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General Category => FJ Project Writeups => Topic started by: dragsmart on September 14, 2013, 04:32:54 AM

Title: UK Drag bike rebuild
Post by: dragsmart on September 14, 2013, 04:32:54 AM
XS engine out and sold, FJ engine delivered and in need of a serious clean! was going to paint the frame but rather go with a lived not loved look, engine came with carb rubbers which saved some cash, have a nice set of flatslides to go on it,

(http://i256.photobucket.com/albums/hh163/mfcsince73/DSCN09841-1.jpg) (http://s256.photobucket.com/user/mfcsince73/media/DSCN09841-1.jpg.html)

no slave cylinder at present, but think I have found one from another UK FJ guy, will have to do a bit of imaganeering to fit it without the sprocket cover as I will be going with a 3" offset front sprocket to keep the engine central in the frame

(http://i256.photobucket.com/albums/hh163/mfcsince73/DSCN09861.jpg) (http://s256.photobucket.com/user/mfcsince73/media/DSCN09861.jpg.html)


am using an old set of FJ1100 cases as templates for engine mounts, hit a small problem as this frame was built around an XS engine and the xs sump pan is narrower than the FJ so sat 1.5" lower between the bottom rails, think I should have enough clearance without drastic cut and weld issues.


(http://i256.photobucket.com/albums/hh163/mfcsince73/DSCN09901.jpg) (http://s256.photobucket.com/user/mfcsince73/media/DSCN09901.jpg.html)
Title: Re: UK Drag bike rebuild
Post by: Havoc on September 14, 2013, 07:22:58 AM
Excellent, I shall be following this closely. My FJ engined Katana should be hitting the tarmac at Santa Pod early next year. What spec are you building the motor to? Keep up the good work :good2:
Tom
Title: Re: UK Drag bike rebuild
Post by: dragsmart on September 14, 2013, 02:04:53 PM
Running an almost stock motor with heavy duty clutch and a big shot of NOS,
Title: Re: UK Drag bike rebuild
Post by: fj1289 on September 15, 2013, 11:15:35 PM
Awesome!

Are you running the stock charging system or full loss?

While building my street tire drag bike, I was warned about transmission and crankshaft failures on FJs.  But noone ever specified the nature of the transmission failures.  Noone ever explained what caused rhe crank failures either -- over revving?  exceeding certain torque/horsepower levels?  stress from launching with car tire? etc.

What have you seen or heard?  I'd assume the XJ is very similar in those areas...

Good luck and keep us updated with the buildup and results!
Title: Re: UK Drag bike rebuild
Post by: dragsmart on October 19, 2013, 12:18:23 PM
xs was total loss system, gonna keep the alternator and starter on this build, keep it as simple as possible, looks like I have a few late nights in the workshop, i'm a farmer here in the UK so have a bit more time to spare during the winter.
Title: Re: UK Drag bike rebuild
Post by: Joe Sull on October 19, 2013, 05:23:59 PM
Thats a really nice looking frame. Leaning back in my arm chair, I probably would have bent the tubes were they come up from under the engine. I'm sure you've got good welds on heavy walled tubing though.
What a nice job. She'll be fun to ride!
Title: Re: UK Drag bike rebuild
Post by: dragsmart on January 22, 2014, 03:15:50 AM
FJ engine now in the frame,had a few welding and mounting issues but things a now moving fast, have our first race meeting with Straightliners at Santapod 20th march so set a deadline of 5th to have her ready, will post some pics soon
Title: Re: UK Drag bike rebuild
Post by: CatTomb on January 23, 2014, 12:28:03 PM
 (popcorn)
Title: Re: UK Drag bike rebuild
Post by: fj1289 on February 02, 2014, 05:26:11 PM
Quote from: dragsmart on January 22, 2014, 03:15:50 AM
FJ engine now in the frame,had a few welding and mounting issues but things a now moving fast, have our first race meeting with Straightliners at Santapod 20th march so set a deadline of 5th to have her ready, will post some pics soon

What?!  March?!  UK gets to hit the strip before we do in Colorado!

Seriously though - keep us updated on the build and the results!
Good luck!
Title: Re: UK Drag bike rebuild
Post by: dragsmart on February 18, 2014, 08:41:53 AM
engine is in, offset sprocket done, electrics next,

(http://i256.photobucket.com/albums/hh163/mfcsince73/20140218_134453.jpg) (http://s256.photobucket.com/user/mfcsince73/media/20140218_134453.jpg.html)

(http://i256.photobucket.com/albums/hh163/mfcsince73/20140218_134631.jpg) (http://s256.photobucket.com/user/mfcsince73/media/20140218_134631.jpg.html)
Title: Re: UK Drag bike rebuild
Post by: FJ111200 on February 18, 2014, 09:47:54 AM
Hey hey. 

Don't fire that engine up without the clutch slave bolted up.  :rofl:
Title: Re: UK Drag bike rebuild
Post by: dragsmart on February 19, 2014, 02:16:52 AM
no worries mate! have to machine the sprocket casing so the offset clears but also retaining the slave carrier, waiting for rear 530 5/8 sprockets, have had a few comments re the space behind the engine? this was a done so as to house battery/air shifter tank/nitrous bottle and all the electrics, don't think weight distribution will be a problem, I'm 6' 1 and 15 1/2 stone so the rear should stay planted, I like to call it even distribution!!!
Title: Re: UK Drag bike rebuild
Post by: Joe Sull on February 19, 2014, 08:02:08 AM
That looks slick! Those pipes are made for an XS 1100? or did you make them yourself?
Title: Re: UK Drag bike rebuild
Post by: dragsmart on February 19, 2014, 10:20:30 AM
well spotted Joe, pipes are modded xs11, just need to open out end pipe to run flush with lower frame rail, fitted the front end today, now time look at the dreaded loom.
Title: Re: UK Drag bike rebuild
Post by: Pat Conlon on February 19, 2014, 12:57:57 PM
A spin on oil filter will be at home on that engine.
Any thoughts on your clutch set up? That big meatball will need some special attention to hook up.
Title: Re: UK Drag bike rebuild
Post by: Joe Sull on February 19, 2014, 02:30:46 PM
I just finished re-installing my harness. You could lay a stock harness down the right side of the bike and plug it in for now.
Title: Re: UK Drag bike rebuild
Post by: dragsmart on February 19, 2014, 03:16:39 PM
hi Pat, running a Barnett heavy duty clutch, lets see how it copes, Hi Joe, the harness came with the road lump so gonna barstadise it and remove all the unwanted bits, "LESS IS MORE" as we say in the UK,  will post more pics asap
Title: Re: UK Drag bike rebuild
Post by: dragsmart on March 25, 2014, 12:00:50 PM
new rear sprockets 51t and 53t
(http://i256.photobucket.com/albums/hh163/mfcsince73/20140325_163627.jpg) (http://s256.photobucket.com/user/mfcsince73/media/20140325_163627.jpg.html)
(http://i256.photobucket.com/albums/hh163/mfcsince73/20140325_163516.jpg) (http://s256.photobucket.com/user/mfcsince73/media/20140325_163516.jpg.html)
Title: Re: UK Drag bike rebuild
Post by: Dads_FJ on March 25, 2014, 12:23:26 PM
umm... and you thought we wouldn't notice this?!

(http://i208.photobucket.com/albums/bb37/campsimonette/no2_zpseb649cb1.jpg) (http://s208.photobucket.com/user/campsimonette/media/no2_zpseb649cb1.jpg.html)
Title: Re: UK Drag bike rebuild
Post by: dragsmart on March 25, 2014, 12:26:52 PM
Nitrous bottle, air shifter is ally cylinder just visible beyond it
Title: Re: UK Drag bike rebuild
Post by: Joe Sull on March 27, 2014, 06:46:02 PM
(http://i1212.photobucket.com/albums/cc460/whiterabbit30/no2_zpseb649cb1.jpg)

Were on a need to know and we don't need to know, Ok I get it :scratch_one-s_head:
Title: Re: UK Drag bike rebuild
Post by: Pat Conlon on March 27, 2014, 08:02:13 PM
Joe, the first post in this thread shows the hairy Hoosier meatball going on the rear.

Me thinks he needs a stronger frame or at least more bracing...
When that rear tire hooks up, it's gonna twist that engine sideways.
Title: Re: UK Drag bike rebuild
Post by: ribbert on March 29, 2014, 05:39:18 AM
Quote from: Joe Sull on March 27, 2014, 06:46:02 PM
(http://i1212.photobucket.com/albums/cc460/whiterabbit30/no2_zpseb649cb1.jpg)


If you tire of building bikes, a career in computer graphics awaits you.
Title: Re: UK Drag bike rebuild
Post by: fj johnnie on March 29, 2014, 09:53:09 AM
 :rofl2: :yahoo: :yahoo:
Title: Re: UK Drag bike rebuild
Post by: andyb on March 29, 2014, 10:16:12 AM
Is it just me or do I see dual steering dampers on this thing? 

How come?  Expecting it to be that willing to go into headshake with that much rake?

Otherwise an interesting project.  I'm wondering how many teeth are on that front sprocket, I'm assuming the big rubber is taller than stock a pinch, but that seems to be an awfully big sprocket in the back, I'm concerned that you'll be out of steam by the finish line.  With a relatively stock (just the usual bolt-ons) motor, I found that crossing the traps around 8500 netted quite the gains vs going through with as much rpm as possible.  It's been awhile but I want to say that two teeth off the rear gave me about a tenth, and a noticable MPH bump.

What are you doing for electronics?  Two-step?  I know they work even with a hand clutch for some.  It seems to be begging for a slider, but that brings a fat lump of headaches aboard, like not being able to use the return road without a scooter giving you a push.  With the air shifter, a shift light, and a relay you could go full-auto on the shifts if you're looking for consistency, though you'd probably want to be able to still shift short on the button (just wire it parallel to the light output).

Interesting project, will be fun to see how it comes out.
Title: Re: UK Drag bike rebuild
Post by: Joe Sull on March 29, 2014, 08:15:04 PM
Quote from: andyb on March 29, 2014, 10:16:12 AM
Is it just me or do I see dual steering dampers on this thing? 



I know a guy that hit a dog doing sixty. Believe you me, he wished he had dual steering dampeners. :hang1:
Title: Re: UK Drag bike rebuild
Post by: dragsmart on April 21, 2014, 12:04:07 PM
clutch done with some degree of mods to avoid fouling offset sprocket, oil filter modded, carbs on, nitrous foggers fitted, k and n filters on, exhaust fitted and remounted, battery fitted, loom started.

(http://i256.photobucket.com/albums/hh163/mfcsince73/20140421_174253.jpg) (http://s256.photobucket.com/user/mfcsince73/media/20140421_174253.jpg.html)
(http://i256.photobucket.com/albums/hh163/mfcsince73/20140421_174307.jpg) (http://s256.photobucket.com/user/mfcsince73/media/20140421_174307.jpg.html)
Title: Re: UK Drag bike rebuild
Post by: Pat Conlon on April 21, 2014, 12:17:30 PM
ooooooh, THAT is gonna be fun....
Title: Re: UK Drag bike rebuild
Post by: andyoutandabout on April 21, 2014, 01:15:09 PM
Those hands have not been idle
Title: Re: UK Drag bike rebuild
Post by: Joe Sull on April 21, 2014, 04:37:40 PM
Looks pretty menacing. You got what looks like a muffler on there. I'm sure theres a good reason;

[] To loud
[] Increase back pressure
[] Track rules
[] Don't want to cause undo attention :biggrin:
[] None of the above
Title: Re: UK Drag bike rebuild
Post by: andyb on April 21, 2014, 10:17:21 PM
Quote from: Joe Sull on March 29, 2014, 08:15:04 PM
I know a guy that hit a dog doing sixty. Believe you me, he wished he had dual steering dampeners. :hang1:

I've hit a dog at 45... good steering geometry means that dampers are significantly less useful.



Bike is looking good!  Single disc front end?  Usually see them fitted to the left if there's just one, though I can't imagine it'll make that big of a difference.   Toss the air filters, and get the UNI's:  Better filtration means the motor stays tight longer, and you'll post the same numbers downtrack for longer.
Title: Re: UK Drag bike rebuild
Post by: Joe Sull on April 22, 2014, 05:50:33 PM
Quote from: andyb on April 21, 2014, 10:17:21 PM

I've hit a dog at 45... good steering geometry means that dampers are significantly less useful.


I'm sure the poodle would agree... (popcorn) :biggrin: