess with those while the bikes running?

[StrtRacer98]

Re: New Bike Running Rough

The lever on the carbs is probably the choke lever.

and if it's just a bad o-ring, take it out, and go to the hardware store and buy a single o-ring the same size and replace it.

You can rub a little bit of lithium grease on the o-ring and it will help it seat and protect it for awhile and it wont hurt anything.

[black98V6]

Re: New Bike Running Rough

oah forgot to mention the idle problem is proably due to the fact that something is sticking in the carbs. You crank it everything is closed you put it in first give it gas carbs open, come to a stop and idle stays high. Go to neutral idle stays high. Shut the bike down let it sit, start it again and it's fine, cycle begins again. Unfortunately my mortorcycle carb knowledge is limited. I have taken mine apart and rejetted and tuned them for my aftermarket intake but I had really good instructions.
Anyway I'm thinking a servicing of the carbs will have it back to running good. The way bikes sit up, especially older ones, the carbs will gum up over time.

[Ahmadi6490]

Re: New Bike Running Rough

I replaced the gas lines and the leak stopped. The white smoke stopped coming out from underneath the headers. But I see now it's coming out from the oil crank case breather thingy mcbobber. Right where my oil fill is theres a tube coming thats clamped to a k&n oil filter. Thats where the smoke now comes out of.

As for the high idle I think something is sticking. Because with the air breathers on after the engine warms up it'll idle around 3k. I think im going to try and fix the smoke problem and then let somewhere take care of the carbs. Any idea on the smoke problem?

[Ahmadi6490]

Re: New Bike Running Rough

Gas leak fixed. I took the carbs off and they look almost brand new so im guessing the previous owner replaced them. I went ahead and drained the gas out of them. I'm guessing its a vaccum leak and the boots that connect the carbs to the manifold are cracked badly. I pulled them all and i'll get replacements. I hope that fixes the idle issue, if not then it's a tuning issue. Also theres no factory airbox connected to the carbs. Theres 4 aftermarket breathers which may cause the idle because the carbs arent jetted for that much air.

Im changing the oil tomorrow. Hopefully that'll stop the white smoke. Plan sounding good?