Mohawk

AFAIK, there is NO difference between the US 48 state ECU's & the rest of the world for the 98/99 models. There is a possible difference for the 00/01 models as in Europe we got HECS-3 emissions kit for Euro2 compliance (not sure =if that was included in US models) & HISS ignition chip system for theft prevention. Synchronising your starter valves correctly improves the smoothness of the engine everywhere, especially cleans up the free revving nature of the engine. Gas mileage is hard to improve on the VFR its its one bad point. But on a stock setup 00/01 model you should get 200 miles from a tank, hits reserve around 185, even when ridden in a spirited fashion. When cruised you should get 200 before reserve. My tuned up version hits reserve around 160ish miles, but has reached 180+ when cruised on a eurotour through the Alps.

There's ya problem 🙂 Easy fix 👍 Avoid grease on the bar, attracts dirt then wears the throttle tube. Nylon throttle tubes are supposed to be run dry, they also absorb lube & expand which can make them feel sticky !

Hi Mohawk, Thank you for your donation of --. We look forward to improving the forums with your donation. Thanks VFRDiscussion

Unfortunately the electronic support circuits for each version are NOT compatible, so if you have a 4.2 version you have to buy a complete new MTB to get the 4.9 version !

Regarding single point wideband sensor, you don’t need to worry about front rear cylinder trims. The factory ECU map sends different trim values to the injectors already. IIRC the rear cylinders always run a bit richer than the fronts, to compensate for their warmer position and in the airflow. So if you use a single sensor you are adjusting both banks equally. To explain, let’s say at X rpm & Y throttle position the stock ECU sends front value 50 & rear value 55. Your internal or external (on dyno) AFR probe, decides you should have +5 added for the ideal AFR you have set the system for (13.2/1 for Dynojet, adjustable in RapidBike) , so all the injectors get a +5 signal added to the base ECU value, so the fronts now see 55 & the rears 60 ! So the offset trim values are maintained, regardless of which piggy back system you use. Hope me that makes sense.

Do a search for Bosch LSU 4.2 connector and/or 4.9.. The 4.9 is the latest, it uses a fixed reference circuit for a zero mark, where the 4.2 uses fresh air which it rarely sees in an exhaust. The 4.2 zero can drift over time, where as the 4.9 is electronically fixed, and it has a faster response time, which is better for a bike engine. But the 4.9 did not exist when the first MTB was designed ! If if you have a recent MTB which is not old stock it should be on the 4.9, as they were introduced about 2 years ago.

Looking good, I miss my old 500. Enjoy it :) Bad timeing weather wise is it not ? New rebuild, in the depth of winter, test ride with care.

Yes, MyTuningBike (MTB) connected to WideBand sensor. The new MTB support the lastest Bosch 4.9 sensor which is miles better than the older 4.2 that I have. I'll upgrade to one this year as I already have the sensor from when I was manually tuning the O2 before I added the MTB. The nice thing about the MTB is it corrects on the fly, you don't have to add its corrections to the base map, but you can. I did a trackday last year & was to noisy at 109.5db, so had to put a spud in the can, it passed noise testing fine, I was OK with this as the MTB would adjust the AFR to suit the new pipe configuration !

I got mine off ebay, advertised for a whole raft of Suzuki's but its the OD that matters. Measure the ports on your head, 42mm was the largest I could get in mine & the TBR flange is a welded on larger diameter tube. You can see the differences here between TBR on left in black & Motad on right. I had a the O2 sensor boss welded onto the TBR for wideband sensor use.

Updated version with everything in place 🙂

I finally got round to finding the drawing I did for someone a while ago, so here ya go. The shape of this intake duct makes it water free, I have ridden in some biblical rain & the bike never missed beat. If you look at where the air enters, it immediately hits the lower deflector plate, any rain would impact either the fly grille ove the inlet or the deflector plate. The bend at the bottom of the deflector plate has a couple of 3mm holes drilled in the bend to drain water & not shown is the oil cooler mount passes through the bottom of the forward protrusion/lip of the deflector plate, which also acts as a drain hole. Enjoy.

Hi Lance, I see where the problem is there. Not sure in the USA, but over here we have two types of exhaust gaskets. The cheap nasty things you have there which are square section metal coated asbestos substitute, or round section copper gaskets, which look like a bulls nose ring, thus the 42mm OD is the outside of a circlular edge. This gasket type is much thinner & will fully deform to fit the port, crushing from an original thickness of 5mm+/- down to 1.5mm & conforming to all irregularities. The ones you have are quite stiff & don't deform much, plus being square section they have to have a square section port to fit into ! Apologies for not making that clear, but I never use the square ones, I've had leaks with them in the past, so never even consider them ! 😞 The TBR has a very small flange lip compared to other systems, not sure what yours will be like, but worth considering the OD of the flange, has to fit the port obviously.

Distilled water is the best coolant, for maximum cooling from a fixed sized cooling system if it can be kept below 95c. Add anti-freeze in the required quantity based on your expected minimum temperatures. Remember the factory 50/50 distilled water to anti freeze is designed to cover the whole world, +50c to -35c ambient temperatures & it raises the boiling point of the coolant to around 106c. Round these parts its extremely rare to see -10c, so I usea 30% antifreeze to distlled water mix, which is good for -15c & my garage being built into the house means it never gets below zero in there & I don't ride the VFR in winter. So I get a better cooling ratio in the summer & don't have to worry when the bike is stored for winter. Choose your required minimum temp, minus another 5c just to be sure, so my expected minimum is -10c, so I choose -15c as an absolute safety margin. Alternately if you never ride in winter, use 5% antifreeze &/or water wetter in the riding season & just drain the system in the winter & refill with a high strength anti freeze solution for storage. Don't leave it empty as its likely to corrode ! ** Note - don't go above 60% antifreeze as the freezing point comes down again past this point. Pure antifreeze has a freezing point of -20c & is fairly poor as a heat transfer fluid, so you need the water ! FREEZING POINTS FOR SOLUTIONS OF ETHYLENE GLYCOL GLYCOL % BY VOLUME °F °C 12.5 25 -4 17 20 -7 25 10 -12 32.5 0 -18 38.5 -10 -23 44 -20 -29 49 -30 -34 52.5 -40 -40 For optimum cooling, it's best to use the smallest proportion of anti-freeze commensurate with your local temperatures and block materials. 10%-20% of anti-freeze will help prevent internal corrosion, especially when using an aluminum block or heads. For short term use, pure water has the best heat transfer rate of all.

I'll take the one in the middle, one of the best looking bikes ever made (IMO) pity that Honda cocked them up, but hey without that there would never have been a VFR nor geared cam drive 🙂

Hi Skids, unless they have changed the keys significantly then you just need a blank & most key cutters can cut the pattern. Likewise unless they have changed how HISS works, you can program spare keys on the bike from the primary keys. In fact you don’t even need a Honda chip key, you can buy the chips separately and insert I a blank key.