|
|
Post by 3tj6 on Jul 14, 2016 16:55:03 GMT 1
Hi all,Many years ago 87-89 i had a 350 lc that was bob farnham f2 tuned with swarbrick f2 pipes and 34 mm pj carbs , ypvs pistons , reed blocks,lightened flywheel and it was pretty quick . 25 yrs later i want to build something similar but using fzr 3tj forks wheels and brakes. Being 25 yrs later is that state of tune still ok? Or is there a more modern way of doing things ? Let me know ? Thanks in advance jon😉
|
|
|
|
Post by jon on Jul 14, 2016 20:11:17 GMT 1
Fitting the 3TJ rear wheel will be interesting in an LC.
I've been toying between a 3TJ and 3XV wheel in my latest build 'Yamaha hybrid 2', and it's very tight with the chain run to miss frame and tyre on YPVS.
An LC frame without spreading it, must be almost touching either side.
You'll have to have a wide swingarm too to take the disk offset from wheel centre.
p.s. Bob has tuned the barrels I'm using on this for midrange (as used in the YPM series where 60BHP is the limit, so why not give it more grunt).
Jon
|
|
|
|
Post by Mr Kipling on Jul 16, 2016 1:35:09 GMT 1
F2 as u say was an still is ( imo ) great , especially if u have shares in NGK !!! People tend to tune them for broader spread of power nowadays as its no longer about chasing the last hp ..
|
|
|
|
Post by mike0027 on Jul 16, 2016 2:42:11 GMT 1
|
|
|
|
Post by 3tj6 on Jul 16, 2016 7:56:43 GMT 1
Thanks for the info mike, yrs look great,as though yamaha intended😊
|
|
|
|
Post by jon on Jul 16, 2016 9:01:14 GMT 1
Mike, that does look good, and in black it's exactly what I was thinking of doing to mine (4HW) forks though.
Have you had the chain on yet to check clearance between the tyre and frame?
If so how much is there?
Also, what tyre section are you using?
|
|
Dave B
Drag-strip hero
Posts: 240 
|
Post by Dave B on Jul 16, 2016 9:08:38 GMT 1
Tuning techniques have changed radically since the 80's. Exhaust port shapes and timings are very different, and include "nozzles", "ski jumps" and extended tracts to cope with the transition from port window to round.
Timings are different, from the big ports and the long durations of the 80's to concentrating on blowdown time/area.
You need to talk to someone who knows their way around Engmod 2T.
Cheers
Dave
|
|
|
|
Post by mike0027 on Jul 16, 2016 9:29:50 GMT 1
Mike, that does look good, and in mars bar colours exactly what I was thinking of doing to mine (4HW) forks though. Have you had the chain on yet to check clearance between the tyre and frame? If so how much is there? Also, what tyre section are you using? Hi, The bike is almost finished, still got a few things to do like new pipes etc. Running a 160 rear wheel, Im not at home at the moment but will see if I can find a pic of the chain clearance.  The twins together.  |
|
|
|
Post by unrealedd on Jul 16, 2016 13:24:18 GMT 1
Lovin them bikes mate very nice pair, should be well proud nice job done.
|
|
|
|
Post by tell7437 on Jul 16, 2016 22:23:27 GMT 1
Is that a dt125 lc swinging arm fitted, never seen that in an lc before
|
|
|
|
Post by Mr Kipling on Jul 16, 2016 23:47:44 GMT 1
Is that a dt125 lc swinging arm fitted, never seen that in an lc before That's what I was thinking when I saw it , sure looks like a DT variant piece.. |
|
|
|
Post by mike0027 on Jul 17, 2016 1:37:29 GMT 1
As promised a pic (please excuse the dirt) of the chain run through the swing arm, there is still a lot that could be machined off the sprocket face if needed. Both sides of the sprocket hub have to be machined to get tit to fit, but that also means all the internal bushes have to be remade. In hindsight I should have used an RD125 swing arm as that does not have the rear footpeg mounting, but they are hardly visible behind the exhausts.  |
|
|
|
Post by jon on Jul 17, 2016 6:36:42 GMT 1
Mike, that sure is tight.
I measured my LC frame between the swingarm brackets yesterday, and it measured 201mm.
My 160 section tyre measured 160mm (not too surprisingly).
With the wheel central that would give a tyre and frame clearance of 20.5mm for the chain.
The 520 chain measured 18.5mm.
That means there is only going to be 1mm either side of the chain! Too little in my opinion.
Jon
|
|
|
|
Post by mannanan on Jul 17, 2016 11:24:35 GMT 1
Oooohhh ... that does look like a tight squeeze, what would you say the clearance actually is. Looks like you need feeler gauges rather than a steel rule.
|
|
|
|
Post by tell7437 on Jul 17, 2016 21:52:10 GMT 1
Mike is the 125 arm wider than the 350 at the wheel spindle?
|
|
|
|
Post by bare on Jul 19, 2016 3:35:27 GMT 1
Big Tires 'get girrlz ' or so twits think.
But In Real Life they just mess the handling.
|
|
|
|
Post by 3tj6 on Jul 19, 2016 19:48:21 GMT 1
Big Tires 'get girrlz ' or so twits think. But In Real Life they just mess the handling. dont agree with that ? U really think a lc will handle better on 3.25 , 3.50 x 18 than 120/70 160/70 x 17 🤔 No not having that??? |
|
|
|
Post by 4l04ever on Jul 19, 2016 20:32:37 GMT 1
I think bare is referring to oversize tyres on standard rims. Standard sizes seem to work best on standard rims.
|
|
|
|
Post by 3tj6 on Jul 19, 2016 21:15:04 GMT 1
Ok can agree with that , yrs ago people used to fit oversized tt 100's n kr 124's on the rear ! Dont think it helped?
|
|
|
|
Post by mike0027 on Jul 21, 2016 2:02:43 GMT 1
Big Tires 'get girrlz ' or so twits think. But In Real Life they just mess the handling. 160 is the standard tyre for that rim. |
|
