stuttering fzs 600

[red98]

cheers guys...a couple of good links there  ....should have time on saturday to put the bike back together...its been off the road for a few weeks now,iam starting to miss the old girl  :\

[red98]

evening all....bike back together today and just came back from a test ride.....its better but i have a flat spot between 5 / 6000 rpm (flat spot not stutter) and a stutter at 8000 very very brief (more like a jolt ) but it does pull through,tryed a few times and the same happens every time at the same revs...its a lot smoother now upto 5000 and it dose pull to the red line.....your thoughts  please ladies and gentlemen  :\

[red98]

morning all....iam running out of ideas now...going to check the tps (throttle position sensor ) this morning,just out of interest dont think thats the problem,just something else to cross off the list...still looking on ebay for cheap parts that i can swap to identify any faulty parts,iam pretty sure the carbs are ok so looking at coils and ecu.....question,ive swaped a few ecu`s on cars and they needed to be set up using a laptop (vag com) i pretty sure the fazer is just plug in and go...anyone had anything to do with these ?

[red98]

hi...just been out to the garage to check the tps according to the haynes manual.......turn the ignition on and disconnect and re-connect the sensor wiring this puts the unit in `adjustment mode` the tacho should read 5000 rpm,if it reads 0 or 10`000 rpm the angle of the sensor is either to narrow or to wide...........mine was reading 10`000 so needed adjusting.......so iam now thinking,do you need to readjust the tps if you have disconnected the unit,as i did several times when i removed the carbs  .....test ride tommrow as dinner with the out-laws today  :\

[Fazerider]

How bad is the flat spot at 5/6000 rpm? That's where one is engineered in to get the bike through the noise tests. Are you on stock downpipes and can?
I hope the TPS adjustment did the trick. If not, might be worth either swapping it or at least checking the output. A meter across the lower two terminals should show a smooth variation from roughly 1kΩ to 4.4kΩ as you open and close the throttle, if the track is dirty you'll get higher or even open circuit readings at some points. No, just unplugging and replugging the TPS doesn't mean you need to go though the adjustment routine.

Yes, the ECU is pretty dumb... it doesn't need to be set up, just plugged in. Those on some vehicles have loads of sensors and injector characteristics to "learn", our carburetted engines don't have to worry about keeping those fragile catalysts alive so the only thing it'll need is another TPS position check.
Does the 8000 rpm hesitation happen regardless of throttle position? If you hold the throttle open at 4000 and just let the bike accelerate it will eliminate some possible causes of the problem 'cos the butterflies and TPS position won't be changing. An ECU or coil fault that only occurs at one particular engine speed sounds a bit unlikely... and the only other things that would be moving are the carb slides.

[red98]

thanks fazerrider for confirming the ecu set up,i was pretty sure but nice to have a second opinion,standard downpipes and can,no non standard parts on the bike its as it left the factory,iam going for another test ride this afternoon as not up the outlaws now    which also gives me time to check the output of the tps,iam happy that ive found something wrong that explains the fault,upto now everthing ive checked has been ok , after 40,000 miles i was expecting to find something...well done yamaha....loads of advice/tips in your last post,which i thank you for,most helpful.....will up date tonight ,i think iam getting close to solving this one  

[red98]

evening all.....been on a test ride,flat spot is still there along with the stutter at 8000  :\ ,but not as bad as it was .ive also done the checks on the throttle sensor.
FAZERIDER i think you may have your wires crossed ,when i put my meter across the lower 2 terminals i get a reading in reverse,using the blue and black wires ( top and bottom ) its the right way round,dos`nt realy matter as the same reading is given,i also checked the resistance range uaing the yellow and black wires ( middle and top ) results below

max resistance...............blue and black wires..5.41.................haynes manual..5.0 +/- 1.5k-ohms
resistance range.............yellow and black wires..0.81-4.15.......haynes manual..0.0 - 5.0 +/- 1.5k-ohms

so no problems there then......it is running better today and around town below 5000 taking it easy on the throttle you would`nt know the problem was there,but as soon as you hit an a-road to have some fun its back...aghhhhhhhhh

thanksa again for your help FAZERIDER   

[red98]

ummmmmmmmmm......what to do...what to do...what to do    :\  :\

[ade the blade]

torch it and buy a puch maxi..........feel the power !!! :lol

[red98]

lots of thinking this week...iam going to strip the bike one more time and check everything again,might even get some new plugs,they were replaced at the end of last year and the bike has not been used but just been sat all winter and new plugs will be another thing i can cross off the list,iam also going to use the yamaha seals off the old inlet rubbers as no doubt they will be better quality than the new pattern ones.....thats my weekend sorted  :\  :\

[ade the blade]

good on yer mate...........i couldnt afford the time on hers anymore and i wasnt going to throw money at it forever and a day :rolleyes  good luck with yours though !!

[red98]

cheers ade,ive not spent much money on it so far just service items and the inlet rubbers,spent quite a bit of time on it though when i should be getting on with the new bathroom,causing a bit of friction at home,i seam to be the only one that knows which one is most inportant    :lol

[ade the blade]

tin bath in front of a fire just as good..........job done.......then back to really important stuff . keep us up to date mate :thumbup

[red98]

evening all....stripped the bike down again today,carbs off and removed the inlet rubbers,there pattern parts and as good as the origanals i dont think i have a problem with these,to make sure i used a smear of instant gasket on the mating surfaces making sure they were clean and re-fitted them,when i first fitted the rubbers i eased the carbs and air filter box back and eased the rubbers out without removing the carbs,its much better to remove the carbs to fit the rubbers,its easier to clean the surfaces and to get to the securing bolts making a much better job,i also removed the petrol tap on the tank to check the gauze filter,no problems there,while i had the tank upsidedown i noticed one of the breather tubes was blocked,looked like graphite grease,i used some degreaser and some mig welding wire to clear the tube and blasted them with my comperssor and a squird of wd40 rinsing with petrol to finish off,all clear now,looked like it had been blocked for some time ,also fitted some new ngk plugs (cr9e) had one slightly loose connection on one of the coils so cleaned and tightened that up and put the bike back together.....the stutter is still there.....flat spot between 5/6000 rpm and a stutter at 8000  :\ :\ :\ 
in the haynes manual it says that a good yamaha dealer can check ignition items off the bike such as coils,cdi and ignition control unit (which i think is the ecu ) has anyone used this service ?
iam going to see a good friend tommrow lunchtime whos just set up his own bike workshop who worked for my local yamaha dealer to see what he thinks,might leave the bike with him to see if he can identify the problem by road testing,your thoughts please folks .....

[ade the blade]

good to see ya still at it mate   i found a video on me camcorder i made a couple of weeks back to post on here but never got round to it. take a peek and see what you think. her bike is no more so this doesn`t really apply anymore but maybe it could ring a bell with others ! good luck with your spanner man
motorcycle fuel pump problem=

[red98]

hi ade....good video,shame i have no sound on my computer  :\  ill see if i can watch it at work tommrow,yours is a slightly later model than mine but more or less the same, i`ll let you know what happens tommrow 

[red98]

another thing i spotted today,i have a small hole in the exhaust down tubes where two go into one,ive welded this up a couple of times before so looks like ill be needing a replacement,anyone have a good secondhand replacement for sale 

[Dead Eye]

I actually do have a set of spare downpipes - they are stainless steel (certainly dont look it anymore) but have no holes and only marginal surface rust and by this I mean it should scour brush off. Ive been meaning to get them cleaned up and put them up for sale. I also have the stock can as well, again with no faults.

I renewed the system to a) make the bike look pretty (naawwww) and b) the money was burning a hole in my pocket...


Edit: Btw ade, did you replace the fuel pump in the end? (It's late and im too lazy to read through the 3 pages in the other thread )

[red98]

morning dead eye......very interested in your down pipes,have sent you a pm 

[ade the blade]

I actually do have a set of spare downpipes - they are stainless steel (certainly dont look it anymore) but have no holes and only marginal surface rust and by this I mean it should scour brush off. Ive been meaning to get them cleaned up and put them up for sale. I also have the stock can as well, again with no faults.

I renewed the system to a) make the bike look pretty (naawwww) and b) the money was burning a hole in my pocket...


Edit: Btw ade, did you replace the fuel pump in the end? (It's late and im too lazy to read through the 3 pages in the other thread )

no mate.......not prepared to throw money at the thing willy nilly. got shot !