Mohawk

As per Fastdruids update which arrived as I was finishing my post. If that is the case then just get a CBR temp sensor & use a thread converter if required. Most temp sensors are just a heat sensitive resistive element, as they get hotter the resistance changes which is what is read by the gauge. A wire conversion may be simpler. Check the CBR manual as it should specifybthevresistive values for the sensor. They are likely to be similar to the VFR’s.

The fan switch on the left rad is standalone. Nothing to do with the coolant temperature monitoring temp gauge. The fan switch turns on & off automatically based on coolant temperature at that switch. The temp sensor is in the V of the engine below the throttle bodies. The output from it should be consistent with the CBR temp monitoring circuit, but if not just replace it with a CBR1000RR one. Have fun. If you built a wiring diagram I’d be interested, as I have plans to upgrade the gauge unit on mine. What model CBR gauges did you go with ?

I’m in the UK. Always happy to help another VFR & BMW owner. What model BMW ?

Sorry didn’t mean to be harsh but bs is bs. There are direct comparisons with dyno numbers that shows no noticeable difference between stock & de-flapped. But that is with NO fuelling mods. When fuelling is modified to suit, then the de-flapped version makes more power higher up, with no losses. Anyhoo 33mpg is poor, regardless.

You could always buy the new TBR full sustem replica that has just been made on here. Will add 5-8hp to your bike depending on what silencers you fit.

OK, so you obviously believe in the helmholtz resonance theory that manufacturers espouse to convince people that they have not restricted your engine to meet noise & emission regs etc. The VFR air box is to small, it’s the wrong shape & wrong material to create a helmholtz reasonance or any meaningful frequency effect. My dyno charts show no losses anywhere with a gutted big air box, with the filter moved to the top & the factory intakes eliminated, that adds about 3L to the intake area volume. Just by moving the filter to the top of the air box it added 5hp to my engine ! So you will have a hard time convincing anyone that the factory setup is best. try keeping your delusions to yourself, unless you have empiracle evidence to back it up.

BS. The air box is VERY restrictive. Check out my threads & mods which prove it empirically, rather than the rants of some armchair warrior. Honda like everyone else has to comply with noise & emissions regs. The 98/99 models had a lower emissions standard applied & gas was cheaper then. But 33mpg (I assume Imperial MPG =4.546L) is bad. I get that from my much more powerful VFR when ridden hard. The guy is not riding that hard. Back to the OP’s issue. Downloaded maps are garbage. Fuel injectors have very different deliveries, so a custom map is the only way to ensure a consistent Air Fuel Ratio & to see how your engine fuelling is performing as stock before a remap. The 5th gen single pintle injectors are simple devices & not prone to blocking unless left for long periods unused. Good luck.

So plugs either fit or don’t they are the right thread length or not. Compare old to new. The plugs should have an alloy top screwed on to the top thread. That’s what makes contact with the plug cap. If a plug falls out of a cap there is something physically wrong. The runner boot does NOT restain the plug, the electrical connector does ! Plugs can crack & can create odd effects, but you can just swap them one at a time to test that. If the the gaps are wrong, why didn’t you check them at installation ? Plugs come with the gap set to something, but NOT always to your bikes spec, they are used on many engines, so ship with a common setting, but you should always confirm before using them that it’s right for your specific application ! Have ypu you checked the chain & sprockets ? Often a cause of apparent engine vibration on these bikes. If vibration is apparent when run on centre stand in neutral then it’s not the C&S ! Check all all electrical connections to coils & HT leads are secure. Hope that helps. PS Plugs are only designed to be fitted 3 times before the sealing crush washer is crushed flat & a seal is then not guaranteed. How are you fitting the plugs ? They should be hand tight using a plug socket plus 1/4 turn.

Well the small K&N when moved to the top of the air box in my big air box mod, added 5hp, the filter is NOT restrictive, it’s location is !

Some bikes use a form of factory dual stack now & others dual length. The problem with the dual length is they are really on/off not variable, but variable is very hard to do as there is always a step & the step disrupts the pressure pulse & also hurts the airflow around the circumference of the runner. At at some point this year I hope to try out a modified Throttle body & see if that improves things.

Yeah just needs some trimming of the 5th gen plastics below the handle bar where it meets the tank. Plus an adapter for tha rear mount. Have fun. Much simpler to just get a 5th gen tank, they are cheap as chips.

Yep correct, shorter makes more HP, longer more torque, these get the best of both worlds 👍😀

Well if you do it use a 190/55 the logical thought would be to use a 190/50 which are cheap as chips, but they would actually be a smaller diameter once fitted to a 5.5” rim. The 190/50 would slow the steering. A 190/55 will raise the rear by a few mm thus increasing the steering angle, but may still slow the steering due to the larger diameter & increased weight ! Try it & let us know the results !

So I was just re-reading this old thread, wow was it that long ago ? I forgot to add some good reference material, for those frustrated engineers. Old thread is here https://www.vfrdiscussion.com/index.php?/forums/topic/80640-yoshi-style-velocity-stacks/&page=3 Additional tech info here http://profblairandassociates.com/pdfs/RET_Bellmouth_Sept.pdf Which explains why I did this, the pulse bulges out of the open pipe/velocity stack end & the dual stack upper catches the pulse & carries it up its own pipe, hence the spacing between the upeer & lower is critical as demonstrated by HighSideNZ's adjustments. The calc for runner length is 84000/desired RPM for a result in inches, times by 25.4 to get it in mm. So 84000/9000=9.33” or 237mm, the 5th gen actual is 225mm (rough measurement by me) which gives peak torque at 8600rpm. So it’s a fairly close estimate for 4th reflection tuning length. Enjoy.

Only 3 for me, plus a couple of spare engines, that one day will grow to a full blown bike.