Tested out the top speed of the fzr today and was only getting just under 160kmh, took a while to get there aswell. that was in 5 gear and 6th just had nothing. Is this normal for a 91 fzr? i though they were capable of 180-190kmh? <!-- s --><img src="{SMILIES_PATH}/icon_sad.gif" alt="" title="Sad" /><!-- s -->
That 180k is around normal top speed of the FZR. I only ever had mine once to 150k in 5th and got there quick and still pulling strong but run out of track. Sounds like you may be down a bit in power. <!-- s --><img src="{SMILIES_PATH}/icon_sad.gif" alt="" title="Sad" /><!-- s -->
Depends on your bike really......is it in tune? are u running too lean? mines actually running too lean at those speeds, I just cant get enough fuel into her (lol who wouldve thought on a fizzer <!-- s:-? --><img src="{SMILIES_PATH}/icon_Eyecrazy.gif" alt=":-?" title="Eye Crazy" /><!-- s:-? --> !), but its a trade off for me, my throttle is more responsive down low now, and fuel economy is around 200Km's per tank. Talkin to my mates who race, I need bigger jets (we did a lil mod that nearly all cbr250 and fizzer track bikes do......it works <!-- s:Biker1: --><img src="{SMILIES_PATH}/th_Biker_1.gif" alt=":Biker1:" title="biker_1" /><!-- s:Biker1: --> ) to get my top speed of 180 back and to get it to pull harder over 140-180km/h But to be honest with ya these bikes are fairly tame, good for 250's, but a r6 will wheel spin on a wet road at 150km/h under full throttle......lol. And the other thing is, if ur bike is going between 0-150km/h as pretty much the fastest 250 around (except for tzr250 or rgv 250 smokers) thats all ya need......well thats what i tell myself everytime i top out at 160 anyways lol <!-- s:biker4: --><img src="{SMILIES_PATH}/th_Biker_4.gif" alt=":biker4:" title="Biker 4" /><!-- s:biker4: -->
yeah it feels like it lacks abit of power, i had heaps and heaps of straight road and it took awhile to get to 160 and just wouldnt pull any further. what do you recommend i do? tune it? bigger jets? bigger fuel pump? i think its all stock apart from and exhaust. its done about 50,000kms aswell. i would like to do some work on it myself but all the technical manuals are in japanese which doesnt help. could i possibly have a small spoket on or something? whats the number of teeth for a stock sproket? what does it cost around to get a good tune, and where would be a good place to get it done in melbourne? prefrebly in the city. if theres someone in melbourne that wants to jump on it and see how its running compared to their fizzer pm me.
Well the mod thats common amongst my mates, is modifying the air-intake box cover. We drill a number of 30-40mm holes in the top cover to allow more air thru into the carbs. Now before everyone starts lecturing me on the wiseness of this mod,(I have seen other posts with less than forgiving responses to this) there are a number of things you need to know about my setup. I have bigger than stock jets, the engine is on its second rebuild (this motor has been used for track work for a number of years) so its slightly above spec in terms of bore and compression, and no I dont use pod filters or K&N filters or any aftermarket filters, just the OEM Yamaha. The motor is all complianced and vin'd so its all legal etc. I just got it out of my mates old track bike, had it rebuilt(by him) and at the time I had a stock airbox cover however it was running too rich, not becoz of the normal fizzer issues but becoz the jets are bigger and it wasnt getting enough air. So i drilled the top cover, he said I should do 2 at a time take it for a ride see how it performs etc, me I thought I would be clever and do six, now I have too much air, so its running to lean at top speed. I have a spare top cover just havent been bothered modding it properly to fix the lean issue. Will do that this weekend. One other thing though, is it does sound great, sounds like a true track/sportsbike.......but make sure if you do this you have bigger jets or its fairly pointless. To those who say u can never get them to run right, I disagree. I know a number of guys who have raced bikes for years, Paul @ Hinterland Motorcycles(Nerang) used to do this on his Honda CBR400 for example, he's in his early 60's now and swears by it.......IF u mod ur carbs to suit. Ok now i am waiting for the h8er's lol <!-- s:biker4: --><img src="{SMILIES_PATH}/th_Biker_4.gif" alt=":biker4:" title="Biker 4" /><!-- s:biker4: --> PS - heres a link http://www.geocities.com/motorcity/speedway/2476/airbox.htm Google around and theres more, and yes I know its heaps safer with EFI bikes with o2 sensors coz they dynamically adjust everything, but its completely viable on venturii carbed bikes too. <!-- s:2cents: --><img src="{SMILIES_PATH}/th_2cents.gif" alt=":2cents:" title="2cents" /><!-- s:2cents: -->
would you get defected for drilling holes in the airbox? ps. can some 1 answer my questions!? edit: its a 3LN btw
I dont believe so. Try this link for sprockets http://www.fzr250.com/viewtopic.php?f=21&t=2981&hilit=sprockets Get a tune up and service is my advice. Use the yellow pages, and ask the mech if he knows Fizzers. There are no manuals in english for this bike, sorry. But heaps of info on this site, just use search function. You can however get a parts guide and use the FZR400 manual(which is in englisch) for most things. There's a link around here somewhere, no doubt poor old daves got it lol <!-- s:mrgreen: --><img src="{SMILIES_PATH}/icon_mrgreen.gif" alt=":mrgreen:" title="Mr. Green" /><!-- s:mrgreen: -->
Charlie - if your bike has 50000km on it, there's a very good chance you're in DIRE need of service. Valve clearances tighten up with time, so the valves don't seal properly - power loss. Worn clutch plates, tired clutch springs, notchy basket and hub - the slipping might not be obvious (half throttle at 4k and ZING! to redline - you coulda heard me on the other side of the paddock that day... <!-- s --><img src="{SMILIES_PATH}/icon_mad.gif" alt="" title="Mad" /><!-- s --> ) but there is still power loss. God only knows what your carbs look like - clogged, worn ,utterly out of sync. Same thing with your air filter - full of crap = empty of power. Ignition - same thing; check the plugs, wires, coils. Has your EXUP *ever* been maintained? Cleaned, lubed, adjusted? If it isn't opening all the way, kiss your top end goodbye. You might want to do compression and leak-down-tests. You mentioned the sprockets - how many frozen links in your chain? Is it skipping? You wondered about a too-small front sprocket, but the smaller the front the HARDER you accelerate. Obviously you run out of revs sooner, but that doesn't sound like what you're describing. A too-LARGE front (or too-small rear) will cause the motor to run slower with less power at a given road speed; if you're trying for max-v, drag may be overwhelming your output before a stock arrangement would. What do your wheel bearings look like? Do they spin freely, or do they sound like footsteps on a gravel driveway (crunch crunch crunch)? Long story short - get dirty, get busy, get into it. Enjoy! (Don't be afraid to ask for help)
ive only had the bike for about 1500km's. the previous owner was mates with the mechanic at the bike shop and he did all the work on it, so its been maintained well in the servicing department. yeah im going to get it all checked over by dynobike soon when i find the funds. i was riding at 120kmh today on the highway and the oil light kept coming on every 15 minutes or so, i would drop back to 80 kmh and the light would switch off. the oil level is only a tincy bit under full. was freaking me out, i didnt want to seize the engine. i meant the rear sprocket being smaller than stock, but obviosly its standard as it sits on 10000rpm at 120kmh. the air filter and box looks clean aswell as the carbs cas i had the air box off to change the accel cable the other week when it snapped. wheel bearing have no noise and seem to spin well. its got an aftermarket pipe which im no to sure on the brand cas the previous owner put a yoshimura rs3 badge on it. how do you check the exup? So the bike hasnt been serviced since i bought it. what would be some things that i could do myself before i take it into dynobike. nothing too hard (jetting, cleaning carbs) as i cant read the jap technical manual and im new to working on bikes, ive done abit of work with cars
well it doesnt matter now, my bike got stolen last night from a lock up garage in carlton. no insurace
