FZRSupport: the FZROnline Archive

Hey guys, Im having a heck of a time with my 99 FZR 600...heres a little backstory on the bike. my step bro dropped it about 2 years ago and decided
he didnt want to ride it anymore so he put it in a storage unit. The bike sat untouched for 2 years in storage, and one day we were talking about motorcycles
and he told me about his FZR. i was interested, so a couple days later he called me up and said "hey, you want that motorcycle?" i said, "heck yea i do, how much?"
he answered "nothing...its yours". after a few moments of being in shock, i realized that he was GIVING me the bike for free!
sooooo back on track here, After getting the bike back to my house, i checked it over really good. There were a few broken pieces from when he dropped it
that ive already replaced, and i figured since it sat for so long that it needed to have the carbs pulled and cleaned.
So i did just that, I cleaned them VERY well with carb cleaner and compressed air. Carbs back on, Fresh gas, new fuel filter, the bike started up but would not
idle for anything. I could rev it up and it ran great at higher RPMs, but when I let off the throttle the rpms would hang pretty high, around 2k to 2.5k for several
seconds. then the idle would finally drop down to around 1k, then slowed down until it died.

I started doing alot of online research on what could cause this idling problem. it seemed like the main causes were the emulsion tubes wearing out, carbs
being out of sync, carb boots being cracked causing a vacuum leak, clogged jets, that kind of stuff. Kind of sounds to me like its running too lean but
i could be wrong. so first, i pulled the carbs back off, went through them
again with carb cleaner and compressed air, this time i removed every jet on every carb and cleaned each piece separately. i went ahead and ordered
4 new OE emulsion tubes, new jet body gaskets and new float bowl gaskets so went they came in i installed all of the new parts. while the carbs were off,
i removed the carb boots and cleaned and inspected them. there were some cracks but none of the cracks went all the way through the rubber, but i went ahead
and sealed the boots with "right stuff" silicone gasket maker just to be sure. I also checked the choke circuit to make sure none of the chokes were sticking or hanging
up. I bench synced the carbs using a method i found online somewhere, cant remember who it was but it looked like it worked. I adjusted all 4 air/fuel screws
to 2 1/2 turns out, thats what I found to be the correct factory settings.(is that right?)
when putting the carbs back on the bike, i verified that the throttle linkage was routed and adjusted properly, there is enough free play in the cables so
they allow the throttle plates to close completely and still have a little slack after they close.
ok, so after doing ALL of this, the bike runs exactly the same as is did after the first carb cleaning!!! the rpm's still hang, and when they finally drop to idle,
it ends up dying.
There are a few mods on the bike, Has a D&D slip on pipe,(LOUUUD), a K&N Air filter in the stock airbox, and 118 main jets, which brings me to my next question...
im assuming the owner that had this bike before my brother put these 118 main jets in because of the slip on pipe and KN air filter, Are those jets ok to run or do
I need smaller ones? the other jets are all stock sizes, the mains are the only ones that have been changed.
OK....im sorry ive written an entire book about this bike, but it seems people never give enough info when they ask for help so i wanted to give as MUCH info
as possible to get the best answer
sooooo what am i missing here!?!? LOL
thanks so much in advance for any help or advice!!
Jared

Set the IMS screws to 3.5 turns out and try it.

You may also want to grab a infrared temp gun from Harbor Freight and find out the temps for each cylinder. I almost wonder if one of them isn't firing.

Darrin

I will try adjusting the screws as soon as I get home from work today, and
I have a temp gun at home so if I can keep it running I will check the temp on each manifold Pipe. I will post an update after I try these things, thanks!

I built a big carb sync tool so I could sync my carbs, and it works great but I can't even sync them Until I get the bike to at least idle halfway decent. I have to stay on the throttle to keep it running and I can't get an accurate reading.
Also, I dont have the right adapters the thread into the carb boots to hook up the tubes to. Can anyone tell me where I can find the right adapters?

Ok so I turned the screws out to 3 and 1/2 turns and it seems a LITTLE bit better, but still Not right. I grabbed the temp gun and shot each exhaust pipe at the manifold. My temp gun read "OL" on 3 pipes, and 1 of them was reading around 350 degrees...
Not sure what the OL means, but it sure seems like one cylinder isn't firing correctly!

J-ROD wrote:Ok so I turned the screws out to 3 and 1/2 turns and it seems a LITTLE bit better, but still Not right. I grabbed the temp gun and shot each exhaust pipe at the manifold. My temp gun read "OL" on 3 pipes, and 1 of them was reading around 350 degrees...
Not sure what the OL means, but it sure seems like one cylinder isn't firing correctly!

Sounds like you're running too lean at idle. Does it run better with the choke out?

The goal of the temp gun is ::

A. Make sure that all cylinders are firing
B. Make sure that all of the cylinder temps are fairly close at idle. Make sure you measure each of the headers in the same location (same distance away from clinder head). You adjust the IMS (Idle Mixture Screws) in/out to make them match up.

When I pull the choke out, the engine screams up around 4 to 5k. it runs a lot smoother at Higher rpms, but when I take the choke off the idle drops down around 1k, then slows even more until it dies. It I give it throttle it stumbles and almost dies, if I kind of feather the throttle it eventually revs up...but when I let OFF the throttle,
That's when the rpms hang for a while, then after a short time it drops to around 1k,
Then slows until it dies eventually.
I pulled a couple of spark plugs and they don't look too bad. Tomorrow I'll bring home a spark tester and a borascope from work to inspect the pistons and cylinder walls.
I'll post a report when I check those things, but I still feel like I'm missing something... there's gotta be SOMETHING causing this funky idling problem,
I just can't figure out what it is:-(
Mo

What do your airbox to carb boots look like?

The boots between the airbox and carbs were very hard... so hard that I could not get them to fit On to the carbs. I tried pulling them out and soaking them in transmission fluid, but it did no good. I ended up pulling them back out of the
Air box, flipping them around and putting them back in. The other side of the boots
Fit perfectly on the carbs, but they were a bit loose in the airbox so I used the silicone gasket maker I have and sealed around them which made a nice seal. Since I've removed the air box several since I did that though, one of the boots came loose so I have to re seal it.
Maybe you guys can answer my question...how important IS the air box?
Seems like a lot of people are having problems getting the boots to fit the carbs
Just like me...wouldn't it be easier to run something like stacks with separate
Air filters?

Get a crock pot and some antifreeze and let the boots simmer in the pot over night. I got that trick from don. It works.

Stacks and pods are great for the track, but even with a good stand-off spacer you give up a lot of mid-range.

Replace or recondition your carb rubber.

IMO you would be going backwards by shelfing the airbox and running pods at this point. Save that design of experiemnt for after you get the idle issue sorted. A bunch of good ideas have been suggested to this point for you to follow up on and you are so Hooray! But in following this thread I still think you have a compromised idle circuit in one or more carbs or an air leak(s) somewhere. But again this is just one man's opinion.

Hang in there bro, we'll get you through this, there are some excellent wrenches on this site, present party excluded.

I agree! It sure does seem like I have an air leak.
So if the boots between my carbs and air box are leaking, that would cause it to run lean?
I always thought that it would have to leak air between the carbs and the engine for it to run lean.
I really appreciate all of the comments and help so far! I'm positive I'm in the right place:-)
I am seriously looking into selling this one and getting another R6 though...I miss my R6 so much and even if I get this bike going, it still won't compare to an R6..

An engine can and will run lean if it is leaking air from any where that involves intake of air. My fzr was running lean real bad. I took the carbs off and checked them, made sure they fit snug into the intake boots on the engine, and made sure the air box boots were tight. When I was done I sprayed starting fluid around it to make sure it wasn't leaking.

Well maybe my airbox is the whole problem then?
When I get home from the gym today I'll work on getting the boots to soften up so they fit back on the carbs. I wonder how much they cost to replace?
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