125cc Supermoto - 2 Stroke goodness

[binge]

150 main jet has improved it slightly.
Compression test came back at 115psi.
Gotta get a timing light on it.
And gonna order some smaller jets.
____________________
- Honda XL125S - CBR400 NC29 - VFR400 NC30 - CBR400 NC29 - TL1000R - TeeZeR Pit! - Bandit 12 - YZF450 - LuckyMX125 Pit! - Demon X XLR 140 Pit!
- Stomp KZ 160 Pit! - Demon X D-link 140 Pit! - CRF50F Mini-Pit - MonsterMoto 155cc MiniSM - Honda Chaly 150cc - Yamaha 98' R1
- Honda Chaly 140cc - Thumpstar 190cc 4v MiniSM - Aprilia RS125 Pit-Bike -

[Kickstart]

Hi

Compression is a bit low, but not enough to cause the issue you are having

All the best

Katy
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[binge]

Is the compression likely to improve as the engine runs in more?
It's a new piston kit in there on an old barrel.
____________________
- Honda XL125S - CBR400 NC29 - VFR400 NC30 - CBR400 NC29 - TL1000R - TeeZeR Pit! - Bandit 12 - YZF450 - LuckyMX125 Pit! - Demon X XLR 140 Pit!
- Stomp KZ 160 Pit! - Demon X D-link 140 Pit! - CRF50F Mini-Pit - MonsterMoto 155cc MiniSM - Honda Chaly 150cc - Yamaha 98' R1
- Honda Chaly 140cc - Thumpstar 190cc 4v MiniSM - Aprilia RS125 Pit-Bike -

[binge]

Somebody has told me on an RS125 page that my ignition is the 11kw version and I need the 21kw version to work properly with the 34mm carb. Is this utter tripe or likely to be the case?
____________________
- Honda XL125S - CBR400 NC29 - VFR400 NC30 - CBR400 NC29 - TL1000R - TeeZeR Pit! - Bandit 12 - YZF450 - LuckyMX125 Pit! - Demon X XLR 140 Pit!
- Stomp KZ 160 Pit! - Demon X D-link 140 Pit! - CRF50F Mini-Pit - MonsterMoto 155cc MiniSM - Honda Chaly 150cc - Yamaha 98' R1
- Honda Chaly 140cc - Thumpstar 190cc 4v MiniSM - Aprilia RS125 Pit-Bike -

[Kickstart]

Hi

On the 123 engine there is no separate cdi unit, and while there are a couple of coils that is more down to a change in production.

I have read somewhere that a generic Piaggio scooter cdi / coil can be used but never confirmed that.

All the best

Katy
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[binge]

That's interesting to know because the coils cost a flipping fortune!
To be honest, if it turns out to be an ignition problem I am just going to buy the inner rotor kit from PJME and lose the electric start.

Fitted some bobbins on the axles, and a speedo
Smaller jets wont be here until Tuesday, nor will the new carb needle valve, needle jet and clip. But will report back once they are fitted to see if there is any improvement.

https://scontent-lhr3-1.xx.fbcdn.net/v/t1.0-9/14095846_333058357045196_1740067223688050777_n.jpg?oh=3a58515df66e85d7abed943a310b4888&oe=584BDD6C

https://scontent-lhr3-1.xx.fbcdn.net/v/t1.0-9/14102667_333472507003781_4296216827233789544_n.jpg?oh=ae686b4ab78d865face777c2c1aa298c&oe=58456DAA

https://scontent-lhr3-1.xx.fbcdn.net/t31.0-8/14115491_333469663670732_8959946997959952976_o.jpg
____________________
- Honda XL125S - CBR400 NC29 - VFR400 NC30 - CBR400 NC29 - TL1000R - TeeZeR Pit! - Bandit 12 - YZF450 - LuckyMX125 Pit! - Demon X XLR 140 Pit!
- Stomp KZ 160 Pit! - Demon X D-link 140 Pit! - CRF50F Mini-Pit - MonsterMoto 155cc MiniSM - Honda Chaly 150cc - Yamaha 98' R1
- Honda Chaly 140cc - Thumpstar 190cc 4v MiniSM - Aprilia RS125 Pit-Bike -

[Kickstart]

Hi

Electrex World do a replacement stator and coil setup for the SEM ignition. Coil here:-

https://www.electrexworld.co.uk/cgi-bin/sh000001.pl?WD=sem&PN=CD5005_%2d_Digital_CDI_Unit%2ehtml#SID=675?aCD5005

All the best

Katy
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[binge]

Just road tested the bike properly since fitting the 150 main jet.
It's 100% an improvement, but I'm convinced there is so much more power to have.
I've just had a message from the guy I bought the RX125 spanny from, saying his bike had the same symptoms as mine, and then he sold the exhaust to me, and bought an Arrow system.

So, I've got a feeling, it might be the exhaust which is causing the lack of top end power.

It's been cut open, and had something done to it, and welded back up again.
I dont think I can be bothered cutting it back open, so just going to wait until i get paid, and stick a nice Arrow system on it.
Might look at Gianelli or Jolly Moto too, there are some nice pipes out there.

Crash bobbins have their benefits. Haha.
I just need to fit some fold up pegs now.


https://scontent-lhr3-1.xx.fbcdn.net/v/t1.0-9/14068087_333917643625934_5504060301281228685_n.jpg?oh=adfccc6fa344c858770865dbe45b65c5&oe=58508246
____________________
- Honda XL125S - CBR400 NC29 - VFR400 NC30 - CBR400 NC29 - TL1000R - TeeZeR Pit! - Bandit 12 - YZF450 - LuckyMX125 Pit! - Demon X XLR 140 Pit!
- Stomp KZ 160 Pit! - Demon X D-link 140 Pit! - CRF50F Mini-Pit - MonsterMoto 155cc MiniSM - Honda Chaly 150cc - Yamaha 98' R1
- Honda Chaly 140cc - Thumpstar 190cc 4v MiniSM - Aprilia RS125 Pit-Bike -

[Kickstart]

[Dimerz]

Not followed this too much, but all in all how much has this cost you so far? How was it getting it road legal and how long has it taken you?

[binge]

[Kickstart]

Hi

The stators are normally a sort of very dark brown type black. Coils are normally what I would call blue. I have never heard of different ones being used on 11kW bikes (and didn't the 11kW learner limit come in around the time the 122 engine came out - previously it was a 9kW UK limit).

All the best

Katy
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[binge]

Think I'm just gonna bite the bullet and buy an Arrow pipe.
If that doesn't sort it is will go to PJME for a racing flywheel kit.
And if it's still shit, then it's got to be a dog engine. 😂
____________________
- Honda XL125S - CBR400 NC29 - VFR400 NC30 - CBR400 NC29 - TL1000R - TeeZeR Pit! - Bandit 12 - YZF450 - LuckyMX125 Pit! - Demon X XLR 140 Pit!
- Stomp KZ 160 Pit! - Demon X D-link 140 Pit! - CRF50F Mini-Pit - MonsterMoto 155cc MiniSM - Honda Chaly 150cc - Yamaha 98' R1
- Honda Chaly 140cc - Thumpstar 190cc 4v MiniSM - Aprilia RS125 Pit-Bike -

[binge]

Got the bike TAXed and Insured today, and did about 10 miles on it.
Plug after a ride out was like so:

https://scontent-lhr3-1.xx.fbcdn.net/v/t1.0-9/14142040_334819596869072_2924925867420102911_n.jpg?oh=0cc972f46bfc35808bbe4d4d03e7d9d8&oe=584DDBED

https://scontent-lhr3-1.xx.fbcdn.net/v/t1.0-9/14088497_334819633535735_6893132833523523365_n.jpg?oh=6ebd65c920990691eb941bce49dc489a&oe=584625CB


I'm still running on the 150 main jet as the smaller ones have not arrived yet.

Getting to know the bike a bit. It does have a defined 'power band' but it's very short, sharp, and low in the rev range.
I don't think the gearing is too tall, I just think it is lacking top end power.
Slight down-hill decline, it will pull, and pull. Speedo tripped out at 65mph in 5th gear (Bicycle speedo, sensor cant keep up with the magnet).

But a slight up-hill, and it seems to loose steam very quickly, unless I knock it down a few gears and keep it really screaming.
I guess this is just part and parcel of riding a 2-stroke.

If I am riding along, at 30/40mph, about middle of the gearbox.
Roll off the throttle, and have it just on over-run, with slight opened throttle. it doesn't have get peaky and un-happy.
It behaves like a really cammy 4-stroke, and needs to be revved and kept screaming.


Still defo needs to make more power though. The old TZR would have handed it to the Rotax, easily.
I think I'd struggle to out-run a well sorted 70cc ped at the moment.
____________________
- Honda XL125S - CBR400 NC29 - VFR400 NC30 - CBR400 NC29 - TL1000R - TeeZeR Pit! - Bandit 12 - YZF450 - LuckyMX125 Pit! - Demon X XLR 140 Pit!
- Stomp KZ 160 Pit! - Demon X D-link 140 Pit! - CRF50F Mini-Pit - MonsterMoto 155cc MiniSM - Honda Chaly 150cc - Yamaha 98' R1
- Honda Chaly 140cc - Thumpstar 190cc 4v MiniSM - Aprilia RS125 Pit-Bike -

[Kickstart]

Hi

Plug is within reason.

Not sure what the gearing works out at with your wheels / sprockets. What did you finally settle on with gearing / wheel / tyre sizes?

With the power valve pinned open it should pick up quite hard, but with a power valve it smooths the delivery out a lot. But should have plenty of power.

All the best

Katy
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[binge]

I'm running 18:40 on a 13" rear wheel (130/60-13)
Its not as tall as an rs125 I don't think.

Just bought some retaining springs for my exhaust as I've just noticed the loops on the header.
I need to make some brackets up for the manifold bolts to attach the springs to.

Could it be pushing the exhaust away from the manifold when it's under load? Losing back pressure?
Although it would sound like it was blowing if this was the case?

Good practice either way.
____________________
- Honda XL125S - CBR400 NC29 - VFR400 NC30 - CBR400 NC29 - TL1000R - TeeZeR Pit! - Bandit 12 - YZF450 - LuckyMX125 Pit! - Demon X XLR 140 Pit!
- Stomp KZ 160 Pit! - Demon X D-link 140 Pit! - CRF50F Mini-Pit - MonsterMoto 155cc MiniSM - Honda Chaly 150cc - Yamaha 98' R1
- Honda Chaly 140cc - Thumpstar 190cc 4v MiniSM - Aprilia RS125 Pit-Bike -

[binge]

140 main jet fitted.
Brand new K57 needle and clip fitted.
Exhaust springs fitted.

Off for a hoon.
____________________
- Honda XL125S - CBR400 NC29 - VFR400 NC30 - CBR400 NC29 - TL1000R - TeeZeR Pit! - Bandit 12 - YZF450 - LuckyMX125 Pit! - Demon X XLR 140 Pit!
- Stomp KZ 160 Pit! - Demon X D-link 140 Pit! - CRF50F Mini-Pit - MonsterMoto 155cc MiniSM - Honda Chaly 150cc - Yamaha 98' R1
- Honda Chaly 140cc - Thumpstar 190cc 4v MiniSM - Aprilia RS125 Pit-Bike -

[binge]

Doing a bit of research, I see the RS125 runs on 16:39 sprockets? Is this right?
I am running 18:40.


So 16:39 has a ratio of 2.44
And 18:40 has a ratio of 2.22

Making my actual gearing, taller than a stock RS125.
But, then the RS runs a rear tyre, with a 24.1" Diameter.
My rear tyre has a diameter of 19.1".
That difference would bring the gearing back down.
Not sure exactly how much though.

Regarding the MX125 pipe I have fitted.
I assume these will give power lower down in the rev range, compared to the RS125 pipes, which are designed for top speed, aerodynamic bikes.

Could it be that my gearing is too tall for the setup I have?



I'm just getting frustrated with the thing that is all.
Down hill, this evening, I indicated over 70mph in 5th gear, just as I shifted up into 6th.
It then started to pull through 6th gear rather slowly, until I closed the throttle and shat myself at the speed wobble that was occurring.



I'm now running a 140 main jet.
The bike still revs okay. I'd say it's a little better with the new needle and smaller jet.
It's more responsive, less boggy.

I have a feeling it's using too much oil.
It's used nearly 500ml of oil, on only 8 or 9 litres of petrol.
That is less than 20:1.


Who is local to me (Kent), who has an RS125, or anything else Rotax powered.
Want to go for a ride one day, and have a go on it.

Either put my mind at rest and tell me that's how these are.
Or, tell me it's shit, and there is defo something wrong with it.

I was expecting a lot outta this thing, and I'm quite under-whelmed.



P.S. I've ordered a 16t front sprocket, just to give it more oomph from the go.
____________________
- Honda XL125S - CBR400 NC29 - VFR400 NC30 - CBR400 NC29 - TL1000R - TeeZeR Pit! - Bandit 12 - YZF450 - LuckyMX125 Pit! - Demon X XLR 140 Pit!
- Stomp KZ 160 Pit! - Demon X D-link 140 Pit! - CRF50F Mini-Pit - MonsterMoto 155cc MiniSM - Honda Chaly 150cc - Yamaha 98' R1
- Honda Chaly 140cc - Thumpstar 190cc 4v MiniSM - Aprilia RS125 Pit-Bike -

[binge]

https://scontent-amt2-1.xx.fbcdn.net/v/t1.0-9/14184399_335490550135310_8535778252411794977_n.jpg?oh=cb7f848319b4e42cbe4c0d10805c713f&oe=584E057C
____________________
- Honda XL125S - CBR400 NC29 - VFR400 NC30 - CBR400 NC29 - TL1000R - TeeZeR Pit! - Bandit 12 - YZF450 - LuckyMX125 Pit! - Demon X XLR 140 Pit!
- Stomp KZ 160 Pit! - Demon X D-link 140 Pit! - CRF50F Mini-Pit - MonsterMoto 155cc MiniSM - Honda Chaly 150cc - Yamaha 98' R1
- Honda Chaly 140cc - Thumpstar 190cc 4v MiniSM - Aprilia RS125 Pit-Bike -

[andyscooter]

have you got a tiny head or is the bike bigger then it looks
____________________
gilera runner vxr200 (chavped)
if its spelt wrong its my fat fingers and daft auto correct on my tablet

[Fin]

[Kickstart]

Hi

Oil pump is claimed to put out 0.9% to 2% equivalent, so 50:1 or less.

Think there are 2 markings on the lever for the pump. The one of those that needs less movement should line up with the mark on the pump body at the idle position.

Think your gearing works out at roughly 0.87 of stock gearing. Indicated speed an RS does roughly 100mph at 10000rpm, so roughly yours would be doing 87mph at 10000rpm.

All the best

Katy
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[binge]

It's a deceiving photo.

Here it is again, lent on my Transit Connect. it only comes up to just above the wheel arch.

https://scontent-lhr3-1.xx.fbcdn.net/v/t1.0-9/14224762_335919463425752_6148351865933883603_n.jpg?oh=f11cd471232e0682b2f820f4a438b5a1&oe=5845C9A4



Kickstart, I will have to re-check the oil pump, although I'm certain the cable is de-adjusted all the way, in order to make the 2 markings line up at idle. It wont adjust any lower.


16t front sprocket should be here today, as should my float bowl needle valve.

Will get them swapped over, and try again.


I also have this feeling I'm running it massively lean. Although cant explain the plug colour.

People running pod filters on the 34 carb are all running 180+ main jets.
____________________
- Honda XL125S - CBR400 NC29 - VFR400 NC30 - CBR400 NC29 - TL1000R - TeeZeR Pit! - Bandit 12 - YZF450 - LuckyMX125 Pit! - Demon X XLR 140 Pit!
- Stomp KZ 160 Pit! - Demon X D-link 140 Pit! - CRF50F Mini-Pit - MonsterMoto 155cc MiniSM - Honda Chaly 150cc - Yamaha 98' R1
- Honda Chaly 140cc - Thumpstar 190cc 4v MiniSM - Aprilia RS125 Pit-Bike -

[binge]

16t sprocket on.

https://scontent-lhr3-1.xx.fbcdn.net/v/t1.0-9/14202578_336496206701411_3747353548942416947_n.jpg?oh=2ce2f9f9c42ef710af49c36f177c40df&oe=583C48AC
____________________
- Honda XL125S - CBR400 NC29 - VFR400 NC30 - CBR400 NC29 - TL1000R - TeeZeR Pit! - Bandit 12 - YZF450 - LuckyMX125 Pit! - Demon X XLR 140 Pit!
- Stomp KZ 160 Pit! - Demon X D-link 140 Pit! - CRF50F Mini-Pit - MonsterMoto 155cc MiniSM - Honda Chaly 150cc - Yamaha 98' R1
- Honda Chaly 140cc - Thumpstar 190cc 4v MiniSM - Aprilia RS125 Pit-Bike -

[DottyDuck]