glofuel

I have a new mvvs 58 pro which will not run.....[]

spent 2 1/2 hrs flicking my arm off, she will fire up easily every time once primed but wont keep running - prop turns a few times, then will often start bouncing back and forth and then stop but will not rev up

plenty of fuel supply, checked mixture needle settings tried factory settings and settings advised by just engines which were different and also tried leaning/richening either way until she wont fire at all (too rich or too lean)

dismantled carb for any signs of problem but nothing found.

have noticed that it kicks back very easily (it hurts) sometimes loosening the prop, I thought the timing was retarded on start up ?

Dismantled carb/reed valve assembly and found the two carbon reeds do not shut properly- is this normal for a new engine ?

I am beginning to think there is a timing problem with the ECU or maybe the prop driver with magnet has been fitted out of time with the sensor

Choke is set up with servo for auto from Ign unit (seems to work well) although have tried with it disconnected
fuel is 30:1 using oil supplied
battery is 1500mA 3 cell lipo 11.1V
tank is approx 4!QUOT! from carb

I have many years experience with glow and petrol but this one has stumped me [&o]

Any help from you guys would be appreciated, unfortunately support from Just engines where I bought it from is not available at the moment due to there bereavement

rmenke

My Feedback: (13)

glowfuel:
From the kickback problems, suspect you are advanced too far on the igntion side. Retard it a little and see what goes. Your engine is the same as the Evolution, so you may be able to get some assistance from Horizon Hobbies. Have seen a number of carbs that need main jett needle adjustment springs changes recently. If you have a pressure guage for checking such, do it. Hope our guys in Israel are ok. ENJOY

glofuel

rmenke:

Thanks for the reply,
I understand what your are saying, it does look as if it is firing to early, but there is know way of adjusting the sensor/magnet position (it's not designed to be adjusted mechanically) and as far as I know it is not possible via programming the ECU either.

Unless you need one of the programmers which is not available at the moment for my PRO version. all you can do at the moment is set long or short silencer pre-ign curve. what that actually does I have no clue because the instruction sheet is pretty vague.

As for the needle lever height I can't see that being the problem as there is always fuel there getting sucked in, no I don't have a pressure gauge and really don't have the time for that sort of testing.B

But after more trying to start it I have almost come to the conclusion that there is a fault with the ECU.

except I have since inspected the reed valve assembly and there is a open gap of approx 10 thou on both carbon reeds. another words they are both not closing at all. The types I have seen in the past have always been closed pretty firm.

Jenny at Just engines has e-mailed mmvs but I don't what to keep pestering her at the moment for obvious reasons.

Any further comments would be much appreciated

cyprusjets

glofuel
Please check on the flywheel if your magnets are 120 degrees,if its 180 degrees it will not run because of the bad timing with the icu-p. I had a similar situation here in Cyprus last week where i found that i had 2 prosports with the same problem by mistake of the factory now the problem is solved after i modified the flywheel to satisfy the customer and the new 120 degree flywheels are on the way so if this is your problem contact to the shop where you bought it i am sure they will fix the problem.

Regards
Eftychios

glofuel

Eftychios

My fellow modeler who is a car mechanic did say it looked as if it was firing 180 deg out and I agreed, But I checked the position of the magnet/sensor/piston position and it appears to be firing TDC on the first magnet.

but as for the 120/240 deg magnet position on the flywheel (has 2 magnet version) I am not sure how this is actually measured in relation to the engine/piston stroke - can you en-lighten me.

I am guessing it is 120 and 240 deg looking from the front with the cylinder upright with piston at TDC

Also is the flywheel/prop driver fitted onto splines or is it keyed with a woodruff/half moon key on the shaft, another words can it be removed or pulled off fairly easily

thanks
Ian

cyprusjets

as you can see the magnet on the pictures i have upload what i am asking you is, if the 2 magnets are opposite site then is 180 degrees , if you have a flywheel like this where the one magnet is at the one site and the other one totally at the opposite with the new icu-p the engine would not run at all. If the one magnet is only 120degrees from the second one then it should run fine. when is 120 degrees the one magnet is 2 places after the other and not totally from the other site of the flywheel, check this and let me know which kind of flywheel you have.

Regards
Eftychios

glofuel

Eftychios

I understand what you are saying now,

I believe my one has the 2 magnets completly opposite each other as you say 180 deg which as you also say will not run, but I will go and have a look to confirm this.

If this is the case I maybe able to do as you did and modify my one for time being untill I can get the proper one later

thanks for responding so fast with pictures

regards

Ian

cyprusjets

Ian
Before you modify anything you need to be sure which magnet to move of the 2 and in which position to put it otherwise if you put it in the wrong position it will not work properly because the timing of the engine must be precised, after you check your prop driver if you are going to modify it let me know so i can give you step by step the way you are going to do it, is not that easy and you need to go with the right procedure so let me know.

Regards
Eftychios

glofuel

Eftychios

yes I know what you mean, I am just going to workshop now will reply with confirmation of magnet position in a few miniutes

ian

glofuel

Eftychios

Yes I have the 180 version and I see that the second magnet needs to be on the second position after the first (each position = 60 deg), I presume the magnet that is nearest to the pro sport markings stays where it is because this one makes plug spark other one does not.

are both magnets polarised the same way ie north or south poles pointing nearest sensor or are they opposite and how did you remove the wrong magnet ?

ian

cyprusjets

Ian
Thats correct, the magnets are polarized the same way, i removed the magnet by heating the aluminium to high temp for some time till the magnet flip out by it self, you have to polarize again the magnets after the heat , and the hole you are going to make have to be 5mm, find the center of it make a mark there with something sharp and then start with a 2mm hole then 3,5-4 mm and then make the finish to 5mm. Btw if you make any modifications mvvs will not change your propdriver afterwords, and they will charge for the new one, but if you tell them about this problem before you modify it you will just return it and they will change it for free, its up to you.

Brg
Eftychios

glofuel

Eftychios

Thanks for your information

I am glad I know what the problem is now

I will contact Just Engines where I purchased it from first and let them know of this. I know they had a new delivery recently from mvvs and I am sure they will have more customers with this same problem.

I am hoping they have correct version in stock, if not it may take a while before I recieve it myself so I will modify this one for now

Do you have any more info on this newer ECU-pro such as how do you access and modify ign curves it says on the simple instructions I recieved there are 4 curves and what difference is there between setting short/long ign curve (I have 3204 canister) ?

regards
Ian

cyprusjets

Ian
As i ve seen is just 2 settings with the ignition the one is for canister and the other one is for Pitts muffler. With your ignition is coming an extra wire where you have to set your remote on which exhaust you will use. Thats the only setting you can access and is just for the optimum and best performance, good luck with the propdriver and if you decide to modify your one just be careful with it and trust me after you ignite that engine you will love it. Let me know your results and your impressions for this engine.

Brg
Eftychios

glofuel

Eftychios

I know, I also have a Evolution/mvvs 26cc petrol and that is superb with a tuned pipe on my H9 funtana and so cheap to run, no more glofuel cost's !!!!

thanks again

Ian

BaldEagel

glofuel

Have Just Engines replied to you yet, I also have an MVVS 58Pro with the magnets at 180 deg, I don't want to keep bothering them at this time for obvious reasons.

Mike

glofuel

Mike,

No not yet, but I am sure they will in good time

Ian

BaldEagel

glowfuel

Recived an e-mail from Jenny they are working on it?

MIke

BaldEagel

Just to throw another variable into the pot, is not the second magnet only there to inform the ECU of the revs? if that is so should not the engine start but just run rough due to having the wrong advance, because it is being informed of slower revs than actual? Now there's a thought.

Mike

glofuel

Mike:

I don't think so, on mine after spending a few hours trying to start her, she just fires up, runs forward a couple of turns then starts bouncing back and fourth for a second or 2 and stops regardless.

which must be due to the fact they have the 180 deg magnet positions (for earlier ign unit) instead 120 deg for the new MSR type which we have

Ian

Extra_300_S

Hi guys,

I need to remove the drive washer (flywheel) on mine and I can't. What's the trick?

Thanks.

BaldEagel

glofuel

Yes I know in therory the 180 : 120 is wrong, but why is there a magnet at 180 or 120 if not to tell the ingnition unit what revs the engine is doing, with one magnet at TDC that is all the ingnition needs to know to set the advance or retard on the spark, but it will need to know the revs to set the curve, so I come back to my original thought that the second magnet is just to let the ingnition know what revs the engine is doing.

This is all suposition on my part as there is no technical information available for this ignition system, if anyone has any information on this please let us know.

Extra-300-S

Do you mean the prop drive hub?

Mike

Extra_300_S

Baldeagel,

Yes, the prop drive hub the magnets are attached to and timed with the woodruff key.

BaldEagel

The front shaft is threaded into the crank and has a flange on the front of it to hold the prop drive hub in place, I should think this is Locktite in place and will be difficult to remove.

Why do you wish to remove it anyway.

Mike

BaldEagel

I am sure you know but please do not jam something into the exhast port against the piston to stop the engine from turning against the applied tourque to the front shaft, not only will this damage the piston but there is a real chance of bending the con rod.

Mike

Extra_300_S

Mike,

The threaded front shaft has been removed in a safe manner but I can't pull out the hub.

JF