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Nirvana Rodeo Starting problems


adamjedgar

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Hi guys,

 

Background to my issue

i have a nirvana rodeo with a simonini mini 2 plus engine (200cc).

It has about 100 hours on it now, and i have done virtually nothing to the motor since new (it has been very reliable). I did pull the head off once because i thought that perhaps the decompression port was blocked (i almost exclusively use the electric starter because it develops so much compression i can barely start it with the pull starter).

 

anyway a couple of flights ago i noticed that i could not get the engine to fire when cold starting using the electric starter. I then went for the option b (the dreaded pull starter)...and since i am barely able to pull this beast using that method i was pleasantly surprised to hear a crackle and into life came the engine from barely enough revolutions per minute to consider it a decent pull.

I warmed up the engine, shut it down..got out my gear and wing, put the unit on my back and she fired up with electric starter at this point no problem.

 

Next time i went to fly the motor, which was that afternoon, same thing again...engine would not fire using electric starter when cold, i gave it a pull and away she went...shut down to setup wing and put gear on...put paramotor on my back, hit the electric starter...she fired up straight away.

 

Third time (the following day) same as above again...no fire on electric when cold, but fired up using pull starter...shut down to setup wing, put motor on back, fired up using electric starter no problem.

 

Fourth time, no fire electric...i accidentally broke the pull starter...no flying whilst i wait for a new part for the pull starter.

 

the nirvana rodeo is a 16.8 volt system

it has two switches, one for the starter and a second one for the ignition

I have cycled and recharged the nicad battery pack

I have pulled the spark plug out and checked it for spark...its not exactly the sort of spark i remember 2 stroke lawn mowers used to produce when i repaired them 20 years ago...so to me the spark seems weak. I changed the plug for another second hand one i had laying around from a different engine, it produced an identically weak looking spark and also motor will not go using electric starter (i cant use pull starter now cause i broke it and am still waiting for replacement parts to arrive)

 

I have reset all mixtures back to the Nirvana factory defaults for this engine, 3/4 low speed and 4/4 high speed (thats 1 full turn high speed)

I plan on buying a brand new spark plug as it may be possible that the old second hand plug i pulled out of an unused engine is also cactus 

 

Now to my question...

 

Can someone help me problem solve why the simonini mini 2 plus has suddenly decided to only pull start when cold but quite happily electric starts when warm? (cranking speed seems fine but it will not even so much as fire with electric starter when cold)

 

I will avoid putting my gut feelings out there right now as i would really like a completely fresh input into problem solving this. 

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13 hours ago, AndyB said:

Your battery is likely knackered. Can you measure voltage at same time as you use the starter. It will probably dip really low....which will be too low for a good spark. 

Hi Andy,

I have had that one mentioned to me before. however, shouldnt this engine be able to run without a battery? If so, than the ignition system produces its own electrical current from the motor not necessarily the battery in order to produce spark.

 Or, would it be that if the battery is nackered, then the starting system is drawing too much power from the charging system whilst cranking on the electric starter...therefore not leaving enough to produce a decent spark? Can this actually happen?

This was one of my gut feeling theories mentioned but not described in first post. I intend to test this theory by separating the two systems and trying again (ie connect the starter motor directly to an external power source completely independant of the paramotor to see if it fires.

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The second one. That is why I suggested measure voltage while cranking starter. If the ignition is on the same "live" wire then it will produce a weak spark.

NiCd are prone to degradation and 2 years would be old. You will likely find that a 4 cell LiPo (14.8 volt nominal, but 16.8 when charged) will give you an amazing starting power.....as a LiPo will give much higher continuous current than NiCd.

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5 minutes ago, AndyB said:

The second one. That is why I suggested measure voltage while cranking starter. If the ignition is on the same "live" wire then it will produce a weak spark.

NiCd are prone to degradation and 2 years would be old. You will likely find that a 4 cell LiPo (14.8 volt nominal, but 16.8 when charged) will give you an amazing starting power.....as a LiPo will give much higher continuous current than NiCd.

I was interested in the Lipo option however i was deterred from going down that pathway because the nirvana system is setup for charging nicads and has no controller on it for lipo's. I have tried to contact nirvana about this to determine exactly how the charging system on the nirvana works...is it a pulse charging system (as is required for nicads and Nimh batteries)?

 

My understanding is that pulse charging is not suited to lipos?

I have a motorcycle 12 volt lipo in my other paramotor...its brilliant. Not only is it a lot lighter than the nirvana battery pack, as you say, it give phenominal cranking power and will go on cranking for a long time before going flat.

 

I have considered perhaps changing the nirvana system back to 12 volt...why its 16.8 i dont know? 

Edited by adamjedgar
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Correct, LiPos must use a balance charger designed for them - a balance charger essentially charges each of the individual cells separately so that they are not charged outside of their voltage range, which cause fires!

The LiPo option is still OK, but you would need to ensure that it was NOT being charged when on the machine. A LiPo is so much lighter than NiCd you will find a decent size LiPo will likely give you dozens of motor starts without having to re-charge it.  Then the battery should be removed for charging and placed inside a fire-proof bag (LiPo charging bags are standard kit now).

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14 minutes ago, AndyB said:

Correct, LiPos must use a balance charger designed for them - a balance charger essentially charges each of the individual cells separately so that they are not charged outside of their voltage range, which cause fires!

The LiPo option is still OK, but you would need to ensure that it was NOT being charged when on the machine. A LiPo is so much lighter than NiCd you will find a decent size LiPo will likely give you dozens of motor starts without having to re-charge it.  Then the battery should be removed for charging and placed inside a fire-proof bag (LiPo charging bags are standard kit now).

ah ok. If only it was a 12 volt system...the lithium motorcycle battery that i have has its own circuit board built in to it...i am assuming this controls voltage to the battery. For example, i have 2 of these motorcycle batteries...one of them had its voltage drop to around 9.8 volts. I cannot charge it as the circuit board wont allow any charge to the battery. 

 

I am assuming this would be the kind of battery i would need...but not in 12 volt obviously. Unfortunately the manufacturer doesnt make them in suitable voltages for my paramotor

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here is a photo of the battery i use in my other paramotor. Well actually, this is the one that i accidently let voltage run down too low on and now wont charge anymore (it wasnt in my paramotor at when this happened...i was using it for something else and it went flat and then got left sitting around for a long time).

Having said that, this is the type that can be recharged in the paramotor whilst running.

lithium Motorcycle Battery 2.jpg

Edited by adamjedgar
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i have taken two short videos of the paramotor engine turning over. 

Video 1 is showing the spark (which i now realise is quite good now that i have checked it when not in direct sunlight).

 

Having said that i notice that when i begin to turn engine over, it takes about 1.5 seconds before any spark is generated. Is that normal?

 

Video 2 is of motor being turned over with plug in using its own battery. Surely this is suggestive that the battery pack if fine?

 

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Do you think its safe for an air cooled 2 stroke to ingest aerostart? Wouldnt it stand a good chance of burning/blowing a hole in the piston? Its pretty high octane stuff. When you do it, do you spray then wind engine over or wind it over then add spray whilst its winding over? (How do i control engine rpm with this stuff...if it fires and races im in trouble?

i was thinking perhaps i will just try some fuel straight down plug hole first to see if it will fire.

 

EDIT....

I also noticed yesterday that the primer doesnt seem to be mantaining pressure for very long. (ie its going quite spongy like no fuel is still init after a short period of time...perhaps 5 minutes)  Im sure this wasnt the case before

Edited by adamjedgar
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Adam,

I had Nirvana Rodeo for two years, the primer should never looks spongy.

Silly question, but does the walve in the fuel cup work? If you take of the cup before the flight is the air going inside (that should not happen).

Can you check the filter? Do not remember, is it in the tank or not now. 

Have you tried adjusting the carb? I do not believe it is a baterry problem. Carb needs adjusting if the temperature shif is more than 15 degrees and in some other cases. 100h might be one of them. Do you have the RPM meter installed? Had max RPM fallen since the problem occured?

Have you contacted Nivana technical support (head office) ? They should be quite experienced in this sort of problem. I usually called them instead of writing an emails - they did not tend to answer promptly at all the occasions. 

I tried not to use manual starter on Rodeo - in my oppinion it is not designed for every day use.... just as an emegrency option.

PS I would not use easy start to be honest. The best option is to find the problem then to deal with consucecuences...

PPS looking at the video it seems that it is a problem of lack of fuel then something else, and the spongy primer only makes this more likely.

The fact that it is spongy means that that it is not enough pressure in the pipeline. Check the filter first thing.

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Adam,

I fly the the Rodeo too.  Take a look at my YouTube video here:  https://youtu.be/IY_muQ8XUEE - shows a possible solution!

I've had what sounds to be exactly the same issue.  I thought it a battery issue - mainly because I flew with plenty of other Rodeo flyers and their props rotated much faster when starting than mine.  So I charged the battery and no change - I used their battery and no change!  So the issue had to be the starter.

I agree that the Rodeo is a pig to pull start!  Clearly not optimise for pull starts - but then it's only needed in an emergency.

I spoke with Ryan Shaw (US Nirvana importer - I was in the US in Florida then) and advised it might be the starter.  He recommended the better quality starter fitted to the Instinct - I bought that and the problem went and has not reappeared.  I am on the same battery from new and that is now 3 years plus old.

It looks to me like the starter motor is your problem - I see you are in Australia so if parts are an issue then maybe you can source the starter elsewhere?  The one I have now is apparently Japanese made.

Regards

Tony Wheeler

 

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hi guys, problem sorted.

Even though the NGK spark plug was producing spark when testing, i purchased a new plug at my next opportunity (actually got 2 of them NGK BR9ES and NGK BR10ES). When i connected the plug up i initially thought, oh crap now it has got no spark (i couldnt see a thing)...however i figured that perhaps its just very difficult to see a very light coloured spark on the background of a brand new plug and inserted the BR9ES plug into the unit and hit the starter (its winter time here so i went for the slightly hotter plug as my old plug is tending to run the engine a little black which perhaps may be why i only got 100 hours out of the old plug?)

 

I run 50:1 synthetic (Motul)

My carby settings are usually pretty much factory on the low and a leaner than factory on the high speed as the engine misfires at lower rpm settings in the air when i leave high speed at factory settings. I suspect this is because i fly in a relatively warm climate and at sea level + 2000ft most of the time?

 

Because i am only flying the 25 mtr Dudek Universal wing, i dont really use high power settings at cruise very much at all...mostly 1/3 throttle with trimmers closed and perhaps  1/2 throttle trimmers open. Because prior to this point i havent regularly undertaken long distance xc work...i dont fly with trimmers right out for very long or very much...I am mainly down very low scooting around with trimmers shut as i dont feel its particularly safe to fly low to ground with trimmers out more than about 1/3 at this point in my motoring experience.  I have 100 hours motoring, on the Universal, and also have an additional 400 hours free flying of which the last 100 hours is flying an Icepeak 6 - 2 liner competition wing..

 

Anyway, after installing the new plug into the Rodeo, she "cold" fired up instantly without even so much as a peep of priming. 

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17 hours ago, adamjedgar said:

hi guys, problem sorted.

Even though the NGK spark plug was producing spark when testing, i purchased a new plug at my next opportunity (actually got 2 of them NGK BR9ES and NGK BR10ES). When i connected the plug up i initially thought, oh crap now it has got no spark (i couldnt see a thing)...however i figured that perhaps its just very difficult to see a very light coloured spark on the background of a brand new plug and inserted the BR9ES plug into the unit and hit the starter (its winter time here so i went for the slightly hotter plug as my old plug is tending to run the engine a little black which perhaps may be why i only got 100 hours out of the old plug?)

 

I run 50:1 synthetic (Motul)

My carby settings are usually pretty much factory on the low and a leaner than factory on the high speed as the engine misfires at lower rpm settings in the air when i leave high speed at factory settings. I suspect this is because i fly in a relatively warm climate and at sea level + 2000ft most of the time?

 

Because i am only flying the 25 mtr Dudek Universal wing, i dont really use high power settings at cruise very much at all...mostly 1/3 throttle with trimmers closed and perhaps  1/2 throttle trimmers open. Because prior to this point i havent regularly undertaken long distance xc work...i dont fly with trimmers right out for very long or very much...I am mainly down very low scooting around with trimmers shut as i dont feel its particularly safe to fly low to ground with trimmers out more than about 1/3 at this point in my motoring experience.  I have 100 hours motoring, on the Universal, and also have an additional 400 hours free flying of which the last 100 hours is flying an Icepeak 6 - 2 liner competition wing..

 

Anyway, after installing the new plug into the Rodeo, she "cold" fired up instantly without even so much as a peep of priming. 

Adam,

Great to hear it's ok now - but do beware of using the wrong plug.  Did you look at the YouTube video link?  It seemed to me that your prop rotation speed was slower than it should be regardless of the plug issue.  In my video you'll see the difference changing the starter motor made - huge increase in rotation speed on the same battery with no charge.

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yes the right plug is important, however, i think that as my old plug is running black at factory settings and i have been advised not to lean mixture my only other option is the go to a slightly warmer plug at this time of the year.

that starter of yours certainly cranks the motor over much faster. A question, what voltage is the new starter motor you purchased?

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  • 2 weeks later...
On 05/08/2017 at 00:29, adamjedgar said:

I have been wondering why Nirvana choose to use a 16.8 volt system?

Anyone ever looked into changing it over to 12v so it uses similar parts to motorcycles? I am not an autoelectrician, and although i have a bit of an idea, what would be involved in doing that?

You can actually use many parts with that voltage as it's often in the range of allowable voltages for the input.  I added a USB double socket for charging devices - that was a motorcycle part (wired to the battery connectors).

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11 hours ago, tonyjwheeler said:

I am selling my Rodeo.  Working perfectly and in great condition - just changed to a light paramotor (AC Nitro 200) - Interested?  See here: https://www.paramotorclub.org/topic/11160-nirvana-rodeo-for-sale-£3200-ono/

What is the weight difference...i used to think i could go to a lighter unit but now i wonder if the problem is the engine weight rather than the nirvana equipment. 

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  • 3 weeks later...
2 hours ago, tonyjwheeler said:

Adam, 10 Kgs!  That is really quite noticeable.

eh??? That means that without fuel, your new unit weighs 18kg...oh my goodness thats so light its almost unbelievable. I went to the airconception website and was amazed at the engine weight...just over 11kg. Thats really really impressive, I am sold on that engine.

I need to look into the Nitro as the only comparison for weight that comes close is my DLE 200 engine is its very light weight 12kg. The trouble with this engine is that is also very noisy and hasnt got as much torque as i would like due to the short stroke (its a model aircraft engine). On a paramotor i love the lightness but its way down on thrust compared to SImonini mini 2 plus. This Nitro engine on the other hand, looks fabulous :coptor:

Edited by adamjedgar
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