BiplaneCrasher

What batteries are you using for your gasser engine ignitions. I am having a time with my Roto35 and I feel that the battery I am running on the ignition module is inadequete, or bad gas. So tommorrow I will try a 1200MaH NiCad RC car battery with an adapter chord instead of a NmHi. The fella at RC Showcase said to try this. The other problem I had wis the electric starter I have is for smaller glow engines and too small to crank this one over.

Any ideas?

gunny11

My Feedback: (6)

http://www.hangtimes.com/rxpacks.html

I'm using the 1500 pack from NoBS batteries.

Gunny

Tired Old Man

My Feedback: (1)

Generally, I don't use anything larger than a 4.8v, 1,400mAh nicad battery. I have some Duralite Li-ons at 7.4v regulated to 5.4 volts, but they are only used where a weight reduction is needed.

You may want to check the timing on the engine if you are having a real difficult time starting it. I don't use starters at all, so I could not begin to comprehend all of the problem you are currently having. You may just need a stronger starter. Check the plug, too. It could be gummed up with old oil.

BiplaneCrasher

If this batteryworks this afternoon, I'll purchace a new Nicad and move on. Thanks!

Geistware

My Feedback: (16)

Basically you need a battery that can handle a 800ma load.
Most packs can do that. You can run it from a 600maH pack but you will only get about 30 minutes of flying time before recharging.

rmh

trouble starting the ROTO?
I have three of em and they all start very easily.
Is there a secret to it .
Not really.
I removed the Walbro "snap to off choke" contraption from the carburetor.
Instead, I made a very simple drag clutch on the choke - so that I can just turn the choke on or off as desired.
Just like any other gasser -- you choke and flip -watch to make sure the fuel comes to the carb-
engae ignition and in a few more flips, it will burp start.
Then stop.
open the choke -
reduce throttle to low idle and again flip -
that's it.
here are a couple of pictures.
One pic shows th little forked choke to throttle link-which I removed .
The other show the piece of silicone tube and washer and wheel collar, which make up the drag clutch -to hold the choke plate in any position as you select by turning the 1/16" rod attached.

BiplaneCrasher

Mr Hanson,

You have told me exactly what the boys at RC showcase said. I tried again tonight with the car pack. A fully charged 4.8vt 1500MaH pack with the proper connections of-course and no start. The last issue I think is that I have the wrong size fule line. I have the larger tygon running the gammet and I figuer it is leaking air. So off to the hobby shop for some tubing and t's. The clunk and tank lines are fine.

If you investigate my posts you'll see that I have my choke on a servo. I did it for fun really, but it closes all the way or opens all the way. What size tubing are you using? 1/16th tygon right? I have the next size 3/32 and that is most likely the reason I get no, or a slow fuel draw from the tank. Most of the time I work on the plane after working 14-16hrs for relaxation, and in a moment of ignorance I figuered a larger engine gets larger tubing, but gassers don't burn fuel as quickly as a nitro engine.

Do the ignition units fail? How do I know it's working?

Thanks!

Eddy.

David_Moen

Dick,

I like your choke setup! KISS principle at it's finest. It looks like there is a washer between the carb body and the piece of silicone, is that true? I am going to borrow your idea for my MVVS 26cc engine. I had a carb with the "automatic" choke on it and it started very easily, but it was way to large. I didn't want to burden my Ultra Stick with a choke servo, and starting an un-choked, cold engine is a tad tedious!

rmh

Eddy- nice linkage setup!-
the fuel line is really of no consequence--as long at it fits all points snugly - do not add any filters or fillers twixt the pick up and the carb.
a tee is fine .
The little LED should flash once,as you first turn on the power switch.
fuel should pull fairly easily on each flip of the prop --with choke fully engaged.
spark can easily be read on this system by dropping plug into the cap (held upside down) whilst turning prop thru a revolution.
David - yes a flatwasher --then the heavy wall tubing, compressed about 15% and held with a wheel collar.
A short , heavy spring would also work-in place of the tubing.

kevin mcgrath

My Feedback: (1)

I have two blue head ROTO 35cc units and they are reliable easy starters. I doubt its the batterys or ignition unit........pull the plug.......you are getting a spark or not..........this engine really needs to start WET.
Dick.........did you close up the holes on the choke plate at all by any chance? I find cold starts while reliable, take 15 flips or so full choke,full throttle,ignition on to first burp.......I was going to solder up the large hole in the plate and start back up with a 1/16 bit..........I like your choke link! so simple!

rmh

I did not solder mine -but soldering the hole then redrilling to say-- 1/32 is a good idea.

BiplaneCrasher

Like I said before I work on the planes after I come home from work and mostly tired. But today, eventhough I worked fourteen hours, I had the guts to look and see if I had the polarity correct going from/to the ignition. I had the wires reversed. I will try again over the weekend. And post. I am sure this will fix the problem.

BiplaneCrasher

Yippy! I got it runnin' after all. I re-lined the fuel lines and slapped a 1100MaH NiCad in the fuse and after a momentary twist of a starter it fired up. The size I have in it now is 1/16th Tygon. I would still not start after this by hand. I have a long lead of fuel tubing so that I can see the fuel moving thru the line and it also alows me to remove the fuel tank with out getting fuel all over inside the fuse..

The engine sounds great and it realy does sip fuel. I had the 32 oz tank full and it ran at 3/4 throttle for 10min at least and the tank level barely changed. Boy, this engine moves some wind!

BiplaneCrasher

Here is a pic of the Roto35 running. After getting it started I had no problem tuning it. Compared to a nitro engine the tunig adjustments are quicker. Maybe 5-10 seconds after an input to the high or low needles. Because I have a long fuel lead, I have an extended time of primiming, so I'll just use a starter until she breaks in, or I find another solution.

heres a pic,