flat spot. . .

NorCalRyda · Post by **NorCalRyda** » Mon May 23, 2005 8:18 pm

wuddup fellas, took my bike out today since it was such a nice day. this was my 1st time really getting on it since i bought it a few months back. while riding i noticed that everything felt great with the exception of a flat spot in 1st gear. off the line from 1k - 3k it feels like its really lean. i get a waa-waa-waa stuttering feeling. if i blip or ride the clutch, on take off, it goes smoother but id rather not jack my clutch up. my exup was taken off by the previous owner & im in the middle replacing the exup parts that are missing. he also had a D&D race pipe that i swapped out for a V&H race pipe. i really like how it sounds now, the D&D was just way TOO loud. i also noticed that it rides better with the V&H. thanks in advance - tone

Post by **FZRDude** » Mon May 23, 2005 8:24 pm

Get your EXUP all sorted and let us know what the results are. If your jetting/float height/needle height are all correct. Of course I have no clue what I'm saying about the carbs, but I do pay attention. <img src="http://img.photobucket.com/albums/v209/ ...  There are some who call me........Tim? Top Speed = Mach 0.197 or so...  1994 FZR 1000 <img src="http://img.photobucket.com/albums/v209/ ...

ExupElvis · Post by **ExupElvis** » Tue May 24, 2005 12:05 am

<blockquote>Quote:<hr>with the exception of a flat spot in 1st gear.<hr></blockquote> Is it just less noticeable in higher gears, or does it seem to go away completely? A low speed flat spot without the EXUP valve is generally considered normal. Also, what year bike NCR? Later iggy boxes had more mapping built in - might be a contributing factor.  genisx1atyahoeydotcommamomma

NorCalRyda · Post by **NorCalRyda** » Tue May 24, 2005 5:45 am

after i shift to 2nd, i get a stutter like in 1st but its ALOT lighter & goes away pretty fast. after that its a beast all the way up the gears. smooth too. if its fact waht you said, imma have to get the exup working. any clue of how much all those little doo dads and cables are? ohh i got a 97'. is more mapping a good thing or bad thing? Edited by: <A HREF=http://p072.ezboard.com/bexupbrotherhoo ... CalRyda</A> at: 5/24/05 3:55 am

dragracer1951 · Post by **dragracer1951** » Tue May 24, 2005 6:54 am

Just a quick thought... How many miles and is it better hot or cold? You guys know what I'm thinking....Emulsion tubes, or is it just rich at the very bottom... Jim <img src="http://img.photobucket.com/albums/v209/ ... Cheers.gif" style="border:0;"/> <img src="http://img.photobucket.com/albums/v209/ ... states.gif" style="border:0;"/> Hey Kid...Is my taillight working?

ExupElvis · Post by **ExupElvis** » Tue May 24, 2005 8:34 am

Ok, a '97 means it's a YZF - and please do consider Jims questions above - it'll help to find to the cause. More mapping is generally a good thing, but it can make troubleshooting a bit trickier also. Does your bike should have a gear position indicator on the dash? I've heard that the later (and I think this includes the '95 FZR) ignition boxes had a gear position input to the iggy box, and that could cause acceleration to feel different between gears. I wouldn't be any help if I just started guessing for you Tone, But check with the folks at Factory Pro and see if they can help with more info - I think you might be able to trick the iggy box into thinking it's in any gear you want. [Edit] Hey I just checked a blowed up YZF I have hanging out in the garage, It does have a shift indicator lead for every gear. Check the the wiring down there Tone, maybe it's nothing more than a broken wire.  genisx1atyahoeydotcommamommaEdited by: <A HREF=http://p072.ezboard.com/bexupbrotherhoo ... upElvis</A> at: 5/24/05 8:22 am

NorCalRyda · Post by **NorCalRyda** » Thu May 26, 2005 1:32 pm

jim - shes got a little under 20k on her. im gonna have to get back to you about wether she runs better hot or cold. not enough riding on her yet to tell. elvis - my bike dosnt have the gear position indicator on the dash.

dragracer1951 · Post by **dragracer1951** » Thu May 26, 2005 2:22 pm

have a look at the emulsion tubes...put the needle in there and you can see pretty plainly if it is egg shaped. If it is replace is your only move Jim <img src="http://img.photobucket.com/albums/v209/ ... Cheers.gif" style="border:0;"/> <img src="http://img.photobucket.com/albums/v209/ ... states.gif" style="border:0;"/> Hey Kid...Is my taillight working?

ExupElvis · Post by **ExupElvis** » Thu May 26, 2005 4:48 pm

<blockquote>Quote:<hr>my bike doesn't have the gear position indicator on the dash.<hr></blockquote> Ok Tone, Here's what I'm thinking - The ignition for some reason isn't giving advance in first gear, I don't see that as a carburation problem myself. (If, for no other reason - than that it pulls well in the upper gears) The YZF engine I have has four wires coming off of the shift drum cap (under the clutch cover) as opposed to the FZR's, which have one. Position indicator or not, there is a reason for those extra wires. That is why I'm convinced the later iggy boxes have gear specific ignition maps (besides having heard that from a guy who built Yamaha race bikes in the '90s) - So I would recommend at least pulling the sprocket cover to see if the wiring down there is all secure and tight. While typing this out and listening to FZRdude Tim on the phone with one ear - I'm also reminded that there is a throttle position sensor on the YZF's, so check that out also, if you can find some specs.  genisx1atyahoeydotcommamommaEdited by: <A HREF=http://p072.ezboard.com/bexupbrotherhoo ... upElvis</A> at: 5/26/05 3:09 pm

dragracer1951 · Post by **dragracer1951** » Thu May 26, 2005 6:01 pm

Damn....New fangled things!!! I got totally caught up in the carb thing...could very well be a cdi gear position thing Jim <img src="http://img.photobucket.com/albums/v209/ ... Cheers.gif" style="border:0;"/> <img src="http://img.photobucket.com/albums/v209/ ... states.gif" style="border:0;"/> Hey Kid...Is my taillight working?

rsvmiller · Post by **rsvmiller** » Mon Jun 20, 2005 10:19 pm

Hi all, I just bought a 97 YZF California version. Stock air filter and Yoshi slip on. The bike used to stutter badly from idle to 3Krpms. I checked the exup valve, and the cable were very loose. I set them up and the stutter now goes from idle to 2Krpms. I also reset the idle mixture screws to 2.5 turns from 1.3/4 I found them at. Better I think. At any rate, the bike back fires on a closed throttle from high res. Besides that, the bike is great. Fast and handles very well with brand new Pilot powers on. My other bike is an Aprilia rsvmiller. these bikes are so different, but both are a riot. Thanks for any input on the flat spot. The YZF was dropped on it's right side, Thanks for any feedback from the old timers.

rsvmiller · Post by **rsvmiller** » Tue Jun 21, 2005 10:33 am

old timers as in long time owners, not walker bound... not about that flat spot...

rsvmiller · Post by **rsvmiller** » Wed Jun 22, 2005 5:41 pm

well glad we got the walker part cleared out, I shall adress you only as wise sages who need to impart YZF Thunderace knowledge to the unwashed masses...How is that? I went riding in the Santa Cruz hills yesterday for my first proper romp on the YZF and I like it a lot. Very sweet handling after proper suspension set up, and the flat spot is not an issue since it happens only between idle and 2Krpms. I think the bike is lean though because at 4Krpms in second gear steady throttle it seems to studder just a tiny bit...this is a CA bike and it reminds me of my GS 450 in 81. There am I, dating myself. Has any body added a flat washer under the needle like we use to back then to fatten the mixture a bit?

dragracer1951 · Post by **dragracer1951** » Wed Jun 22, 2005 6:22 pm

If it's stuttering at 4K...it's more than likely rich. Lean just won't answer the throttle and rich will blubber How many miles are on the bike? Have you looked at the emulsion tubes Jim <img src="http://img.photobucket.com/albums/v209/ ... Cheers.gif" style="border:0;"/> <img src="http://img.photobucket.com/albums/v209/ ... states.gif" style="border:0;"/> Hey Kid...Is my taillight working?Edited by: <A HREF=http://p072.ezboard.com/bexupbrotherhoo ... cer1951</A> at: 6/22/05 4:45 pm

rsvmiller · Post by **rsvmiller** » Thu Jun 23, 2005 11:01 am

Hello Dragracer, the bike has 6400 miles. Yesterday I fixed an exhaust leak at the slip on, Yoshimura. The bike had been backfiring under closed throttle. I'll check today if the backfiring is gone. It seems to me as if the bike picks up fine from 4000rpms, it just doesn't seem very smooth at steady throttle at that speed. But the studdering I talk about is definitly between idle and 2000rpms. On the other hand I am also very used to a twin which is very torquy from 3000 rpms on up, and tends toshake a bit,which the yzf doesn't do. I haven't checked the emulsion tubes yet. What are the float heights if one measures with calipers instead of the Yamaha tube gauge?

dragracer1951 · Post by **dragracer1951** » Thu Jun 23, 2005 12:38 pm

14mm Jim <img src="http://img.photobucket.com/albums/v209/ ... Cheers.gif" style="border:0;"/> <img src="http://img.photobucket.com/albums/v209/ ... states.gif" style="border:0;"/> Hey Kid...Is my taillight working?

rsvmiller · Post by **rsvmiller** » Thu Jun 23, 2005 2:02 pm

Thanks Dragracer, I'll take the carbs out tomorrow and check the float height and emulsion tubes for ovalisation. The air leak in the pipe is fixed, but the bike still backfires. I also have a feeling it was used to go to MC Donalds only. The fellow who bought it in 1998 only put on 1000 miles, so maybe that is where the issue lays. On the other hand, when I blip the throttle the iddle seems to hang very slightly before coming back down, ans it seems to get better as it warms up.. Good thing is, if it is the emulsion tubes, I can jet on over to Marin and see the FB folks. I have one of their chips on the Aprilia.

rsvmiller · Post by **rsvmiller** » Fri Jun 24, 2005 9:55 pm

ok Dragracer, here is what I found. All four carbs have a float height between12.30 to 12.42 mm. That is well within the .5mm tolerance. One of the needkle tip is no longer straight. It might have been forced in the emulsion tube. One of the choke plunger wasn't returning all the way, but that is probably not significant. Now I think a dyno jet kit might have been installed because all the main jets are now labeled 130 and don't have the little mikuni emblem which the pilot jets have and 17,5. I suspect the emulsion tube may not be in great shape either. How do I take the emulsion tubes out? From the float bowl side with a punch? ouch. Can you confirm this maybe a dinojet kit insteat of an FP kit? Can I buy just one needle? How do I take the needle out of the slide? Originaly the mixture screws were set at 1.3/4 turns all of them, so the bike wasn't tuned with engine idling I suspect. I now run 2.5 turns, should I go back to the original position once the needle is changed? Questions ,questions, questions. Thanks for any imput.

barneyfzr600 · Post by **barneyfzr600** » Sat Jun 25, 2005 12:40 am

Rsv, if you could post some pics of the needles, I might be able to help ya buddy! Freelance Bodyman I be ridin the Cali Bay Area '88 & '89 FZR1K BOTH ARE ONLY HALF NAKED NOW!!!

dragracer1951 · Post by **dragracer1951** » Sat Jun 25, 2005 5:43 am

First off...12.something is richer than 14mm of float level. The 17.5 pilot jet is more than likely a 37.5 which is stock. You will need to adjust the float level to 14mm Have a close look at the emulsion tubes an dI haven't seen a pic of the needle but I'll bet that if it's buggered up then it is part of the problem also Jim <img src="http://img.photobucket.com/albums/v209/ ... Cheers.gif" style="border:0;"/> <img src="http://img.photobucket.com/albums/v209/ ... states.gif" style="border:0;"/> Hey Kid...Is my taillight working?

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