FZRSupport: the FZROnline Archive

Hello so I has a 1991 FZR 600 and it seems to hit the rev limiter ONLY if I try to accelerate very quickly and go to WFO. In first gear it will do It around 7k, and the rest depending on when I go to WFO it hits the rev limiter at 4.5k-6.5k. If I accelerate slowly the rpm's won't hit a rev limiter. The alternator has been changed and checked and is within service manual spec. The coils are also within spec. And I just serviced the carbs. I'm thinking either the ignition advance is going bad or the CDI is going bad but would like some input on the matter. Thanks and always keep the shining sideup!!

You are not hitting a rev limiter but are probably running rich in the mid range. Basically you need a tune up.

pefrey wrote:You are not hitting a rev limiter but are probably running rich in the mid range. Basically you need a tune up.

I'll give it a shot, but I feel pretty confident it's not the air/fuel mixture. I just completely did a service with a stage 3 jet kit, pod filters, had the carbs synced an pulling the correct amount of vacuum an everythig. And it's not like it just Boggs down like a normal rich mixture, it actually makes a sound like it's redlining an hitting a rev limiter. That babababababa sound.

Your carbs are jetted so rich the engine is staggering - if you bring the revs up slowly, it's all good, if you whack the throttle open, it falls flat on its face.

Pull your carbs, strip and clean, find out what the heck is going on.

DonTZ125 wrote:Your carbs are jetted so rich the engine is staggering - if you bring the revs up slowly, it's all good, if you whack the throttle open, it falls flat on its face.

Pull your carbs, strip and clean, find out what the heck is going on.

I know they're clean becsause I was having this same issue before and after I took the carbs off and installed everything. And I cleaned all the fuel lines fuel pump, and gas tank with fresh clean gas. But I'll try going a half turn in on te fuel mixture screw. It's currently 3 turns out from slightly seated per order of my dynojet kit instructions.

Oh I forgot to mention also, it also only does this on gear. If I'm in neutral or have the clutch pulled in its also fine. It only happens when there's a load on the bike. Shit I think I may of answered my own question. Float height.

What main jets are you using? What air filters and exhaust are you running? The mix screw won't do a thing; this problem is your mains.

Could float height be the issue? Stupid me that's te only thing I never check when I service my carbs in my bikes.

DonTZ125 wrote:What main jets are you using? What air filters and exhaust are you running? The mix screw won't do a thing; this problem is your mains.

I'm using Dynojet 130 main jets with K&N pod filters and a Vance and Hines SSR-2 slip on.

The stock main on a 600 is a Mikuni #107.5. The DJ and Mikuni don't line up exactly, and you should be going up a bit, but the 130 is obviously WAY too big. I'd suggest dropping 3-4 sizes, then go for tune and test rides.

DonTZ125 wrote:The stock main on a 600 is a Mikuni #107.5. The DJ and Mikuni don't line up exactly, and you should be going up a bit, but the 130 is obviously WAY too big. I'd suggest dropping 3-4 sizes, then go for tune and test rides.

The kit came with a 126 main jet and 130 main jet so I'll put the 126 in instead and let you know how it goes.

So I went down to the 126 and still doing the same thing. I don't think it has anything with carbs because like I said before it was doing the same thing when the bike was all stock with stock jets and air box.

Assuming you have the proper main jet, a mid range issue is the result of incorrect needle setting. The following procedure is spot on for setting your carbs up correctly. Keep in mind that having pod filters makes it more difficult to properly set up carbs.

http://www.factorypro.com/tech/tech_tun ... gines.html

Also, if you think it is ignition related, there's a procedure in the Wiki showing you how to diagnose that.

http://fzronline.com/wiki/doku.php?id=v ... flow_chart