Batteries are for driving servos. :).

drac:
I am using one of the headers here. Specifically I use # HAT 822:
http://www.centralhobbies.com/Exhaust/headers.html

After seeing your reply it appears as though we are using different units. Is your unit different than the one on the link above?

Ed

The only problem I have with YS is the lack of mufflers and headers for the larger engines. It seems like the only thing available is Hatori canisters or Pitts style wrap-around. Any suggestions? I've thought about having an adapter made to mate with the many gas engine mufflers.

I haven't come across anything else. Adapting a different muffler should be OK, but why wouldn't the Pitts style or canister work for you?

This is the YS header.

Scott,
This has always worked for me…
Wrap your muffler bolts in teflon plumbers tape,assemble the header but don't tighten the bolts fully.
Start the engine and warm it up
After it's pretty warm fully tighten the header bolts all the way and you should be good to go.

Hope this helps,
paul

Yessir. I don't recall the name of the manufacturer. A copper gasket onto an internal wrenching threaded male steel fitting through the header and iinstalled into the female threads of the aluminum motor head using a large allen wrench. An internal wrenching aluminum threaded cover was then installed on the header to seal the deal. Always tight when cool, gradually loosening when motor gets hot. Mine kept coming loose on my 140 Sport and 140L motors and after repeated attempts to tighten when hot, the wrenching forces exerted on the aluminum cover plate with the large allen wrench would ruin the cover plate. If not careful, could ruin the female threads on the motor head.

Whoa! I'm not familiar with that one!

The thread tape must be Teflon. I'm very surprised that no one else has chimed in to say it works and is the simplest solution. Just 3 or so wraps around the threads is all it takes. Good luck.

I didn't know there was any other type. PTFE is all I've used for 30+ years. Now that makes me sound old. Lol.

1 or 2 others have mentioned it.

Thanks all for the advice.

Drill and lockwire.

The first plane I put it on was a Aero-Works .90-1.20 Yak which was the only reasonable priced ARF that I could find in the correct weight range. The canister wouldn't fit and the Pitts requires the motor to be mounted inverted. I had to backset the firewall 1/2" to get the engine on a Hyde mount to fit in the cowl. I don't think I'm buying any more ARFs. I'll build my own to get the size and weight range I want, the color scheme I like, and it will be built stronger and more durable.

Mounting inverted is the easiest way to fit most engines. YS's don't have any issues being inverted. I fitted a DZ140 to a 65" Seagull Seafury ARF. The engine is mounted inverted on a Dubro soft mount with a Slimline Pitts muffler. Sounds great and runs perfectly.

I use the black high temp rtv gasket maker. I've found it VERY important to make sure there is NO trace of oil on the parts. I use a can of brake parts cleaner to degrease the parts. It's relatively cheap and it very convenient to use.

Ken

Hi Ken,

Silicon doesn't seem to work too well. I have taken Bryans advice and made an extension so to be able to get some more leverage. It's only had 27 flights since, but so far so good. When I get to 50, I'll start get hopefull.

OK, every situation is a bit different. I've had reasonable luck with the RTV but like I said ALL oil has to be removed for the silicone to bond. FWIW you can reuse the copper washers many times if you heat the washer red hot with a torch and let it cool naturally/slowly. This is an annealing process and it works. If you have an old gasket laying around, feel how stiff it is before the process and after. It will be "dead soft" after annealing.

Sounds like you are on the right path with your header at the present time. I hope it stays tight for you. We all learn when something goes right...and wrong!

Ken

Yep, know all about annealing. Fitter and turner by trade for the last 25 years.

Unless the copper washers get damaged, there is no need to replace them, ever. There is no need to anneal them either as they are already soft. If they weren't soft, they wouldn't work as a gasket.
The flange that screws into the head doesn't come loose , so the copper washers don't get taken off at all.

Another 4 flights today, which makes it 33.

44 flights now and all is good.

I have a couple of comps next weekend, so I may check just to make sure it will be OK for the comps. If it's going to come loose, it will during a comp. Lol.

That is the natural order of things. LOL:rolleyes:

An update on the loose header.

Since tightening with a 6" extension on the spanner, I have had no problem with the header coming loose. Probably around 250 flights.

It just needed a little extra muscle.