Hi , I tried doing a top speed run on my 1990 fzr250r (unrestricted model), 1 to 4 gear I can get up to 18k rpm fine no problem, the when I shift into 5th (not using the clutch) it stay in around 16k 17k feels like I've hit a limiter (have power then no power the back to power) with throttle fully open. So far my bike will on do 165-170 km/h In 6th gear but feeling like I'm on a limiter Any suggestions? Thanks Adam Sent from my SM-G975F using Tapatalk
Sounds like not enough fuel getting into carburettors. Check all fuel tap, filters (tank and inline) and the small gauze filters behind the needle seats (if fitted) and check fuel bowl heights too.
Could be fuel supply issue as Murdo suggested. There are other things that could be going on too, in particular the speedo restriction. By Japanese law these bikes are fitted with a restriction that once you reach around 180km/h on the speedo, there is a circuit activated that changes/retards the ignition advance to prevent going faster. On the back side of the speedo under the needle, there is a hall effect sensor. The speedo drive goes off front wheel speed, so tyre size can affect the reading. There's also the fact that these bikes may just not have the outright power to hit redline in 5th and 6th.
I will recheck the carbs and fuel pipes/filter , but it doesn't feel or sound like a fuel issue because it is perfect in every other gear.(I cleaned them out recently) The factory restriction makes sense except for the fact that I can't even get to 180km/h where the restriction is normally, that's why it is so odd to me that it feel like a limiter at 165,170km/h , I'll have a look behind the speedo Sent from my SM-G975F using Tapatalk
Tyre are also OEM speedo should be accurate, My friend has a fzr250 as well and it can rev up to 18k in every gear and go past 180km/h with no hassle Sent from my SM-G975F using Tapatalk
Assuming no limiter then: As Linkin said, it doesn't have enough power. This can be because 1/ low compression 2/ wrong amount of fuel both rich or lean. On the lean side it would be from a supply issue, and on the rich side because of morons who make it richer by thinking that it will make their bike faster.
Couldn't agree more - first step would be to check the fuel supply and the fuel height in the float bowls, if they're not getting fed right, they won't run right
Check for a speed limiter first. It is usually just a little vane inside the speedo that spins around with the needle and activates a sensor when it gets close. Some misalignment of the vane could cause it to cut in early.
I have gotten the instrument display off , anyone have a photo of what this sensor looks like ? After I take the back of of this Sent from my SM-G975F using Tapatalk
I took the four screws out at the back where the speedo cable goes in but the trip meter reset Dail is stopping the speedo unit from coming out , does the trip reset dial pull out ? Or ... Sent from my SM-G975F using Tapatalk
Not sure on your bike. On the mc22 Honda, you have to pull the trip knob off. There might be a screw holding it onto the shaft.
Just answered in the other thread... but it looks to either pull out or possibly unscrew... definitely no screw to hold it in.
Hi guys I went to a different topic to check the factory speed restriction mine it cuts in at 170km/h by the look of it So that's what is stopping it from redline ing in 5th cant go any faster! , haha the question is now do I remove it Sent from my SM-G975F using Tapatalk
