Having some problems with mine. I am sure it is not the engine but the newbie operator! Mine was running great till it didn't! Went dead on an upline first flight Saturday. I have about 1 gallon through it so far. All I changed from before was to richen the bottom end about 1/8th turn which seemed to help with starting. First start of the day has never been easy to start by hand. Transition and warm up were good. I'm also having issues getting an idle low enough to land the plane without chopping the ignition on final. Idles low on the ground but seems to pick up during flight. Landed the plane without incident but now I can't get it to start again hand propping it. Only got it to pop twice in about 1 hour of trying to start it. Heck with it I ordered a Megatron starter this morning. Carb is wet plugs are dry. Ignition seems iffy. I'm working on it....

I'm not having any issues at all.....after I wet the Carb, and let it sit a minute, it started right up....then today, I finally got my first flight in, on my new AW 30cc Ultimate BIPE.....this combo was made for each other....but I must say, after taxing it around for 10 min on Sat....today it started on 3rd flip today, and 2nd or 3rd flip all day afterwards....put in 6 flights today. I left the needles the same for flights 1-6....it was a super nice idle, and perfect transition, to a slightly rich full throttle. After about 3-4 flights, it started to really pull better, and richened up more....I've seen that happen when you don't change the needles, and let it break in in the air....after a gallon or so, it richens up more on it's own, because it breaking in and making more power....so next time I'll start leaning it out to a slightly rich burble for another gallon or so.....Also, I'm flying a Zoar 20x8 and Biela 20x8 (which has a huge blade) and it swings them NO problem....tempted in fact to try a 21x8....it's got tons of power, even rich on my 20x8 as is. If you're not getting significantly better performance than what you've seen on DLE30's, something's wrong.
Also, you should never just assume the carb is set....no one sets a needle and expects it too last to the end-user all set to go....you should always close the needles on a new carb, and open the recommended settings, both lo and Hi, and go from there....then you know what you've got, and how far off the rec settings your particular engine likes life.

Did all that. Really looking forward to fine tuning mine. Hard to do when I can't get it started. I will figure it out or send it back one or the other. I'm really not a total idiot. Here is my first start after 4 hours of trying. The tune was quite good as you can see. Running a 21A Vess in that video 20B for flight.

Valley View RC 40cc twin first start at dark. (4 min 17 sec)

I seem to remember a buddy having the same issue. Hand starting would not work, but using an electric starter worked fine. Turns out it was a timing issue and they adjusted the pickup sensor..I'll see if I can get the details...

SUPATIM..if you read this..which direction did Gareth's pickup need to be moved to?

Looks like a great engine for a hanger 9 1/4 scale cub.

could i have a timing issue? mine is hard to hand start. once running it runs like a top but has a slow throttle advance. but needles are set as good as it will run. i thought maybe playing with the timing

Originally Posted by Cryhavoc38

I seem to remember a buddy having the same issue. Hand starting would not work, but using an electric starter worked fine. Turns out it was a timing issue and they adjusted the pickup sensor..I'll see if I can get the details...

SUPATIM..if you read this..which direction did Gareth's pickup need to be moved to?

Thanks for checking because I really don't want to have to tote that big a## starter and battery around. Plus you always have to have someone help when you get ready to start the plane.

I would place a call over to VVRC before messing with the timing. I am sure if it is off, they can help you get it set up correctly.

As far as the starter. I have a very old sullivan starter that I have attached a 2650mah 4s battery to. I have seen people use a 3s setup as well, but the torque at that voltage is much less. It turns over my twin 40 as easily as it does on my larger 4 stroke. It is definitely easier than carting my old RC field box with the 12v battery around.

Originally Posted by Cryhavoc38

I seem to remember a buddy having the same issue. Hand starting would not work, but using an electric starter worked fine. Turns out it was a timing issue and they adjusted the pickup sensor..I'll see if I can get the details...

SUPATIM..if you read this..which direction did Gareth's pickup need to be moved to?

My problems were solved by swapping the ignition module for an older RC-XL module. My current guess is the new ignitions have a higher minimum RPM that they spark at. With the older ignition I have had Zero issues hand starting this motor. I looked in the problematic ignition to see if there is anything for us to adjust but it is entirely potted in epoxy.

Moving the pickup around did not make an appreciable difference in starting behavior.
Neither did changing out the plugs for NGKs.

Overall I really like the motor. It's got great power and pulls my 78" Extra around with authority. Throttle response is snappy. With the right ignition startup is the same as any other gas motor. And its a twin so its going to cause less vibration and my airframe will have fewer fatigue issues

I do wish it was quieter. Anyone want to make a set of mufflers for this things with some baffles in them?

Some trick 'n tips:
I had one of the spark plug wires work loose and fall off the plug. The little micro plugs don't have a secure clamping ring like the the CM6 plugs do. I secured the plug wires on mine with small loops of pull-pull cable. Looped through the holes in the cooling fins and around the plug cap. It does NOT have to be tight, just short enough to prevent a full disconnect.

I'm running a Falcom 19x8 but my idle could be a little more confident. Victor and Supa-Tim are running heavier props and their idle is better. Heavier props also make it through the first rotation with less speed loss when starting. I would consider heavier props to give this thing some more rotational mass (Mejzlik carbon or Xoar wood).

I have tried everything to keep the little motor cool. I've baffled it and cut a pile of vent exit are in my cowl. I still get temp readings over 200 on the back cylinder. My DA-100 comes down at like 180. I don't have that many gallons through it yet though so maybe this will improve with break-in.

Originally Posted by gareth.ky

My problems were solved by swapping the ignition module for an older RC-XL module. My current guess is the new ignitions have a higher minimum RPM that they spark at. With the older ignition I have had Zero issues hand starting this motor. I looked in the problematic ignition to see if there is anything for us to adjust but it is entirely potted in epoxy.

I could be totally wrong, but I think this may be the issue I am experiencing. I think the "newer" style ignitions are not seeing enough RPMs for my motor to start at first. I think that after break-in it is a little easier to prop it faster as mine is still pretty tight new. Mine starts instantly with a starter - every time. I also think that is why ppl are getting them easier to start with a larger prop... more momentum going around to fire the plugs. I think my needles are perfect.

Where is a good source to buy the older ignitions? I might try that instead of buying a starter. I was looking at a Sullivan Dynatron with this Makita LTX adapter, but all-in is about $150 - $200 depending on what (if anything) you do have.

Originally Posted by gareth.ky

My problems were solved by swapping the ignition module for an older RC-XL module. My current guess is the new ignitions have a higher minimum RPM that they spark at. With the older ignition I have had Zero issues hand starting this motor. I looked in the problematic ignition to see if there is anything for us to adjust but it is entirely potted in epoxy.

Moving the pickup around did not make an appreciable difference in starting behavior.
Neither did changing out the plugs for NGKs.

Overall I really like the motor. It's got great power and pulls my 78" Extra around with authority. Throttle response is snappy. With the right ignition startup is the same as any other gas motor. And its a twin so its going to cause less vibration and my airframe will have fewer fatigue issues

I do wish it was quieter. Anyone want to make a set of mufflers for this things with some baffles in them?

Some trick 'n tips:
I had one of the spark plug wires work loose and fall off the plug. The little micro plugs don't have a secure clamping ring like the the CM6 plugs do. I secured the plug wires on mine with small loops of pull-pull cable. Looped through the holes in the cooling fins and around the plug cap. It does NOT have to be tight, just short enough to prevent a full disconnect.

I'm running a Falcom 19x8 but my idle could be a little more confident. Victor and Supa-Tim are running heavier props and their idle is better. Heavier props also make it through the first rotation with less speed loss when starting. I would consider heavier props to give this thing some more rotational mass (Mejzlik carbon or Xoar wood).

I have tried everything to keep the little motor cool. I've baffled it and cut a pile of vent exit are in my cowl. I still get temp readings over 200 on the back cylinder. My DA-100 comes down at like 180. I don't have that many gallons through it yet though so maybe this will improve with break-in.

ah thats what It was. I misremembered with your situation. thanks G

I have heard about customers having a problem starting the VVRC 40cc twin and I do not know the answer, putting gas in the carb with the airplane inverted sounds like it may help? I run each engine before we ship it but I use an electric starter. I run many engines each day and if I tried to hand flip them at my age my arm would fall off! I have worked for almost a year getting this engine the way I wanted it and we will keep reading this forum and try to make improvements in the engine.

They are selling almost as fast as we can get them assembled and test ran but we do have a few in stock so if you need one now is a good time.
Thanks for using our engine and watch for the next generation VVRC 20cc engine.

Tom, Thank your comments and for monitoring the (minor) issues with the engine on this forum. I am extremely pleased with how my engine has performed. I know others are as well.

Tom suggested the trying the ignition swap as an experiment and I sent him a report on my (admittedly limited) testing about a month ago.

I proposed building some kind of test jig to validate the minimum sparking RPM of the ignition. If people really really want to know I will see if I can make something in my garage.

Is there some easy way to determine if there is voltage going to the plugs when hand starting the engine? What I do not understand is that I have little trouble getting the engine to pop when the choke is on. I wonder if with a tight cylinder as well as being a twin, we just are not getting enough speed or momentum to carry it into the second compression cycle.