Another new guy! Help me!

Yeah - there are several significant differences between the '87/'88 and '88/'89 models . . . electrical and chassis.

For a start, the ignition picks up from different places. I think the earth wiring is different colours. The valve sizes are different, as are a couple of other engine internals. The forks, wheels, yokes etc are also different. There are also minor bodywork changes - the '86/'87 models had a three-piece front fairing; the '88/'89 has a four piece fairing. The windscreens are different and the front indicators are built into the fairings (or, at least, streamlined along the fairing).

I've got two classic bike articles on the subject which I'm trying to get into acrobat, but I've yet to find anything particularly useful online.

 

The basic question here is, can I use the whole electrical kit from an 87, or a 1990+ bike, on mine?

Sheesh, I don't even know if mine is an 87, or an 88-89. The chassis look identical to my eye.

 

No idea whether the electricals will work - or how to tell the difference between the engines without looking up the engine numbers. AFAIK, the engines look identical externally - as do the frames. What I can tell you is that the wiring is different between the '86/'87 and '88/'89 models because of the ignition pickup - but don't ask me what difference this makes overall.

Go buy a Haynes or Clymer manual. Haynes in particular should give you the engine/frame numbers and will also give you a wiring diagrams for the various generations in colour (Clymer rather usefully print theirs in black and white).

Alternatively, go ask a Honda dealer.

 

Bumppp! Hello from India again!

Well the electrical problem has been solved, to some extent. I've bought a wiring harness from each one of the model years, ie FG, FH, FJ, FK, off eBay UK, and I'll just have to try my luck with them.

I've been offered an older VF 750 as a parts bike. Planning to use the steering, front and rear suspension, wheel, tyres, brakes from that. What I'd like to know is, will the front forks/tree/whole front end bolt on to the VFR neck?

 

Front end - good question.

The single biggest hurdle you're likely to might to overcome is the steering stem - but it's not really that hard. Once you've taken the front end off your VFR (inc. yokes and steering stem) try the VF yokes and stem in the VFR frame. If the stem is the wrong length, you'll need to push both of the stems out of their yokes and push the VFR stem into the VF lower yoke.

There are a couple of other things that might get in the way - one of which is whether the steering lock stops on the lower yoke are in the right place (if they're not, grind them off with an angle grinder, work out where the stops need to be, and then either weld new ones on, or put a couple of bolts in the yokes at those points to act as new stops). The other major consideration is whether the new yokes/handlebars will come into contact with the tank. Unfortunately, the only ways you're gonna know are to find someone who has already done the conversion, or have a go yourself.

Good luck.

Neil

 

ooookay for what it's worth 1986+vfr750fg= cdi ignition with cam pulser driven from cam shaft
1987+vfr750fh cdi with pulser picked up from starter clutch
1988-89 vfr750fj-fk as above

86-87 mechanically identical in engine specs so engine map in cdi will work on both years
88-89 fundamental changes to cam timing so engine map in cdi will only work on these years.
If you can give the engine and chassis number i'll tell you exactly what you've got and what bit's you'll need to breathe life into your beast.
The forks you are thinking of using will cause many problems, ditch that idea and take the opportunity to use the cbr600 set up

 

Well, I don't have any of the VFR's cycle parts, except the cradle frame itself. So I can't put the VFR stem in the VF yoke. Will have to go VF all the way.

Ok, will look at the starter and figure out if it's FG or not. So you're saying that 86-87, though they have different pick-ups, will both work with the same CDI?

Don't have the chassis/engine numbers cos the bike is off the wreckers, and everything's been scraped off. Can't get a CBR600 setup either (I assume the F2), because bikes in India are bloody expensive and parts doubly so. A new R1 will cost you close to USD 20k, and it may still not be a wholly legal import. :frusty:

 

Fella

Sounds like you've got yourself some real challenges ahead.

Much as we'd all like to give you some definitive answers on which bits of the bikes are interchangeable, without any practical experience, we're as much in the dark as you are.

If anything, your best bet - and probably cheapest in the long run - is to get hold of one of the parts cross reference CDs available on eBay. That way you can look up the part numbers for various odds and sods to see what other bikes they're shared with. Alternatively, look on one of the online microfiche sites.

Looking at the MrCylces fiche site - www.mrcycles.com - the VF750 steering stem won't fit a VFR frame. The part numbers are different, and even though they're only a line diagrams, they look completely different. You're gonna need to make some major alterations to the stem you've got and there's no guarantee the stems will be the same lengths, let alone diameters. Do yourself a favour and get a stem from an FG/H/J/K model shipped out to you and save yourself the aggravation.

And more bad news; the CDI part numbers are also different between the '86 and '87 models. Doesn't mean the CDI's definately won't be interchangeable, but I wouldn't get your hopes up.

Sorry dude.

Neil

 

CDIs are different, that bit I've got covered because I managed to find 3 CDIs with harnesses.

Can I custom-make a stem? Like on a CNC mill or something?

 

The steering bearings are the same between vf and vfr part numbers are 91015 kt8 005, 91016 kt8 005 and 53214 371 010 so the stem diameters are the same, I cannot remember if the stem length on the vf is longer or shorter than the vfr.

 

As far as custom-making a stem, yeah, you probably can - someone made them for the factory, so it must be possible.

Whether it's cost effective or practical is a whole other matter. At the very least you'll need to work out:

- stem length
- stem diameter that fits into the bottom yoke
- distance between yokes
- diameter of stem between yokes
- distance between top yoke and stem top
- diameter of stem at top (will differ from the section between yokes)
- thread pitch and position of lower stem nut and upper stem nut sections

I refer to my earlier point about ordering one from overseas - without one to measure up, you'll struggle to get hold of the above details.

 

Ok, got the VF. Will sit and work it out. Otherwise, is the CBR 600 F2 the only one that plugs onto the VFR? Or can I use an F4i as well?

OT: VF is HEAVY. It's like wrestling with a bike. Damn thing refuses to lean in.

 

Another q: If I want to strip down and rebuild the engine, will a Haynes be enough, or do I need the Honda workshop manual?

 

stems

jamie dougherty is a member of this site contact him and get his thoughts on this he makes custom triple trees ,.