Not sure....................

[garry55]

where this fits on the forum.........................?

a 2 stroke Katana that's not a 50cc scooter...............

 

[Reinhoud]

Nice!!

[bluedog59]

That could turn out very cool. What s/arm is it ?

[garry55]

Yamaha TZR250 3MA - £20 in Japan - £60 by the time it got to me.

[badgerkdd]

It sounds like an interesting project, wherever it ends up

[garry55]

I'm thinking the really hard work is complete now. Fitting the GT750 motor into the 750 Katana frame has been a bit more difficult and involved than I had anticipated. Jigging the frame and motor to get the sprocket and swingarm centres aligned and the chain run spot on was straightforward enough..............................

getting the chain alignment right......

 but this off-set the motor so that the r/h exhaust port was fouled by the frame downtube. We sparked-up the grinder to make room for the header pipe.....

should fit now.........

 

 

 

[garry55]

we then pondered the best way to get the downtubes to clear the header pipes, without it looking too Heath-Robinson. This is what we came up with..........

an early GT750 "J" frame off Eblag for £30, which we introduced to the trusty grinder..................

then out with the old, and in with the new...........

some heating and tweaking.........

and that fits nicely.......

the down tube required the same attention........

and got it..........

spot on (ish)..................

tacked in place, awaiting final welding........

 

 

Edited August 15, 2016 by garry55

[garry55]

Had to wait until I had sourced a r/h front engine mounting plate before we could fit the other downtube.

After much heating / bending / tweaking, here's the r/h frame tube tacked in place............

Using the GT750 cradle enabled us to use the standard engine mounts too - and another bonus is that the radiator mounts are already in place.

the rolling chassis with motor..........

final welding and dressing of  welds next............

[bluedog59]

A very neat solution Sir.

[garry55]

why thank you Sir !

Edited August 15, 2016 by garry55

[completecaferacer]

very interesting  project, im building a gs500 with a gt500 engine in it

[garry55]

this is the final welding of the GT750 engine cradle tubes to the original Katana frame………….

I have now decided that I don't like the look of the rear footrest brackets / silencer mounts so they are coming off next - more welding required now...............

 

[Sheep]

Just come across this.....looks pretty cool..and different...i like that.

[garry55]

got a call today to say the rear footrest mount modifications were complete, so off I trots to Malton to collect the frame. The rear footrest and silencer mount have been removed, saving at least 10kgs of weight, and the front footrest mount triangulated so............

much neater - much lighter. 

Back home in the garage, I fitted the front and rear ends then test-fitted a spare motor to see if all the newly attached engine mounts lined up................

they did - perfectly Just the upper rear mounts to make now I can get the exact measurements for them.

Left-side footrest mount.........
  

sits just right and well away from the rear shock line - result

and the exhaust ports.............

clear of the frame tubes - just as Suzuki designed them to be.

[KATANAMANGLER]

@Rene EFE just gave me a nudge in the direction of this thread and now I  understand  why.  This is one to watch. It's really what we are all about.  

Ace

[KATANAMANGLER]

And in answer to the thread title's question; the project section would be as good a place as any but it fits just fine where it is.

[Swiss Toni]

Yup! Agree with all! Interesting and...different!  Keep up the good work!

[Reinhoud]

Nice project.

 

Tip; use a laser aligner to align/check the front and rear sprocket, it's the only way to do it right, you might think you it right, till you check it with a laser..

Clamp laser on the front sprocket.

 

When I rebuild my bike I aligned it with a piece of string, I thought I did a good job, turned out it was over a cm out.

[garry55]

when I was looking for a Sprint ST speedo, to compliment the Sprint ST front end (and make the wiring-in simpler) it turned out cheaper to buy a whole instrument console - only £40 plus postage off everyone's favourite auction site..........

included in the comprehensive display of instrumentation is this dinky electronic time piece.....

which I wanted to incorporate into the project - but where could I fit it without it looking like a cheap add-on..............?

here of course - into one of the accessory ports thoughtfully provided by Suzuki.......

a bit of measuring and drilling of 2 holes to accomodate the hour and minute adjustment buttons and......

it's in the r/h panel so at least I will be able to see it when the bike is at rest on it's sidestand 

 

[garry55]

the bottom shock mounts..........

to be used to convert the mono-shocked TZR250 3MA swing arm to olde worlde twin shock spec.....

So I set about locating the lower shock mounts onto the 3MA swing arm. The Gazi shocks that I purchased are 300mm between eye centres, adjustable to 310mm max. My ideal measurement is 330mm + adjustment, so the lower shock mounts would have to be moved nearer to the swing arm spindle.

First, I drilled a piece of flat bar with a 10mm hole (lower shock mounting bolt size) and a 12mm hole (top mounting stud size) at 330mm centres, then attached it to the top mounting and jacked-up the swing arm until the lower bracket sat flush on the arm, like so..........

I then sized and fitted the correct bushes for the shock mountings - Gazi shock sets include 4 of each of 3 different-sized bushings - 10mm, 12mm and 13mm.

with the swing arm still positioned at the 330mm height, I fitted the lower mountings to the shocks and attached them to the frame, thus.............

ensuring both lower mountings were sat flush on the swingarm, I took the measurement, both sides, from the trailing edge of the mounting to the end of the swingarm box section - exactly 141mm both sides - result 

The swing arm was now ready for a trip to my welder.............

Edited December 11, 2016 by garry55

[garry55]

and it came back looking like this...............

well pleased........

 

Edited December 11, 2016 by garry55

[garry55]

part of my "brief" for this project is to retain as many of the defining styling cues that made the original Katana's so different - and this includes keeping the instrument binnacle, usually replaced by Koso clocksets or the like.  So, having removed the internals from a (broken) set of Katana clocks, I set about fitting the Triumph speedo unit. Once mounted within the binnacle, it now required a new facia plate.

to do this, you need the original facia plate and some Blue Tac.........

a suitable material for the new facia (I used some Plasticard)......

a pen............

and a band saw helps too........

re-attach template...........

whiling filing away the night........

out with the compass cutter.........

just needs spraying and a couple of Katana decals and its done........

 

Edited December 11, 2016 by garry55

[garry55]

mounting the (Katana scooter!) 2T oil tank....

which is (mostly) hidden by the Katana's original electrics plate.....

on the left side. The right side required a bit more work.............

using the rear air filter section of a Katana 1100 airbox which has been attacked by a rampant hacksaw.......

and the bit I need, fitted in place, but yet to be cleaned-up - this will disguise the 2T oil tank on the r/h side of the bike.......

and help to retain the "standard Katana" look...........

Edited December 11, 2016 by garry55

[garry55]

been struggling to find a home for the battery, as it's usual place has been taken by the 2-stroke oil tank. But tonight, I had a Eureka moment, so it was out with the marker pen, drill and files..........

just a bit of cutting and grinding to do on the underside of the swing arm to get the battery box to sit flush

[Fazz711]

Looking forward to seeing more of this one