Why the hell I bought it I'll never know! Katana AY50WRW Project

Just a footnote for you Scooter-Noob, you're a rotten sod putting that idea in my head, now I have to go out to the workshop and check. I couldn't sit here otherwise, be thinking about it all night.

 

Right. Back again. Just looked at both rear pulleys, holding them both fully open against spring pressure there may be about 1mm difference in opening. I don't think that could be the problem; however saying that I shall still swap them over tomorrow and try.
Spring pressure; spring pressure; now there's a thought.....................

 

What the Hell!!!!!!!!!
I've just been looking around for a new variator and come across this: I have high-lighted the relevant section referencing the cdi:

Suzuki Katana Ay50 Race Tuning Guide


One of the earlier race inspired scooters by Suzuki, featuring upside-down Showa forks and Carbon fibre look dash panels, the Suzuki Katana was an instant hit and speedily became favorite for tuning, with plenty of carrying out race parts from Malossi and numerous other manufacturers.

​

Early Suzuki Katana's had the Suzuki air cooled machine in them, whilst later Suzuki Katana's had Suzuki's new liquid cooled engine, and where designated Ay50R for the race output version.
Motorcycle Parts Suzuki

One preponderant feature of the Suzuki Katana's are their very low gearing, which means the machine does more revolutions per wheel revolution compared to other scooters, this provides very quick acceleration but a lower top speed, even on tuned engines, most other derestricted scooters can keep up on top speed, but will struggle to match a race tuned Suzuki Katana on shear acceleration.
Suzuki Katana Ay50 Race Tuning Guide
Although some population see the Suzuki Katana's low gearing as a problem, it is also the scooters most strength, with blisteringly fast acceleration, most other scooters will struggle to keep up with it in an urban environment, as even when others are tuned and kitted up with carrying out parts they'll still struggle to match the Suzuki Katana's 0-30 times. When the liquid cooled Suzuki Katana is tuned it is roughly untouchable against all the other 50cc scooters on the store in these times, it'll only loose out on longer roads where speeds of 50mph+ can be achieved by other Lc scooters.
The Suzuki Katana's are primarily restricted mostly in the exhaust, so in the very early models it requires binning and replacing with a race exhaust, whilst in the later versions with a 2 part exhaust, you can grind out the internal restrictor cone and refit the exhaust, although nothing will match the carrying out that an aftermarket race exhaust gives for the Suzuki Katana. On the very early models, the Cdi is also restricted and requires replacing with an aftermarket model, although this isn't a problem on the later scooters.
As with my usual reccommendation, Gianelli Exhausts commonly make the best carrying out exhausts for scooters, and since they're all e-marked, wholly road legal and come with a warrenty when fitted by an authorised mechanic, so are by far the best tuning selection for road going Suzuki Katana's, and all other scooters that are being tuned for the road.
When fitting a Gianelli race exhaust to your Katana, it'll wish a slightly higher jet (0 to 2 sizes on non catalysed Suzuki Katana's, I don't think they made any with catalytic converters) and slightly lighter rollers, since carrying out exhausts allow the Katana to make more power but at a higher rpm. Going 0.5 - 1 gram lighter than appropriate commonly does the trick for Gianelli race exhausts on the Katana's, but it varies in the middle of exhausts and tunes, and the Suzuki takes 17×12mm rollers.
After fitting a race exhaust, the biggest benefit the Scooter Katana will gain is by fitting a carrying out big bore kit, adding a 40% growth in capacity and more than doubling the power. Malossi and Polini make the best big bore kits available for tuning the Suzuki Katana, and will supply the best carrying out and reliability compared to the economy big bore kits on the store . As you're expanding the capacity with the big bore kit, a bigger jet is required to be fitted in the carb, regularly colse to 6-8 sizes larger, although doing a plug chop after a test ride to check the jetting is recommended to check your scooter isn't running lean after it's tuning, otherwise it can be liable to go bang.
When tuning your Suzuki Katana, it is important to make sure you run it on the best potential fully artificial oil, especially with the Katana's oil pump system, as it can be prone to clogging up the exhausts, especially the appropriate ones. This is one of the reasons why fitting an aftermarket race exhaust to these scooters can supply such a huge divergence on older models.
After fitting the Gianelli race exhaust and tuned big bore 70cc Malossi cylinder kit, you'll have a exceptionally fast accelerating scooter, but without an overwhelming top speed growth compared to other scooters, due to the Suzuki Katana's low gearing. You can now either keep the fast acceleration, or sacrifice a minuscule and fit a gear up kit to your Katana, allowing it to use some of this new found power provided by your Malossi big bore 70cc kit to give you a great top end, good for other 10mph in most cases. Although it looses some acceleration by fitting a gear up kit, your scooter will still be faster accelerating than a appropriate untuned Suzuki Katana, so don't think a gear up kit will make carrying out worse than before.
For even higher increases in power, bigger carbs and aftermarket variators are available, but do not make as bigger differences as the Gianelli race exhausts, the Malossi big bore 70cc kits and the gear up kits. The variator will supply a large benefit if it is fitted onto a Suzuki Katana that is older and has done a lot of millage, as this combined with a new belt will give a lot smoother acceleration and a minuscule top speed increase.



Somebody, somewhere, pleeeeeeease! explain to me. is it or isn't it restricted? The CDi?????????

 

no cause it says the earlier ones were aircooled and cdi restricted and the newer ones were liquid cooled and as its the newer one its not restricted through the cdi ' i think

 

still for £20 i would try it

 

here is a second one to play with your head do you have the right size belt

 

Yeah, belts the right one, as for the cdi, did try that. After speaking with PMT and AP i swapped out the other one from the 53 plate. It's an aircooled engine but from what I can gather they are the same, both Ducati cdi's. No difference either way.
I did spot on fleabay an electrical resistor from a katana, not sure what year now, that got me thinking.
Then again, I'm thinking I might as well just sell it as a running, taxed and mot'd 50cc scooter suitable for a 16 year old and let them deal with the restrictions and spend their money on it. Got enough things to get on with and to be honest this is done and ready to go.

 

Dude, unbelievable. I really gotta get my eyes tested. Just measured trhe belt again. Too friggin big man!!!
Just dropped one on for a honda, only 7mm shorter in length but same width and depth as standard katana,
37mph!!!! Off to AP to do some shopping now.

 

OK. Happy now. Apart from waiting for the new lower panels to arrive, its done. Averaging 37mph on the flat, 40+ on slight downhills, and steady 35 up.

 

what was it in the end?

you should still get 45+ on flat out of a yamaha

 

Soddin belt! Too thick. When i measured it I thought it said 16.5mm, it wasn't. It was 18.5mm.
Friggin eyesight. Happens when you get old. Too thick equals can't get to the bottom of the clutch pulley. Took one off a honda engine I have on the shelf and bingo!
Have ordered 2 new belts and 2 sets of rollers, one set for this one and one set for the other katana I have yet to start on.

 

yep well i know about the bad eye's

 

dunno about 45 on the flat though. once this gets over 40 I'm thinking the revs are awful high. Gonna see what the potential new owner thinks on monday but might put a 15 to 20% gear up in it. Just to decrease the top end revs a bit. BTW the potential new owner is 44 so he aint gonna thrape it

 

you cant gear up a 50cc, you may just need higher rollers weights to bring down the rpms a little

 

You reckon? Considering the Katanas already low ratio gearing as standard?

 

100% 50cc can not pull a gear up.

99% or all scooter have a gearing that can hit 59mph there is no reason to think the Katana is any different.
dose the bike have an RPM gauge? the stock 50cc head can go to about 9,500 rpm's so what you think is over rev my be fine.

now you have changed so many parts getting the bike to move why not tell us the full set up you have an we can advise on roller and clutch springs, some ppl confuse the need the harder clutch springs with the need for lighter roller and that will drop the speed you can get to.

 

Greetings again,
Just come in from the workshop today, another 9 hours gone like it was never there
Got the gearbox all back in and the ancillary stuff back on, gonna have to repaint the sump plate though after I cleaned off all the crap from the last 4 years it is now bare; self colour; cant have that, not on my bike.

Anyway, back to the Katana.
My train of thought is because the katana is low geared anyway and gives a fantastic take off thrust, by giving it an 11% gear up it shouldn't affect the initial take off that much but would put it more in line with the other normally geared peds, and also reducing the top end revs at the same time.

Have ordered a new belt and 7gr rollers yesterday, mostly because it needs a new and proper belt anyway and the current rollers are starting to get little flats on them.

The setup on this scoot is completely standard except for the Leo vince exhaust with 5gr rollers and a marginal up-jet to the standard carb.

And it doesn't have an rpm gauge.

 

Why would you jump from the 5g rollers fitted to the 7g your ordered over 6 rollers that a 12g jump that is a hell of a lot. with a leo TT, you would drop about 1g over stock on roller and fit one step up on the clutch springs.

you bike as a MORINI 50cc SUZUKI AIR COOLED ENGINE it is not low geared compared to any other scooter. it is common for ppl the claim gearing is a problem when there bike is slow, the problem is the set up. it sucks nuts but you will probable spend around £40 on rollers before your spot on. the stock veriator will not be helping.

i problem you will have is there is not a lot of stuff out there for you to get. go to the dredded pedstop seb site (that i love) they sell a polini veriator that would be 100% better

 

Yeah, looked at it yesterday. But i'll leave that to the new owner, I'm taking the bike over tomorrow for him to try. He already likes it, but he is taking into consideration that he is 44 years old and 18 stone in weight. It's not going to be a problem, I sold him a sym jet euro x 18 months ago and he went great on that. Had it back off him and sold it the same day, made £50.
I digress, no 5gr rollers in stock at my suppliers hence the 7gr order.

 

that will be a big problem for running with an 18 stone lad on it, BUT best of luck