Thanks for the update Pete. I just ordered the Meridian 10cc so hopefully i'll have it ready for the motor when it comes in

like franco2fly was saying on the muffler,hold the head of the bolt with a screwdriver while tightening the nut..thats what i end up doing..i took mine off the engine and lightly clamped in a vise so i could do that ...it made it easier..cause every time you tighten the nut without holding the other end,it turns the bolt untightening the tail piece..seems to work well for me so far...

I actually did that, at every tight after every flight

I did a little bit of tuning on the engine last night and switched props. I put a APC 12x8 on it and the vibrations went WAY down and the sound levels also decreased quite a bit. I am thinking this engine likes to be loaded a bit to dampen the pulse. The only thing I am not happy with on this prop is the spoolup speed. it is a bit slow for my liking. 

I am getting these results on the ground:
Prop: APC 12x8
Idle: 2600
Full: 9200 

The other thing I noticed is that my HS needle seems to "wiggle" if you will and I can change the tune just by holding the needle. I can also see some bubles every now and then coming through the threads of the needle. almost as if the thread tolerances are too loose. Anyone else see this? I'll be putting some silicon line over the needle but this does not seem right to me.

I've got close to 20 tanks through the engine and I've been flying it on the Meridian using an APC 13X6.  I've switched over to Klotz oil still running 20:1.  I've tuned the low end in quite a bit from the stock setting and it now has a quick transition from idle to full without any stumbling or 4-stroking. I was afraid to lean the low end early-on but now after that many tanks it should be OK and it has much better transition response now.
The high end won't 4-stroke in the sir under load but when it's diving and unloading the prop it will 4-stroke a bit. Little movement on the high speed really does do a lot. I've not noticed any slop or leaking of the HS needle....yet.
Happy with the performance but I will be trying a Vess 13X6 to see what difference that makes. Also the exhaust residue has cleared up dramatically . It's a lot more than my other larger gassers but less than a typical glow.
I sealed up the stock muffler all around and it is holding up well....so far.   I also removed the plastic screen clunk and replaced it with a brass sintered clunk.

This is my best solution exhaust welding forever and no more problems

Yep That will darn sure do the job

Ken

Guys just get the copper heat gasket former and goop it up on all eaves including the threads on the screw it will hold. Good luck u get it at the automotive store

Now what the Pitts muffler I need  actually want to go inverted and put my 10cc on a hanger9 .46 mustange

It says in manual a. EVOM2  in cawl muffler wher can I get this guys?

my muffler seamed to seal up really well when i used permatex exhaust sealer..and i can get it to seal up really well on the extention to muffler,but the extention to engine seams a little tough..i get just a little small leak every time..i have a friend that has a machine shop and i think he has some copper shim in small sheets..i think i will get some from him and cut out a gasket and silicone it and try that..the copper should take the heat and want blow out like the regular exhaust material..make it a little larger on the sides where it want be to flimsy..

Okay I know but on the hanger 9 p-51 40 size it has in the manual a EVOM2 in cowl muffler for the 10gx so where is this muffler found please help

I don't believe it is available yet.

True it's not available yet but when can we get it and put it on alla  Manuel ?

Clicking Noise.
My engine has around 25+ tanks through it and it's now making a clicking noise when running and is noticeable at idle /lower rpm. There has always been a slight click when rotating by hand and it seems others have that as well but it just started to be very apparent when running.
Still running 20"1 and switched over to Klotz about 8 tanks ago. Running an APC 13X6 and just tried a Vess 13X6. Have the carb tuned for good transition on low and peak rpm to where it's not 4-stroking in the air but yet not too lean. The engine is still performing well but now with this clicking. When rotating by hand the click that was there is still there but not any louder. There is no end play or lateral play in the crank that I can feel.
Anyone else experiencing this yet?

Yes,<div>I hear a ticking when I'm at very slow idle</div><div>I mean almost ready to die</div>

I've thirty or more flights on mine and just into my second gal of fuel and note the same faint ticking as has always been there when grasping the prop hub between thumb and middle finger and twitching it back and forth at the bottom of the stroke. Not sure my ears could detect such ticking at idle.

A serious tick should be investigated.

Maidened my RV-4 and 10GX today and got some good stick time with the model/engine: some comments

- flying on a 10-6 prop, while I get the point of breaking the engine in, was pretty challenging. Not much power... required long takeoff runs, and being very careful to keep speed up in turns/loops/rolls and anything else. Iran 1 tank on the ground with the 10-6 and 1 tank in the air. I was pretty hesitant to try a second flight with the 10-6... simply put there wasn't much power there to save you should you need it.

- The 12-6 prop was night and day. easily 200 feet of vertical, takeoffs were under 10 feet. Much more pleased with the results here.

- engine never quit on me once in the air, its low speed was leaned out( turned in) about 2 screwdriver widths, The high end maybe a quarter turn. although I found the short landing gear of the plan and the 12-6 prop made for a couple prop strikes on landings. :-) that was my own fault though.



Good stuff, I'll update again in a month once I have a few more gallons through the plane.

I agree. Maybe Pete will chime in here and/or I will call Horizon and find out . It is apparent at idle.

Matthew,
You're asking too much from a 10 cc.
Here's my RV-4


I started flying it with a Super Tigre .91 nitro.

Turning 10,000 RPM Speeds were always below 40 mph (I've full telemetry in the bird) performance was Ok but not great.

Then I went to gas and a 15cc engine

Speeds went to 60 mph a 14/6 Vess prop turns a little over 8000 RPM

I believe the plane would fly a much better regime if a 20cc were in the nose. The 15cc gives good take off, climb and overall performance, but will not hold vertical climb for more than 5 seconds.

My observations FWIW is that the EVO 10cc, compares to a hot .61 engine but that's only with the best possible propeller match up. Unless you are talking a different RV-4, mine is the now discontinued
Great Planes 72" wing span plane.

KKKKFL

different rv-4, yours is the 1/4 scale i believe. Mine is the .40 size.

The engine with the 12-6 prop performed well I thought.

Yup<div>Mine is near 9 lbs.  A 20cc would be optimum</div>

You'd be doing a lot of flying to run a few gallons through it in a month. Took me three months to run one gal.

Most gas engines have roller bearings at the crank pin. They must have clearance for heat expansion and it is that slight bit of clearance that causes the ticking sound. If the ticking sound continues noticeably while running after the engine is up to operating temperature... then there might be an issue.

Yes I've been flying it a lot...almost every day/evening with a tank or two. I wanted to put it through its paces to see how both the engine and the plane(Meridian) would perform and hold up.
Nothing external causing the sound .  I don't want to open it up at this point but rather have Horizon look at it . Have to find out what they think and will do about it.