Jump to content

Slow burn 5th gen build - old skool kool!


Recommended Posts

  • Member Contributer

Quick update on the 5th gen Donkey: 


Dropped the oil after last month’s track day and to do three little jobs: 


- upgrade to VTR SP1 oil cooler (5 rows instead of 2) with slightly less corroded 5th gen tubes

- investigate why the clutch is slipping 

- possibly fit a Factory Pro shift kit


Cooler fitted with a new aluminium bracket I fabricated to move it a little more to the right (as you sit on the bike) and away from the fan. Hangs a bit skew but it seems to work so I’m calling it good. 



Couldn’t believe how corroded the lines on this 28k bike are. I swapped in the ones from my 70k bike because they were much better. Corroded one below. 


Then I decided to put a Samarium magnet on the sump plug to catch any swarf in the oil. Stupid - should have just bought one. But I did it anyway…


It’s a 6mm magnet so I drilled a 6mm hole with no wiggle room. The magnet will attract strongly to the recess in the bolt, but for extra security, it’s an interference fit. 



Punched it in the centre but drill wandered. Never mind - the swarf doesn’t care where the magnet is. 

Break out the torch to heat up the bolt and expand the hole, just enough to squeeze the samarium magnet in so it hugs it tight when it cools. 



Once the magnet is placed, a few love taps with a wooden hammer (careful, magnets are very brittle) to drive it home. 





And now the magnet snugly ensconced in the bolt - done! 

  • Like 1
Link to comment
Share on other sites

  • Member Contributer

So I finally opened up the clutch cover (and broke the gasket of course), to investigate why the clutch is slipping. Swapped out the centre bearing as a blind stab at removing that squeak I hear when clutch is released. It just comes out with finger pressure - easy! 




Weird because everything works out within spec. The springs are slightly down on new but in the middle of spec.

The fibre plates are almost up to new spec. Little glazing. 



Basket doesn’t have any pronounced notches. 

The steel plates are very slightly glazed, but not enough to explain the monumental slip (lasts a couple seconds) at 8,000rpm. 

Could this be an aftermarket clutch kit, maybe? The tabs on my new plates look different to the tabs on the old ones. 



Friction surface on the new ones looks more mottled than the old, but that could just be lack of oil. 

Steels look different too. New ones are smooth and old ones have dimples. 



Interesting aside: here are 3 x VFR 800 springs in order of firmness: 


1. Old 5th gen springs slightly worn

2. New EBC 6th gen springs slightly longer and stiffer

3. New Barnett 100lb springs for a Harley racer. Stiffest of all and slightly shorter



Going to deglaze the steel discs, install new fibre discs (although the old ones look great) and fit new EBC springs to see if they can stop the slip. 

What do you guys think of my discs, old and new? 

Link to comment
Share on other sites

  • Member Contributer

Typically if I have the clutch apart like that because I'm chasing a slip or verifying status of a new to me bike, it's not going back together without new fibers and springs.  I don't want to do the work over and now I have a known starting point.


I have found in the past that sometimes fibers are just "done' regardless of their thickness.  I almost always scuff the used metals a bit radially.


My new to me Hawk GT started slipping just in 4th or 5th under heavy load (38K original clutch).  I had the clutch cover off but the way the clutch is designed you have to remove the staked nut on the clutch basket to replace the disks.  I just popped in new EBC springs (which you can easily do) and it got me thru the rest of the season, but finally started slipping again.  New fibers and scuffed metals and it is now awesome.

  • Like 1
  • Thanks 1
Link to comment
Share on other sites

  • 2 weeks later...

Checking back in, really appreciate the quick guide on fuel tank re-keying. Easy peasy and with a good bit of cleaning with brake cleaner and some dry teflon lube (for my bike chain) the locking mechanism is working better than ever. Who knew pressing down on the cap would actually turn the key from unlocked to locked! Didn't do that before



Link to comment
Share on other sites

  • Member Contributer

Finally got round to replacing the clutch parts in the 5th gen Donkey. 

Fist (and hardest) job was to remove the old gasket. Took over an hour with a blade! 



Dipped the new friction plates into the old engine oil I’d just drained in the pan. Left them for a couple days. 

Whilst waiting, I treated the pushrod to a 3-stage polish. Swapped it round so the pristine end was pushed back into the engine and put a dab of Redline grease on the end. 


Here’s what it started out looking like…grim corrosion on the slave cylinder end. 

After a 1st stage polish…



After a 2nd stage polish. Closeup of the polished end shows scars from corrosion but couldn’t snag a fingernail on it…smooth. 



Now for a bit of flash and dazzle - buffed it with Tungsten Disulphide powder to make the surface slick and rust proof. Hoping it will make for smoother clutch action going forward. 


Had a new set of steel and friction discs on hand, but not the smaller friction plate that goes over the judder spring. The old one was within spec so I just scuffed the gloss off it with some 800, as per @BusyLittleShop advice: “Just enough to bust the glaze”. 


See how it’s glossy everywhere except where my thumb is. 



Then fitted all friction and steel discs as per manual. Followed by the slightly stiffer EBC clutch springs, progressively wound in a cross-cross pattern and torqued to spec. 




Final job was fitting the gasket, and to avoid breaking it in future I smeared a little copper slip on one face, and engine oil (from the drain pan!) on the other face. Should come off in one piece next time I open the cover. 



Once finished, I idled her for 5 mins to ensure there were no leaks (there were none, thank God!) and promptly took her for a 600 mile tour of Wales. 

What a ride. And not a hint of clutch slip either! 

Other than a slightly heavier clutch lever, she’s a dream to ride now. Power goes straight to the back wheel and rolling acceleration is fantastic. 

Big thanks to all those like @Captain 80s who kept me honest and didn’t let me cut corners. Costs a bit more but happy I did it properly in the end. 


  • Like 2
  • Thanks 2
Link to comment
Share on other sites

  • 3 months later...
  • Member Contributer

Got some time over Christmas break and fitted the front rad using horn mounting holes under the frame. 





It’s an F4i radiator with the lowest 3 rows (or maybe 4?) cut off to avoid front wheel contact at full suspension bottoming. I’ve got 125mm of fork travel on the ZX6R forks and the rad is 130mm away from the wheel and fender. 

Got hold of an oil cooler from an Aprilia Futura but it was grungy as hell (cheap!) so I boiled it for 20 mins to loosen the crud. Couldn’t believe how much there was. 



This is from the second round of boiling, after loosening it all up with a pick. 


Got to weld up a new exit takeoff as this one’s at the wrong angle, then find a suitable mounting position. 

The biggest challenge is finding a good front fairing solution for this bike. Got a garage full of experimental fairings and nothing seems to look right. 

I want a nice classic look with upright bars for comfort but can’t settle on a solution. All suggestions welcome! 

  • Thanks 1
Link to comment
Share on other sites

  • Member Contributer
On 12/24/2023 at 3:02 PM, Mohawk said:

ZX9R 👍

I like your thinking, Mohawk. 

Any other ideas? I was aiming for more classic than the ZX9R but it’s a cracking idea. 

Maybe even 1st gen VFR (or is that 2nd gen?). 

Or RC30 replica (but that means low clipons and a crippled back for this old man). 

Or CB1000 Bol d’Or…


Or something Mike Halewood might have raced.



Link to comment
Share on other sites

  • Member Contributer

NR750 Replica set. There was a guy on here or maybe VFR World that did one. There is a fibre glass set made by someone for a CBR900 so wide enough to accommodate your radiator! 

But required a lot of work to get it right. But was excellent in the end. 

  • Thanks 1
Link to comment
Share on other sites

  • Member Contributer

Thanks for your thoughts, chaps! 

Both those NR750s are based on VFR750s. Mines a 5th gen 800 so I’ve sent and email to Poly26 in France to ask if it’ll work. 

Three reservations: it’s a big-ass fairing (with a massive ass!); needs clipons under the top yoke to work; and what do I use for headlights? Still, I’ve asked the question. Hoping they’ll come back with a few other ideas too. 

Still looking at Ducati 888, 900SS and some of their cafe racer tackle. Or their ST2/4. 

Or VF750…or VF1000R (might be too big though)…or the Bol d’Or endurance racers…or TT racers if the ‘60’s…


Why’s this part so bloody hard? Chassis is ready to go - it only needs plastics! 

Link to comment
Share on other sites

  • Member Contributer
17 hours ago, Captain 80s said:

The VF1000F Bol d'Or could very well get the headlight in the right height/spot and give room for higher bars.



I like your thinking, Captain! 

In fact I’ve been lusting after that exact bike (rear has been chopped and that seat is lush). So much so I got some unobtainable fairings imported from Poland (couldn’t get any at digestible prices locally) and did a trial fit. 

Thing is, the VF is a much bigger bike than the VFR, so the fairing looks far too big. In fact with its narrow profile and compact wheelbase (comparatively) the VFR looks better with modern 600 fairings, instead of old 1000 ones. 

Have a look at these taken last summer: 


Hard to tell from the pics but the Bol d’Or cowl dwarfs the VFR considerably. It seems too big. But looking at it again now, it’s growing on me. 


Here’s an NSR400 (I think?), which I imported from China for a trial. Looks OK if you can imagine the screen in place. The screen on these is a nice classic bubble shape that allows high bars (all these have high bars). 



And here’s a VF400 fairing that I quite like but side panels will be a nightmare to match, as will the radiator scoops. 




Last one has CBR600 side fairings for trial and the previous two have 1st/2nd gen side fairings. And another with a 1st/2nd gen cowl for trial. 


Here’s a GSX1100 fairing for trial. Cafe racer style with high bars but I don’t think it works at all. 



Just to prove the point that our VFRs are quite small compared to old 1000’s, here’s a mockup of a 6th gen with CBR600 fairings. Not sure if the artist is using the correct scale but it looks about right. 


As always, your ideas are very welcome. No such thing as a limit - let your imaginations flow! 

Only thing I’ve not yet tried is the VF750, but my shed is really rammed with  fairings and I can barely move in it, so loathe to buy any more “trial” bits. There will be an almighty purge when this is all done!

Link to comment
Share on other sites

  • Member Contributer

For me, the best looking bikes have the top of the headlight about where a line would intersect extended from the top of the tank surface / angle.   Look at some of your favorite full-faired bikes and you might see a similar relationship.


That CBR800V4 faring would not be able to stay where it is with your bars.


Gonna be real tough to find the right combo.

  • Thanks 1
Link to comment
Share on other sites

  • Member Contributer
19 minutes ago, Captain 80s said:

For me, the best looking bikes have the top of the headlight about where a line would intersect extended from the top of the tank surface / angle.   

I like this. Will look to model the new fairing on this concept. 

Currently the existing fairing stay limits where I can trial-fit things. Should really pull it off for this. 

  • Like 1
Link to comment
Share on other sites

  • Member Contributer
48 minutes ago, Mohawk said:

Look up the Bio-Blade  a VFR800 running on methanol with CBR1000R fairings


Stray's bars would spoil any chance of putting that cowl any where close to that placement.  That's a big part of this latest discussion. 

Link to comment
Share on other sites

  • Member Contributer

Thanks for the input again, gentlemen. 

Mohawk, I think that’s a VTR1000 front fairing and CBR1000 rear. Does show that 1000cc fairings fit the VFR, though. 

And Captain 80’s is right about the high bars not fitting easily, although some VTR guys are trimming their fairings to fit Superbike bars. Anything’s possible. 

Here’s the perfect bubble fairing on a Firestorm but turns out it’s a one-off so can’t get it. 




Looks like a Ducati of some sort and can fit high bars, but it sits higher than Captain 80’s ideal of tank-to-headlight perfection. Would be much sexier a couple inches lower. 




Link to comment
Share on other sites

  • Member Contributer

I keep going back to that CBR650R fairing too.  The CBR800V4 rendering is based off of it I think.  


But, in real life like Mohawk's pic, the area for the bars (like at full lock) seems a little more open.  And with the headlights so low and angular, I think this could be mounted forward and high enough for your bars and still look the part too.


Worth investigating more I think.

Link to comment
Share on other sites

  • Member Contributer

This is the difference in using @SEBSPEED’s rearset adapters versus using the originals. The master cylinder is moved forward and I ran my brake line to the underside of the swingarm. Both help get the brake line away from the exhaust. And, it’s a cleaner, simpler look. 


  • Like 3
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...

Important Information

By using this site, you agree to our Privacy Policy.