radfordc

My Feedback: (14)

I purchased a VVRC 20 with J-Tec wrap around muffler for my TF P-51. Five flights so far and it is working great. I am using a Turnigy 17x6 wood prop. You can get an idea of how well it pulls the plane here:

http://www.rcuniverse.com/forum/rc-w...l#post11821880

radfordc

My Feedback: (14)

On the test bench It turns a Zinger 16x6-10 at 7000 rpm and idles reliably under 2000. I didn't have to touch the needles out of the box.

http://www.rcuniverse.com/forum/rc-warbirds-warplanes-200/7520206-top-flite-60-size-p-51d-mustang-arf-building-modifications-107.html#post11817470

<iframe width="560" height="315" src="//www.youtube.com/embed/3o-yM2r8xpE" frameborder="0" allowfullscreen></iframe>

racer4ever

Can someone please PM me. I cannot figure out how to create a thread/question on this website.

lean-run

Have one of these on order.

Like the 20c.c. size of model for transport and storage, and the engines are not lacking on power.

Still can't get over the vertical climb, can't wait to add a VV20 to the stable.

Ernie Misner

You have to register/log in first. Then at the top of the forum it will say "Start a New Thread" or similar. Just click on that.

Ernie Misner

General consensus around the gas engine forum seems to still think: " Stay with 32:1 with the 20cc engines."

Lifer

My Feedback: (1)

The instructions call for 32-1 as well.

j301

My Feedback: (12)

Just finished up a TF P51 and put this motor in it. It ran great on the test stand, but now in the plane it will only run for about a minute then die. You can restart it, but it will cut out again. When/if you are able to get the rpms up, it will die then restart itself, repeat that a few times then just die. At that point I have to re-choke to prime, then it will just repeat the cycle. I tried many needle setting combo's, both low and high, to no avail.

I pulled the motor, back on the test stand and re-tuned. Figured it was a fuel problem so I re-plumed and re-installed. No change. I tried feeding with an external tank from the test stand, same outcome. I put the ignition from another motor on it, no change. So basically the only thing the motor has in common with the plane is that its mounted to it, everything else is external.
I pulled the carb, cleaned the screen, no change.
Any ideas?
Tomorrow I will pull the motor and ignition and bench run it again to see what it does, but at this point I feel I have tried everything but swapping the carb out.

Ernie Misner

Can you see when the fuel stops drawing through the tubing? Sounds like it is not pumping properly alright. I'd sure try another carb if you have one. Don't hesitate to call VV and talk to them also. Have you reversed the carb position or anything? The hole for pump pressure needs to be clear. What is puzzling is that it pumps at first and will run though.

j301

My Feedback: (12)

I put the motor back on the stand and pulled the ignition from the plane and it got it back in tune again. I let it run for a while and it seems to be holding. When I re-mount it and run it again I am going to start by not mounting the ignition in the plane and use the external tank, battery, and switch to see how it goes. If it runs, I will swap one component at a time over to the plane's and run it with every change to see if I can isolate the culprit. (If it doesn't run the first time by just having it installed I guess I will have to assume it some how has developed a conscious and knows that its life expectancy is reduced by 75% by being in a plane!)
Keep your fingers crossed and I will let you know how it goes!

Gizmo-RCU

My Feedback: (27)

Flew today, the engine ran well until the temp got up to 95 degrees and then it started showing the heat, it was missing a little and leaning out. I stopped as it would have required a little tuning and it was so hot it wasn't fun anyway as the tarmac was really hot..............
This little engine is really coming on @ about 2.5 gallons thru it.

j301

My Feedback: (12)

Mounted mine back on the plane, no cowl, EVERYTHING just as it was on the stand (only the servo to the throttle now added and with the exception of perhaps the 12" elevation difference between my stand and my cradle). Even the mounts one the stand and the plane are the same-both Great Planes large motor mounts, and still nothing. It absolutely refuses to run when its mounted to the nose of the P51. I don't know what else to try. How does one send back perfectly running motor that just wont run? I know its not the hole in the carb for the pump, its lined up, and its not a "pressure in the cowl problem" as I always fill in the original hole on the carb plate and run line from a center tapped, 90 degree nipple to the fuse (I use a pill bottle instead of a 35mm film canister) as I have had that problem in the past. Could it be a tuning issue? But how drastic of a change could it be? I wouldn't think enough to go from running to not running, plus I've tried a lot of tuning already. Felling like I might just be hosed with this one.

Lifer

My Feedback: (1)

Please take no offense, but are the fuel/vent lines correct?

j301

My Feedback: (12)

No offense taken from any body trying to help! I didn't even make it that far as I used the single line from my test stand "tank" (which is basically a fancy water bottle with two holes in the top, a clunk, and filter). It the same tank/elevation/plumbing as it was on the stand as I wanted to duplicate its running condition. The only thing I can think to try is one of these so it will get its air from inside the fuse:

Gizmo-RCU

My Feedback: (27)

Well I ran into a glitch. The engine started missing when under load and Dead-sticked on me several times (no Problem). It would restart after cooling and run fairly well for a while. The engine was not unduly hot and turned over smoothly
it drew fuel as always and the plug was wet after trying to start it with an elec. starter, seems to be no problem with fuel? (32 to 1, 92 oct. non ethanol w/ Stil Ultra oil). I then spun the engine with the starter grounding the removed plug and had
a very weak almost invisable spark. My ign. Battery was at 6.25 volts at the time. 2500 NmHi's .
Almost certain the ignition has failed?

I will call VV this am and see what they desire.......love the engine, about two gals. thru it now and really good power for my 120 Ultra Stik

j301

My Feedback: (12)

After trying a myriad of things, I finally got mine to work. I had to re-route everything away from the hole in the firewall (usu. meant for the stopper of the tank-tank is moved back in my case) as it passed directly in front of the carb intake. I also re-routed the pick up lead to outside of the motor mount. I originally had it passing between the mount and the carb, could have been causing a choke on the pulse I guess. I cant say what finally fixed it, but it had nothing to do with the battery, tank, ignition, radio, or anything else on board the plane other then the way I had it running in the engine compartment.

GIzmo, I agree, it sounds like an ignition problem, with the box or maybe even the plug. ( I also had an issue with my Rcexl opto once I hooked it back in to the system. It was randomly killing the motor, had to replace it with another unit). If you have a physical (snap or toggle) switch for the ignition, did you try checking the spark with it bypassed? Sometimes switches can cause issues when they have, or are just about to, fail.

Gizmo-RCU

My Feedback: (27)

Talked to VV this am, they agreed that it sounded like an ignition and are sending me a new one, I tried the ignition with the plug out this morning and got a good snap but I got that Saturday until the engine was ran in flight for about 7-9 mins. before the problem came up as a miss and deadstick. Pulled the plug then and had a feeble spark, the engine would start but not sustain a running condition. The temp. was over 90 but I don't think that caused the problem

Will change out when the new one arrives.........Good folks at VV and yes I am quite happy with their support!

j301

My Feedback: (12)

Mine started acting up yesterday, long story, but I thought I had it under control (famous last words no?) Haven't touched anything since the maiden flight, but it only wanted to run with the choke. Did some fine tuning, all seemed good. Did a few taxi tests, even high speed, wasn't missing a beat. Lined up, took off, got about 15' and it went very bad-way down on power, sounded like it was 4 cycling. Cant really ditch and survive here in the desert, so I limped it back to the runway only to have it snap and go in hard at the end of the runway. Total loss of the Top Flite P51, the motor seems ok, but I cant trust it so I am considering it a loss too. Now I have to decide if I want to contact VVRC. I should have just pulled it from the start and sent it back, but this wasn't my first gas motor, and I'v gotten some really stubborn ones (TGY 52 for example) to run reliably, so I thought one of this reputation would work out.

Ernie Misner

I'm sorry for your loss which is always frustrating. Hind sight is always 20-20 and not running unless the choke was on was probably the give away of some sort. Could have been an intermittent piece of crud in the carb or something. Seems like you have nothing to loose by sending the engine in to VV and at some good info to gain. Maybe someone else will benefit from that too.

gophcg

My Feedback: (7)

Awesome engine. Mounted on Hangar 9 P47 60. 16x8 prop 32:1 oil. Set the needles last fall and have not touched it since. Highly recommended.

Gizmo-RCU

My Feedback: (27)

The ignition came last week and is installed. Good spark when tested.
Due to other obligations I could not get to the field until yesterday. Hot and very windy (gusts) so opted not to fly as it would not be much fun anyway........will up-date soon.

j301

My Feedback: (12)

Contacted them last week, no word back from them yet. Little surprised as they "have such great service." I'll have to call them I guess.

Pete1burn

Let us know how it turns out.

bcchi

Does not sound like fault of the engine.Maybe operater error.Have both the VV 20&40 and both are great.They as most engines need some time on them .Sorry about your loss. Tom probably does not no what to say.
BCCHI

j301

My Feedback: (12)

Trying not to take offence to that as the operator, but I can say I did not hit the "run like $#*^ and crash my plane" switch on my radio by accident. And I did become very familiar with the motor after a week of on and off the stand, tweak and re-tweak, clear the carburetor, etc. (and I have several two stroke motors at the moment that all run well). I'll leave it at that and come back to this later as everything I type seems to read much more like a rant then I intend it to.
Though I will say I might try a WT 540 carburetor on it, that's the carburetor that I have on most of my motors, usually fixes any stubborn issues.