Helibug HB6-RCT7 Mods

[Doozer]

I've decided to start a new thread for this mod because it's pretty important and I don't want it to get lost in the build thread. I will link it there though.

Lately, the last year or so, I've been a strong opponent of unnecessary modding. However, some modding/upgrading is necessary sometimes. This is the case with the Walbro 603 carb that comes stock with the G230rc engines. So here's what I did and why.

It seems that the stock insulator block for the carb on these engines is suspect. Evidently, it warps over time. Mine was slightly and was causing an air leak that was making the engine hard to tune. Air leaks can make an engine run lean. Too many lean runs and your engine is toast. One lean run can cause enough damage to ground your heli. It just depends on how lean it gets.

I also purchased and installed a new Walbro WT-813 Carb, and a K&N Pancake air filter, since the stock one was allowing dirt to enter the engine.

I don't have time to post any pictures right now but I will leave a link up to the part on Daves Discount Motors site until I can get some images posted.

www.davesmotors.com/s.nl/c.885035/n.1/it.A/id.855/.f

[Doozer]

New carb installed;
New K&N Filter installed;
New intake manifold installed;
Paper exhaust manifold gasket removed, PC Farenheit installed;

Huge difference. Low temps after climb outs, more quiet, no sag in power on spool up. I'm guessing I had some air leaks because the needles stayed consistent. With the needles 1 3/8 out on the new carb, I actually had some smoke. This tells me I was probably running somewhat lean before. However, the piston skirt looks very good and the piston head looks like one that used a non-synthetic to break in, which I did. So it looks normal.

All is well.

[Doozer]

This is the experience all the other gasser guys are talking about! Second tank through with the new mods, and now I'm starting to understand why people mod this engine. It's almost a must, but if you have no comparison, you might not know you need to. Because of the mods, I'm really starting to understand how pitch and throttle relate in curves. Before I got everything tightened up, my needles were all over the place.... My pitch was wrong as well.

Once I got the needles close, it was like a smack in the face.... "ohhh so this is what they mean." I really heard the missing, and could see the tail kicking in correspondence to the missing. I heard the engine become "happy."

It was a good thing I had the needles running pretty rich with the old carb or I think I would have killed this engine. I think checking the piston and breaking the original seal on the exhaust manifold was causing major issues as well. I believe, if you're not careful breaking that seal, you either need to replace it with another, or use something better. For the G230rc that comes with the 603 carb, installing a new carb, the billet manifold, and some PC Fahrenheit on the exhaust manifold, at least, are must in my book.

[Dave]

Just for the heck of it Doozer what would the cost of an engine replacement and then the mod have been verses just the cost of the mod?

Dave

[Doozer]

Well, facing the prospect of another 3 gallon break in would be one reason I wouldn't want to replace the engine. As you may have read in the build thread, these things sip fuel. Three gallons is a lot of air time (approximately 4.5 hours air time per gallon). Getting 20 minutes here 30 minutes there has made the break in go slowly. So there would have been another time sink/cost. But to be honest Dave, parts for these engines are cheap. The engine was $200, and I would have still replaced the 603 carb, stock manifold, and air filter anyway.

Trust me, I thought about replacing the engine, but when I checked the piston and piston head before I sealed it up with PC Fahrenheit, it looked very good. If there had been any scuffing or scoring of the piston, I would have replaced the engine. These mods are all external mods, so scrapping the entire engine was never really a good choice.

I did see some scratching, albeit a very small amount, but I attributed this to the flying environment. The desert is dusty/rocky/sandy. This is why I bought the better air filtration system. The stock system has too many points from which dirt or sand can enter. Now you may be saying, "I fly my nitro without an air filter, how come I can't fly this engine without one. Look at the placement of the nitro carb vs. the gas carb. The nitro carb sits directly below a fan. Dust and dirt have very little chance of entering the engine. The fan acts as an air curtain. The gas engine carb sits off to the side and has no air curtain and is the direct line of fire of dirt and debris that's being sucked up by your blades. One over sized grain of sand, one little tiny rock, and the damage could be catastrophic.

People will sell you anything to make a buck. The 603 carb having a "flat spot" is a well known issue. However, If you are unaware that the 603 carb is not ideal for flying then you'll find out when the power sags, and that may be too late. I was lucky enough to catch a post on heli freak about a flat spot in power. When I experienced it first hand, I knew what it was because I read about it. This is kind of why I'm posting this thread separate from the build. I don't want it to get lost in all that information.


If I were to do it all over again, this is what I would buy:
www.davesmotors.com/s.nl/c.885035/n.1/it.A/id.4628/.f
With this engine, you have the option of buying the 813 carb straight away. I'd still get the billet manifold as the plastic manifolds tend to warp.

[Doozer]

Got tired of this:


and this:



So I made these:


If you have to fly where you take off and land on pavement or cement, your skids suffer some wear and tear. So I made these "Skid Socks" out of bicycle tire inner-tube. Not refined yet but they hold up well. By "not refined" I mean they are pretty ugly. On smoother surfaces like concrete, they kind of act like skates, but on pavement they are rock solid.

Any thoughts, ideas... ray?