XBR replacement tank

[mthee]

Much appreciated. I probably wouldn't have touched the bike, had it not had the subframe cut by the previous owner. I was happy enough, until Timbo asked what was up with the banana seat that had replaced the original. I couldn't look at it again without seeing a banana-shaped seat. So, I cut it flat and was ok with it, until I clocked my reflection in a shop window and realised that I'd made the tank look humongous. I was originally just going to put a CX tank on, like JOOLZ, but then I saw a custom CB350 and liked the tank, so I got a cheap one off eBay. To get it to fit, I found that I needed to reshape (bash) the tunnel and bought the cheapest tank off eBay to practice on, which turned out to be the CB200 tank. With that sheer fluke and Michael's help, it all took off from there.
Unfortunately, the tank only holds 10L, but if I haven't managed to shag the handling, I'll probably try to make it go a bit quicker, especially as my motor drinks quite a lot of oil and needs looking at anyway.
On which note, Tommy, I see you have an XBR650 - how does it compare to stock - worth the upgrade? Any info greatly appreciated!😛

[tommy]

hi mthee yes its made a big difference that nx 650 motor has 660 hi compression  je piston and a cam in it so its a nice torquey motor and i have a 40mm mukuni carb on it  ,its apart for power coating now (getting over some injuries before i can get back to it) it also has 17" fmx650 wheels early fireblade forks and a 400 super four swinging arm it handles really nice  i want to keep the bike looking as standard as possible but xbr clocks look daft on the fireblade top yoke ,so bit of head scratching to be done there its all the fun of a project bike  tommy

 

[tommy]

when you put a nx650 motor in a xbr you have a few problems with wiring and the final drive ,but i used a nx 650 loom and the fmx 650 rear wheel runs a 520 sprocket which is the same as the nx ,the xbr has   a 525 but other than that its a handy swap over  tommy

[mthee]

Thanks for the detailed reply, Tommy. Your special sounds the biz! Are those engines hard to come by? I haven't seen any, or the easier XL600 barrel and piston to swap. It's one for the future, I hope, once I see whether she's a keeper now that I've got her looking ok. Let's hope she is a keeper, as I've probably devalued her with all the changes 🙄 Matt

[SteveC#222]

There is somewhere on the internet an article by the late 'Dr' Rod Gilbert on fitting the NX650 Domi engine to the XBR.  From memory he got around the gearing/finaldrive problem by using the XBR clutch basket and primary drive in the NX- apparently a straight swap. I'll see if I can dig it out if you're interested.

[xbally]

I think it was the late "Dr" Rod Gibson who used to do some satellite TV progs and edited Classic Mechanics mag after Bob Berry IIRC. I may have a copy somewhere.

[mthee]

Very interested, thanks for any info 👍

[SteveC#222]

I think it was the late "Dr" Rod Gibson who used to do some satellite TV progs and edited Classic Mechanics mag after Bob Berry IIRC. I may have a copy somewhere.

Quite right - my slip up! (nearly got it right)  

[xbally]

I think it was the late "Dr" Rod Gibson who used to do some satellite TV progs and edited Classic Mechanics mag after Bob Berry IIRC. I may have a copy somewhere.

Quite right - my slip up! (nearly got it right)  

Senior moment. I have them all the time!

Matt I'll have a look through my XBR archives.

[tommy]

mthee if  you do come across a xl600 barrel make sure its stamped with 591cc on it theres another one thats stamped 589cc thats  no use to put on  a xbr as its a different stroke  tommy

[tommy]

that late great rod gibsons article about the xbr /nx was in classic mechanics magazine sept 2001

[mthee]

mthee if  you do come across a xl600 barrel make sure its stamped with 591cc on it theres another one thats stamped 589cc thats  no use to put on  a xbr as its a different stroke  tommy

Noted with thanks. TBH, of the 2 approaches to gaining extra go, I think this is the one I would be able to afford.
In general, for this project bike malarkey to be really enjoyable, I think one needs an additional bike so as not to miss out on riding. Maybe I'll approach swimbo with this winning argument - lockdown laughs have been few and far between 😁

[xbally]

Matt-I've found a copy but not sure it's complete. I think I also  have the article on an XBR related computer disc . I believe I have an email address for you in my contacts list so I may be able to scan to you. PM me just to be sure. Martin

[mthee]

Received with thanks, Martin 👍😎

[mthee]

With the loom apart and simplified, I'm wondering how shot or not the 34 year old wiring is likely to be? Should I invest in new cable (and connectors?) or reuse what's there? Thanks.