New to forum, mods for a dio

[hughjass63]

Hi there from Australia. I have recently purchased a '93 AF18E Dio that has about 27k on it. Apart from some fading it is in very good condition and I am wanting to prepare it for my wife to use (and me if she'll let me).

We live in a very hilly area that isn't kind to small capacity motorcycles like the dio. So I am wanting to mod it just enough to:
1. have it cruise easily in traffic at up to 70km/h,
2. able to do at least 60km/h up long hills,
3. be able to beat cars from the lights,
4. and generally be safe transport.
5. I also need it to still be economical.

From reading many posts on this forum and checking on ebay, I realise there are many mods I can do and many extreme ways I can develop the Dio. But I am not wanting to race it, just have it reliable and relatively quick.

I am thinking of starting with a 80cc big bore kit, new belt, rollers and variator. I also want to keep standard carby and airbox if possible.

Am I on the right track? How do I know what weight rollers to put in? I understand that some people mix rollers. What does this do?

Any comments welcome.

Jon (Adelaide Australia)
PS photos soon.

[burnt_toast]

The best budget setup to reach those goals would be:

Stage 1
performance variator pulley
16x13 rollerpack
9:1 ratio gearing
1.5k center spring

With that combination your dio will do 45-50mph (70+kph) top speed easily, and have plenty of launch at stop lights. The stock dio cylinder bore is powerful enough to unleash more potential just by retuning the CVT transmission! Roller combination will help you tune for best powerband and the rollerpack will give you lots of options.

If you'd like even more power, you can do:

Stage 2
48mm bore kit
2k center spring
2k clutch grab springs

Then keep stock intake/carb/and exhaust and still get huge performance from a stoplight and uphill pull. You can also start with stage 1 then upgrade to stage 2 later to help split up funds.

I carry the above mentioned parts and can provide one on one support as far install and tuning

cheers
yan b

[hughjass63]

Thanks for the reply Yan, and quick! It sounds like you've been there with this sort of question.

Is it possible to get the performance without the gears? Eg, is there a way of using the rollers or a certain type of variator to gear it higher, or does one have to do the 9:1 ratio gears?

Also, the reason that I am thinking of the big bore, is that the present piston/rings seems pretty clapped out. The engine lags enormously when trying to take off but is okay when flat out (in the power band). It also does not seem to have enough power to go over 45km/h when going up long hills, but will do 60 okay on the way down. Also it has seized a couple of times when hot.

Thanks again.

Jon (going to sleep here in Adelaide, so maybe will hear from you tomorrow?)

[burnt_toast]

Thanks for the reply Yan, and quick! It sounds like you've been there with this sort of question.

Is it possible to get the performance without the gears? Eg, is there a way of using the rollers or a certain type of variator to gear it higher, or does one have to do the 9:1 ratio gears?

Also, the reason that I am thinking of the big bore, is that the present piston/rings seems pretty clapped out. The engine lags enormously when trying to take off but is okay when flat out (in the power band). It also does not seem to have enough power to go over 45km/h when going up long hills, but will do 60 okay on the way down. Also it has seized a couple of times when hot.

Thanks again.

Jon (going to sleep here in Adelaide, so maybe will hear from you tomorrow?)

Indeed Jon, I've worked with the Dio platform for a long time myself and have always tuned for budget friendly, yet powerful and reliable builds

As far as the variator, even with performance one you will cap it out at about 40mph (64kph), without a gear upgrade, while revving engine to max. And also if you upgrade the bore you will be revving out of the powerband at top speed since you run out of stock gearing very quickly.

I've found the 9:1 ratio gears ideal for a great launch and cruising smoothly without revving out and stressing the engine. And at your mileage I would try to take it easy on the revs So basically bottom line is I'd highly recommend a gear change for long term reliability.

[evilone]

The aftermarket variator will help some but the gears are highly recommended.

Also, the reason that I am thinking of the big bore, is that the present piston/rings seems pretty clapped out. The engine lags enormously when trying to take off but is okay when flat out (in the power band). It also does not seem to have enough power to go over 45km/h when going up long hills, but will do 60 okay on the way down. Also it has seized a couple of times when hot.

I'd do a compression test first. It sounds more like carburetor problems to me, maybe needs a cleaning. I see you said it seized a couple times when hot, leads me to believe too small jet or build-up on jet not letting enough fuel into carb. Fuel cools the cylinder. Start with a real thorough carburator cleaning (follow procedure under technical documents) and use a gallon dip tank, let it sit overnight (only put metal parts in tank )

[evilone]

Oh hi Toast, i was typing advice at the same time

[burnt_toast]

Oh hi Toast, i was typing advice at the same time

hi2u2

[Wheelman-111]

Greetings:

You can read about one modding sequence with a similar scooter here:

http://www.hondaspree.net/phpBB3/viewto ... 16&t=10555

Bee-Tee's advice is spot-on. He's a trustworthy source of information and parts for your bike. The stock bore has the juice to drive the 9:1s to 80KPH if it's healthy and you add a variator and perhaps a larger rear tire. Uh, sorry... Tyre. A BBK is a good plan if the compression's going South. Um, sorry... North if you live Down Undah! For sure you need taller gears than stock, if the AF18 is 12:1 like the AF16E.

Burnt might advise you to get 9:1s for the BBK, but if you plan long downwind/downhills at top speed, I recommend 8.4:1s instead. Otherwise the BBK has too much power, not enough drag at the 58MPH/95KPH limit. It can overrev and overheat. Hillclimbing won't be an issue with the BBK.

Stock air box and carb jetted to low-to-mid-90s will work fine with a stock pipe. With a conservative aftermarket pipe you may wish to jet up as high as 110.

Good luck!

[burnt_toast]

just to add info to the gearing part wheelman mentioned:

a properly balanced and geared cvt will not overheat normally, what this means is that with 9:1 gearing you run heavier rollers, and keep engine revs down to balance things out. with 8.4:1 and same bore setup you would runn lighter weights for revs and again balance.

I have 9:1 installed on my daily driver bumblebee 72cc Contessa powered Elite and have not had any issues with over heating or overrevving while climbing or descending any hills. Over 4000+ miles worth of test and tune miles on that setup and its capable of 65mph, which I've hit on plenty of downhills.

If you want 60+mph smoothly then 8.4:1 is better bet, but that doesn't seem like the goal for hughjass63 lol

[hughjass63]

I'd do a compression test first. It sounds more like carburetor problems to me, maybe needs a cleaning. I see you said it seized a couple times when hot, leads me to believe too small jet or build-up on jet not letting enough fuel into carb. Fuel cools the cylinder. Start with a real thorough carburator cleaning (follow procedure under technical documents) and use a gallon dip tank, let it sit overnight (only put metal parts in tank )

Thanks for all the feedback guys. Very much appreciated.

From other reading on the forum I decided to pull apart and clean the carby with compressed air, although I do not yet have any carby cleaner (what is it made of?). The main jet is definitely clear, but on reassembly the problem still exists. I checked the plug and it seemed to have a reasonable brown colour, but I was not too convinced. I forgot to check the jet size when I had the carby off, but will pull it off again and test a larger one.

When I got the bike it had no filter element in the airbox, so I put in a standard Honda foam one as someone advised me not to put on an aftermarket filter.

I also read on another thread about drilling the standard airbox with another hole. Is this true for the Dio or was this for one of the af16e or other engines?

[hughjass63]

Greetings:

perhaps a larger rear tire. Uh, sorry... Tyre. A BBK is a good plan if the compression's going South. Um, sorry... North if you live Down Undah!

Yes, larger rear tyre is part of the plan. (we also spell 'jail' as 'gaol' and use a lot less x's and z's in our words than Americans do. We Australians believe X's and Z's are only for special occasions ). Also, in Australia our compression does still go south - it just goes around past the south pole and then back up the other side of the globe.

Back on topic, sounds like gears are now part of the budget. Thanks again for the advice.
- Jon

[Wheelman-111]

Greetings:

Quoth Jon:

Yes, larger rear tyre is part of the plan. (we also spell 'jail' as 'gaol' and use a lot less x's and z's in our words than Americans do.

But you also waste an awful lot of "U"s! (I have a nephew on the Gold Coast whom I also like to tease...)

Back on topic: Belabouring the point... , 9.1:1 gears provide better initial take-off than 8.4s for beating cars from lights.. Both hillclimb well enough with a big-bore and match-tuned vario.

However compared to stock (AF16) 12:1s, 9:1s lower RPM only by a factor of 25%. If it is true as Yan suggests that stock gearing maxes at 64KPH, then any speed gain above 80 must come from increased RPM.

On my Elite, 97KPH (on GPS) occurred at well over 9500 RPM using 9:1s. Yan says his Italian-cylindered 72cc can hit 107 with 9:1s, and I believe him. But math is math. At top speed, no matter which rollers you install, the variator exits the speed equation once it maxes out at 0.8:1.

You can work out the Speed/RPM graph yourself using that factor applied to the gear ratio times the tyre circumference.

Unless you're prepared to back off at WOT and on downhills, a Big-Bore kit needs lower gears than 9s. Do yourself a favour and learn from my errour.

[hughjass63]

Thanks wheelman. Your grief induced advice is gold for this shoestring soul. I'm sold. 8.4:1 it will be. Variator and bb kit to follow.

Tomorrow I will chase up a bigger jet to see if I can get present tired (note I didn't say 'tyred') piston and rings humming again while I wait for upgrades.

I am torn in two directions at the moment. I am just finished rebuilding a previously damaged '05 Honda cbr1100xx superblackbird (160hp, 300km/h) and putting it on the road... and am gearing it down for the very opposite reason than am gearing up the dio. Once I put it on the road, hopefully sometime next week, the dio will be the next expenditure.

And that brings me to my moment of confession. I didn't buy the dio as previously claimed... I found it on a hard rubbish pile. I had dropped my kid off at school and was coming home and saw a headlight poking out of a pile of old washing machines and broken cupboards on someone's front lawn. I went back, and it was a dio covered in dust, ripped seat, no keys, and flat tyres. As I was on holidays (if nothing else, I thought) it would be a bit of fun to fiddle around with and maybe convert into a kids minibike or a chainsaw or something.

Then I started cleaning it, and it came up really well. I hooked up a battery, hit the starter, and within a few seconds it started! And idled! I hadn't even put fuel or oil in it! Then I rang the South Australian rego, and found out it was very easy and cheap to rego. My wife then saw my partially restored project and staked a claim on the scooter, saying it would be great for getting her to uni (oh, sorry... 'college'). Thus my present endevour. It needs a new front tyre which I will probably swap with a big one for the rear. Also needs battery, lock set (I broke the present set to get it going), air filter (done), rear brake cable (done) and a fair bit of TLC (mostly done). A friend has just offered to reupholster the seat, in the original turquoise, no less, which is the orginial DIO SR multi colour scheme, so it will soon look great.

Anyway, there it is. I now own both the most powerful and least powerful hondas on the planet.

[burnt_toast]

I'd hardly call a dio least powerful LOL

a spree or an express, lots less powerfull than <<< stock Dio

[hughjass63]

Sorry, I should have qualified that. The dio being one of the least powerful hondas in stock form. PS - have you ever ridden a stock honda 4 stroke 50 scooter? I had one as a teen and it truly was the least powerful bike I have ever ridden.

What is so compelling about the dio though is the potential. Soon after I started my project I checked out dio racing on youtube and was stunned by the speed and seriousness of the racing. Not quite European 50cc GP level, but not as far off as one would think.

Then when I saw how affordable and plentiful were dio bits, and how enjoyable it was to ride... I was hooked.