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Discussion Starter · #1 ·
Hello all, i just joined this forum, in hopes i can get some guidance, i have had this cagiva planet for a little bit less than two years. bought it in quite rough shape, and i have been getting her back in shape.

Now, the other day, i turned on the key, and didn't hear valve check sound, so i started checking, when i noticed the kokusan controller had a hole in it, with strong burned electronics smell, yes, its completely toasted. so ive been wondering a couple of things.

-how good or bad does it works without the valve(or with it constantly open)? i read you can just lock it into open position, what's the best way to do this?

-has anyone tried the pneumatic valve kit from "italkit"?

-is the zeeltronic really worth the high pricetag? and can i get that to replace the fried kukusan unit?

-is there any other alternative?

thanks
 

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Zeeltronic is only option if you have a kokusan ignition (very small CDI)

I would not advise on the italkit PV. And I think you need to drill the cylinder for it. Not advisable while its on the engine.

You can lock the PV in either position by manually rotating the CTS controll motor. Hoe much you lose is best observed by you. It depends on pipe (exhaust) you have.

If you are deciding between zeeltronic and italkit and budget is a problem than by all means its Italkit. Or no valve is also an option.

For zeel you need to find out the reason for failure of CTS (PV) controller. As PV motor can draw a lot of power, a stuck valve in the cylinder will burn the CTS controller. Never bikes came with a fuse on it to protect the Controller from such high current.

If you have crazy good luck maybe only a transistor or diode has failed and might be worth giving it to an electronics specialist to try to repair it (if its cost beneficial)
 

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Discussion Starter · #3 ·
im mostly concerned about how the italkit performs, i have used pneumatic valves in older 2strokes, but seems this kit is kinda new, and cant seem to find much info on its performance.

i opened the valve controller, andseems completely destroyed, i took it a specialist anyways, but i dont think it has a solution, (i will upload pics later)

took the servo and it seems to be stuck, this kind of servo is similar to the ones used on some ducatis (i work on them mostly) and using that as a reference, it seems to be really hard to move, so my suspicion is some problem with the servo, which caused the problem, i will disassemble it this weekend, and asses the state of it.

currently, i just did a quick test with the valve on its fully opened position, and yes, it does loose some bottom end response, mid end doesn't get such a big hit, and ofc, at top it works normally. altho its much more agressive now. i will have to ride it more to make a full judgment. but considering that experience, if the italkit actually works, maybe its enough of an improvement, in case the electronics are beyond repair, because getting spares here, its almost impossible.

if not, i will have to make a controller myself, probably using an arduino and some solenoids, but would require time i dont have currently
 

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Servo is difficult to turn from the outside yes. It has a huge gearing reduction. But valve cpuld be stuck also if you haven't disconnected the cables to test each side ofr which is "stuck"

I dont like pneumatics on road bikes and I will just simply expain why.
They react much more to engine load than to engine rpm. Meaning you can be 12000 going in to corner, you close the throttle-> valve closes. You give it 50% of throttle and its still closed and you're rpm is down to 11000 for example at that point and you are just maintaining speed. You open it a little more and in one point the valve opens and creates a huge spike in power. You fall off the bike if your lucky in a low side :)
 

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Discussion Starter · #5 ·
yes, it is somewhat the experience I've had, although in motocross and i haven't found it to be much of a problem in that case. but it is what was in the back of my head as to how it behaves in this particular engine, and with road use.

so far, with the valve fully opened, its quite aggressive, reminds me of old 2 stroke bikes, but still not unrideable, i would say the biggest hit is at low RPM, mids dont suffer so much. valve turns freely, doesnt seem to be stuck, so i think its just the servo that went bad, i still need to open it, if i cannot find a used controller, i still consider the pneumatic valve, but considering the trouble it is to import in my country, i might end up just doing a controller myself
 

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If you are mechanically inclined you can adopt the rotax rave 2 pneumatic valve. Very common on karting where all electronics are prohibited.
Any of the pneumatic ones can also be easily adopted. All work exactly the same with only the adjustment mechanism being different.
 

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Import to Argentina is stupid expensive. It would cost him 5-600€(if not more).. that is a big chunk of the bike price alone.
 

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Discussion Starter · #9 ·
yes, importing would be terrible expensive, and a high risk of it getting stuck on customs with low chances of retrieving it.

i have to take a look at that rave 2 system, might be an option to consider.
 

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sorry for late reply. On a normal bike (mostly stock) I would say it comes to very similar if adjusted properly.. If you're not driving in extreme conditions as I described in the first comment, I would not anticipate any problem.

But again on budget, you could get a clutch handle that has a "choke" lever on it and operate the valve manually. I almost never drive mixed low an high rpm. I either keep it low rpm or keep it high rpm. meaning I could either have it opened or closed and just flick a switch on the handlebar. like pictured. they are very common on endur bikes of 90ties era. should be easy to find. than you take one line to this, and another one on spring to opose.
 

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Discussion Starter · #13 ·
sorry for late reply. On a normal bike (mostly stock) I would say it comes to very similar if adjusted properly.. If you're not driving in extreme conditions as I described in the first comment, I would not anticipate any problem.

But again on budget, you could get a clutch handle that has a "choke" lever on it and operate the valve manually. I almost never drive mixed low an high rpm. I either keep it low rpm or keep it high rpm. meaning I could either have it opened or closed and just flick a switch on the handlebar. like pictured. they are very common on endur bikes of 90ties era. should be easy to find. than you take one line to this, and another one on spring to opose.
That is an idea that i didn't even think about, i will see if i can find something like this. for now, i managed to read the pulses that the controller receives with an oscilloscope, thinking i might just do a rudimentary valve control system with a solenoid, that would just flick the valve open and closed at lets say 8000rpm, not the best solution, but i think it would be easy and small enough with some arduino controller. i have many bikes in the pipeline still, but i hope i can get working on something like this soon, or if a better idea comes across even better.
 

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An arduino is a good solution. I don't have the energy to get "involved" with it.
But if you can do Arduino than its easy to keep the stock motor with two wires. It has a potentiometer to report position and the motor is directly driven and rotation changed by switching+ and -

You need quite a strong spring to keep the valve closed and than even stronger solenoid to open it. I made it all up using again aprilia parts, ie a solenoid of the Rave 1 controller used on aprilia RS125. But couldn't get the controller to work (an analogue one that I tried to design) as the aprilia one expected 1 signal/revolution and mito gives two/revolution (every 180°) and opened way to soon. This was 10 years ago though. O would have loved an arduino than. I had much more energy for "new" back than.
 

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Would it be completely silly to link the valve to the throttle cable? You rarely open gas completely at low rpm as the bike usually chokes. If you could make some kind of "cam" profile pulley, you could have it only start to open once you are 1/2 gas and progressively open completely when you are at 3/4 or full. It might take some trial and error, but with a 3D printer you can try several variants to get a good profile for the cam pulley.
 

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It is really easy to calculate/model the cam. But the problem is, you need either fully closed (not as much as a problem) or fully open.
But you DONT want it closed at high rpm as you will have a very very snappy throttle when it does close/open...
Its best when it is rpm dependent. Its not a coincidence that all are made like that. Even the pneumatic ones.
 
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