Hallo, firstly seeing as though this is my first post, i would like to introduce myself.. My name is Brendan, i'm new to the entire motorbike and maintenance scene.. i have an FZR 250, the 3LN model i believe an 87? when i bought the motorbike, the guy i bought it off said it had a few rattles and it was running a bit rough and explained to me that it just needed a new controller.. me not knowing anything about the motorbike in question.. believed him.. thats when my problems started.. i found this forum quite quickly and seen a couple of problems i had were already on here so i set about fixing them.. i have a reasonable knowledge of light maintenance.. being a farmer working around tractors and such i know how to minimal work, fuel filters, oil change and filter replacement.. etc.. so i went with what i new first.. The bike had trouble kicking over, so i got out the multimeter and went to work on the battery.. it had a dead cell and was flat out turning the starter motor.. so i went out and replaced the battery.. got it to kick over.. got it started and it was idling.. up and down.. wouldn't quite sit there.. constant.. i thought i better give it a good servicing, as the guy said that he had dropped it just recently.. i read through the fzr 400 service manual and through the specs that were gathered on this site.. I Drained the oil. and from what i gathered there should have been roughly 2.2 litres all up, 2 in the crankcase and .2 to fill the filter? i drained out roughly 3.5 litres and the oil was almost pure petrol. i pulled the filter and what came out of that was almost tar. replace both oil and filter? i thought that having the motorbike trying to fire with oil as viscous as petrol could have done a considerable amount of damage, but i hoped and i prayed this was not the case.. i replaced with the correct amount of oil according to the 400 specs half way between the two etches in the viewing window standing upright. i thought about the problem with the bike stalling as well.. the first time i test rode the bike before it was dropped. it had a few problems. a) had a loud clicking rattle at idle, clutch in/out doesn't change with revs.. disappears under load. b) rough to start, wouldn't start properly (dead batt) c) would splutter in the low rev ranges, 4-9k then hit almost what felt like power band a would jump from 11k - limiter almost instantly. the speed and power through the higher rpm was insane. awesome rush though if you held the throttle open a bit and gave it some to take off and continued to power up through the gears, it usually didn't have a problem.. but the minute you start going under 3k it would splutter then die.. d) would randomly just lose all throttle response, as though engine completely flooded. would have to hold throttle completely open to keep motor going. rpm would die and would just chug along.. the minute you took your hand off the throttle it would die.. but start up just fine... then flood.. then die again. had to start, just open throttle enough for it to keep going, after a little bit the revs would start to pick up and you could rev out like normal, come to a give way sign. bike packs it in unless you sat there at 4k rpm.. i replaced the spark plugs.. the old ones were reasonably fouled as if she was running rich. then the main problem. No spark. bike wouldn't start. But i was reading something about the exup valve. and i had a look at mine.. see if that was causing any problems. both wires disconnected at the valve, the butterfly had been takin out, drilled, and the gasket replaced minus the valve. This bike has no exup valve. and it has an aftermarket exhaust that i believe is too big anyway.. and the exup servo was siezed up. freed the servo, performed the initial checks. and the bike had spark again. and kicked over. i havn't taken to a carby cleaning yet, i don't know if i have the time or patience to go about stripping them down and rebalancing them. but the bike is running again for now.. so far, so good. no smoke coming from the exhaust so i am hoping no damage was done due to the over filling of the crankcase. the motor will idle.. and when in neutral will rev out to 18 and back to roughly 900 - 1200 rpm when revving up it will occasionally have a flat spot in the lower rpm range again. i have got a new battery, new plugs, new filters. new oil. have spraid carby cleaner down the intakes... could the flat spot and stalling be due to: a) the carbies being totally gummed up? b) the lack of the exup valve and therefore no backpressure at low rpm? c) The motorbike hates me.. and the knocking sound. i read a post earlier about the cam chain tensioner going bust and it slapping all over the place. arrghh it's been a night mare.. sorry for the horribly long post, but i felt i should be specific. i have some photos of the bike and a video of it starting up, idling and revving out if that helps. oh and my bike doesn't have a fuel pump, it's gravity fed :S Thanks in advance. i've spent hours reading this forum. hopefully i can sort this out <!-- s --><img src="{SMILIES_PATH}/icon_biggrin.gif" alt="" title="Very Happy" /><!-- s --> i love this bike...
Not sure if i can help much. Do you know what the EXUP does??? Theres is a good brief write up about it on Wikipedia i think it was. You need to understand something. A 4 cyl 250cc motor that will scream to 16,500 rpm is going to be two things. Lacking torque and power lower in the rev range. And its also not going to live long and prosper. At those revs even if it is well engineered it is going to be a tad fragile and have a high wear rate. It will be almost 2 stroke like. You may have to clutch it in first just to get it moving. You will have to stir the gears to keep it going, not just wind the throttle, it wont have pickup from low revs. 87 will be a 2KR. There should be a frame number on the frame. It may have been defaced a little when the grey importer put the compliance VIN on it but you might be able to make it out. I took note of mine and looked on the siter here and it tells me its an 8/88 2KR. Over filling with oil should not have hurt it. Perhaps fuel has drained through the engine into the sump. Say if the fuel pump was left on when the motor was off. Or one carb has the needle/seat stuck open. Or the guy you bought it off relised that it was lacking love and tried to shandy up some oil to clean out the black gunge the mtoor is full of. You have it running, thats a good start. Could be a good idea if you were to go into the User control panel and update your details to show a location. Cheers, Bob.
don't give up on your fizzer mate, I've got a 2kr and its a ripper you'll get it back <!-- s:biker3: --><img src="{SMILIES_PATH}/th_Biker_3.gif" alt=":biker3:" title="Biker 3" /><!-- s:biker3: -->
Hello and thank you for your speedy replies! @ rodeobob: Yeah sorry mate will update the profile information shortly. I live in Bundaberg Queensland Aus. just checked the import plates. the chassis markings are as such (3ln-326023) on the mod plate it says it's a 93 3ln3, but the the chassis number read-outs on this site say it's a 3ln5. and yeah, thanks alot for the other information onin regards to the torque etc of the 4cyl engine <!-- s --><img src="{SMILIES_PATH}/icon_smile.gif" alt="" title="Smile" /><!-- s --> i'm learning every day. I have read a lot of information on the Exup valve. what it stands for, how it works, restricting exhaust emissions at low rpm to maintain backpressure giving better torque at lower rpm and opening completely at around 10k as it's not needed. i have some pictures. it's hard to explain though. the previous owner had a slip on fitted to the bike. and has removed the valve in it's entirety. sealing the gap left by the valve with a modified plate. basically. my valve is running at 100% open throughout the entire rev range. i know this would affect torque in the low range.. but will it cause a seeming miss or stutter? i want to pull the carbs as i'm sure they havn't been cleaned in a long long time.. and i know i said that it seems like it's running rich.. but now i'm not too sure.. i replaced the fuel filter as the old one was up the snuff. but being gravity fed (my poor bike has no fuel pump) it seems like there is an air bubble in the top of the fuel filter which isn't going away? the bike still gets fuel.. but maybe it's just not getting enough? i only say this because sometimes the revs just die out.. and i need to hold full throttle to keep her going.. even then.. the revs just chug.. and it won't pick up speed at all.. a few extra notes that may be of use. *the bike doesn't have an air filter. the previous owner removed the foam and just left the metal plate in the box. *if the bike is chugging and choking away, if i just crack the throttle to about 3k rpm position and wait.. after about 10 -15 seconds.. it purrs back to life.. *the revving problem only occurs when the bike is under load. it doesn't have any issues with revving unless in gear.. *the servo was disconnected from the cdi. as there is no reason to have it attached when the valve is not there (i know that the exup valve performs and initial check when the bike is turned to run.. and some people say that effects the cdi if it's not connected as it checks this servo on startup. could that effect the spark or operation of the bike in anyway?) *when i changed the plugs.. i grounded one of the old ones out on the engine fins and looked for a spark whilst cranking it over.. i got nothing..i tried two plugs and still nothing. maybe the bike has droped a cylinder and it's misfiring? i put the lead back on.. unplugged the siezed up servo. and within three more attempts to start. it caught and revved up. i've had a few ideas as to what the problem is.. and i just need a bit of insight as to any other major issues could be affecting the bike. i'm going to pull the carbs and clean out the float bowls tonight.. i don't have the equipment to resynch etc. so i might not strip them completely. i'll see how it all goes anyway i'll try and put the video i made on youtube. so you can hear it. (keep in mind the bike isn't under load when i have it revving out) and the noise i mentioned earlier is in the video. the clicking noise on the LHS under the carbs. i'll try and put a few pictures up of the exup valve and the bike in general. see if anyone can think of something i can't? as for the carbs. a general look in the intakes showed good prospects.. the slides all move freely and all the butterflies and sliders moved in synch when i had it running. the bike has always had a problem with stalling randomly.. like it loses power and just dies? didn't matter what gear.. i'm looking further into the gravity fed fuelling system as a major contender might have to find a fuel pump to add onto the bike. Any Thoughts? I love this bike, i love the way it sounds.. i want to get her running like it should.. i won't give up on this <!-- s --><img src="{SMILIES_PATH}/icon_biggrin.gif" alt="" title="Very Happy" /><!-- s --> Thanks a Million ~Brendan
Cheers, Dont mean to be rude, but; A, its got a fuel pump for a reason. B, by not having an air filter you are messing with the jetting. C, not a good idea to touch the carbs if you do not have the gear to do it once and do it right. Basically if its not all in ship shape dont ride it. Every time you do your tempting fate. If you get it as it should be, im sure it will be fine. Apart from loosing what bottom end the EXUP gave it. Well thats if i hasnt been hurt all ready. If you think about it, what Yamaha learned and put into the FZR gave them the new age 4T dirt bikes. Everyone knows how fragile they are if the maintinece etc is not spot on. Cheers, Bob.
Yeah i understand completely. I bought the bike like this. without the fuel pump exup valve etc. i didn't remove anything. i'm all for the (if it ain't broke. don't remove it from your bike completely) option to vehicle maintenance i also read that that the importers would often remove the fuel pump if it was playing up. as it would generally run ok being gravity fed, although not to it's full potential. i'm at this site as i'm going to overhaul the bike completely. and as i don't have the tools yet, i do have the intention of buying them all. i'm usually a fast learner, and by having a look around on this site. and using most of the information here. i think i should get through this quite alright, my pop is an oldschool mechanic, retired now, but he has most of his equipment still in the shed. and will definitely be helping through the process. i intend to put a new pump in.. just need to know the size of the pump and possibly a wiring diagram as to connect it up right. i think i have seen the leads that were originally for a fuel pump, but i''ll check a wiring diagram to confirm. i've put up some of the pics of the exup valve and the airfilter. (or lack thereof) also the video of the bike running. here are the links. Carburetor intakes with vent pipes cracked and worn http://img35.imageshack.us/img35/2477/img0282lm.jpg Again Close up http://img35.imageshack.us/img35/4172/img0283r.jpg Repaired http://img44.imageshack.us/img44/766/img0285uk.jpg Exup servo http://img502.imageshack.us/img502/5761/img0291q.jpg Exup Valve (where it should be) http://img35.imageshack.us/img35/3246/img0298r.jpg Video of motorbike running http://www.youtube.com/watch?v=hj37Tkqsfz4 If you have any ideas about where i should sart looking than please feel free to share <!-- s --><img src="{SMILIES_PATH}/icon_smile.gif" alt="" title="Smile" /><!-- s --> Thanks again ~Brendan *EDIT: corrected the video link
OK Brendan just read you first post.. Have not got to the rest of yet ERRATIC IDLE SPEED - Check for air leaks and a good fit around the carby boots (between head and carb) PETROL IN OIL - Carbs float valves are not sealing and fuel is overflowing float bowls when parked and running into cylinders, past rings and then into sump. Get that fixed pronto. WON"T IDLE - Idle speed setting is 1600 rpm, and carbs probably need a good service. LOW TORQUE AT low revs - Try get a replacement EXUP valve from wrecker, it will help make the bike more rideable at low RPM. Also carbs probably need a good service. PS - don't run bike without air filter. Soon won't have any rings to speak of.
Thanks for the reply dave. i think that the fuel may have overflowed in the floats when it was dropped. and the previous owner used to leave the thing on reserve all the time. maybe a possibility? i currently have the carburetor out of the bike and have the float bowls off. honestly. the bowls themselves look pretty clean. not polished, but no traces of varnish to be seen, i'll be going over it again with carby cleaner and an air compressor though. all the floats seem to be in tact and the float valves themselves seem perfect. this is the weird bit.. the jets. they are all over the shop. as i was to believe that the two center carbs 2&3? were to be a little smaller than the two outsides. 1&4? please correct me if i'm mistaken. but i read one of your posts on jets and i thought the outside carbs ran 102.5 and the middles ran 100? in my carburetor. the LHS carb runs jets of 100 and 42.5 the next carb also runs 100 & 42.5 the 3rd and 4th carbs are running 97.5 and 42.5.. is this right? and one of the jets is worn to the nines. definitely needs replacing. The idle mixture screw was set to about 2.25 turns. which i figure would make it leaner? and the jet sizes being all over the shop but actually smaller than the factory.. could that lean it all out as well?? i havn't taken the piston assembly apart yet, but if i'm to clean them properly i will have to do it. then i can check and set all of the valve clearances while i'm there. i have all the jets soaking at the minute.. i would have done a float height test earlier but the bike wouldn't run long enough to warm up so i'll put the bike back together.. and give it a run. for now, would it be wise to put the two 100 size jets in the outside carbs and the two 97.5 on the inside? i know this is incorrect but i figure it makes more sense than the former. until i can purchase a rejetting kit? would it be necessary to re-balance / synch the carbs straight away? or can i leave it as is, as i havn't seperated them as of yet, i know by changing the jets around i probably will have to, but i'm getting the vaccuum gauge tomorrow :S. Thanks again! ~Brendan
I would not do anything untill you have a fuel pump. Gravity fed?? In my imaginiation you would need to have the gas tank about 75% or better to get gravity feed, does that sound right??? Ive got no carbs to put on mine to check it out. The fuel has to go down through the filter and back up to the carbs. Liquid wont level out at the same speed it will flow down hill hence the pump. You could try one of the grey import mobs, they should be able to hook you up with a pump. There was a guy on eBay that had one, not sure if it sold. New they are some crazy price from yamaha, the part number is on the forum here somewhere. I would have thought it wise to do the opposite, leaner jets in the outside carbs richer in the middle. The two outer cylinders have extra cooling area that is not shared with the inside cyinders so are not likely to run hot. But that might not be the case. Bob.
I wouldnt be so worried about the fuel pump, My parts bike with running engine didnt have a fuel pump, just gravity feed. Its a 3ln-3. The engine ran freely and the guy down at Yamwreck where I purchased the bike said that many of these sorts of bikes had the pump removed. He said it forced too much petrol pressure into the carbs, wearing them excessively. The only dowside I can see is that the fuel filter (Dirty carbs) was removed and if re installed, gravity might not be enough to get petrol to the carbs. Good luck with your bike!
The FZR 2KR models will only get 2/3 of the fuel from the tank before they starve but the 3LN tank must be higher as they will run ok without a pump. However the correct pump has a 10kPa output pressure (1.5psi). It is a very low pressure, and I believe that you can get generic pumps from Autobarn... Alternately try a bike wrecker as most pumps from other carb bikes would probably do.
When my bike is back together, I will try different combinations of carbs with and without pump, but for now: I assume this bike in the OP is a 2KR because he says it is an 87 model. According to Bruce at Yamwreck, because the 3LN models had a metal fuel tank with no cover, it was mounted higher, meaning gravity could be used instead of the pump. I still dont see why someone would remove one in the first place, unless it had failed. Good luck.
thanks again for the quick replies.. the more i go deeper into this bike.. the more problems i uncover nothings to big i say.. i guess the starter jets are the correct part no. 42.5 but the main jets are not factory. i'll have to buy some new ones from mega motorcycles on monday. wish i could get them tomorrow. how would i check if the valves are sealing under pressure dave? i would assume that because it is gravity fed, the pressure of the fuel coming into the carbies from the tank wouldn't be as much.. so in figuring that.. it would take less effort for the floats to seal when required? all the jets have taken a battering. i assume that the previous owner who has done all of this home botch ups without really looking into the mechanics behind it has been swapping them around looking for the right combination.. where the Flathead screwdriver divot is in the jets, they have been burred and rounded.. very worrying but hopefully like this, the engine fires a little more correctly and i've given all the jets a thorough bath in carby cleaner so if all goes well it should run a little better. when i put the carbies back on, i made very sure to check the carby boot seals and they all look new. probably the newest parts on the bike. maybe the other owner had trouble with them before. i made sure to check that i sealed it as best i could, i'll know for sure when i start it up tomorrow. i'm hoping if i return most of the bike to factory.. it should start to come back somewhere towards it's original glory. i wouldn't mind getting a pump, just to be certain. i have had problems with the bike stalling out of fuel when the petcock was on.. and the fuel was above the on-fuel pipe in the tank.. changed it to reserve and the added pressure must have helped out in getting the fuel to where it was needed.. Thanks again for the help so far, the information on the jets was great dave cheers. and yeah i accidentally said in the first post that it was an 87.. i was wrong. (sorry) checked the mod plate and it says it was imported in 97 and it was made in 93.. Just out of curiosity. does the fuel pump wire through the cdi? i mean it should. but.. where does it normally sit on a 2kr? or a 3ln if someone has a pump on theirs? Cheers ~Brendan
Ok i couldn't believe the last link didn't work. I've got it perfect now. here it is. Motorbike running http://www.youtube.com/watch?v=c4izRlizIdU Cheers ~Brendan
