SWORDSN

My Feedback: (13)

The carb fuel inlet seems to be pointed in the wrong direction.Will that be a problem?Can the inlet be turned?

njmheli

Hi Swordsn.

Thank you for your comment...............yes,noticed that when I received the carb........The FG 84 which I have ( that's going in my H9 Corsair ) has the fuel inlet pointing AFT,in line with the velocity stack.

In the application for fitting this carb to the 7-77.luckily for me,it was produced pointing FWD ( as you saw ),otherwise,it would have caused a problem,in as much it would be facing the 7-77's mounting flange..........The fuel inlet on the carb could be fixed anywhere in a 180 degree arc,from where it is ( this would give no problems with fitting the fuel tube to it or problems with the inlet on the stand off's )...........I did think of moving it 90 degress,but if I had broken it,I don't have a spare !!! It is a interference fit on a brass splined tube into the carb...........

IMO,as far as the carb is concerned,it doesn't matter at which direction the fuel enters.....................just that it gets the fuel !!!!

On my test stand,the tank is sited well below the C/L of the carb,the internal pump on the carb appears to be quite good ( Saito in their instructions for the FG 84 use the words "PUMP NOT TOO STRONG",so place tank near as possible to engine !!! ).............but as said the fuel tank is also pressure fed,which I'm sure helps the pump ..?

The tank / fuel lines,were as stated sucked dry by the pump / pressure feed !!!!

A lovely radial engine,I must say...............to date very,very pleased with it and after all the conversions I have carried out on it................Will MISS all of the "AFTER-RUN" procedure now it's running on gas ..........

Kind regards..................Nick (UK).

njmheli

Duplicate post now deleted............don't know how that happened...........

Nick (UK).

chorner

Finally had the chance to run my Evo 7-77, and wow does it have some guts on CDI. I'm using 20% nitro/9% oil which is a little bit on the high-side but it's the closest I'm able to get for now to something with the right amount of oil. Haven't found a good source of methanol yet, but will dilute my fuel when I get some good stuff.

Anyhow, runs strongly and I've sealed up all the intake tubes, as well as the backplate a bit better (my o-ring perhaps wasn't seating right/crushed it a bit) so it's not messy at all now outside of the mess on the driveway ha ha

On CDI, after my 3rd tank of fuel using a Mejzlik 22x12, at 3/4 throttle I was pulling over 6,000rpms. At one point I hit up to ~6,300 and had to back off. Seems the higher nitro content combined with CDI really rips the prop on this thing. Will switch to a 24x10 after another 30 mins of run time and keep the RPMS down. My engine was spitting fuel out at the recommended factory needle settings, but left it there to ensure I was cleaning out the engine from debris. Lots of dark oil, next time I'll need to protect the driveway a bit better and lean out the low-end

Posted a quick YouTube video:
https://www.youtube.com/watch?v=PlSZiQgeTnM

tilefly

I have been following this thread for about a year,because about a year ago I bought my Evo 777.unlike other posts I've read my motor was not crunchy when I spun it by hand,it was a little stiff but very smooth.have completed three hours bench time and mounted on an ECOM 88 inch model 44 racer.after break and I am now running 9% nitro 9% oil ,for a prop I am using a zoar 24x10 old timey scale prop.I was spinning 5200 rpm just before Maiden.the plane weighs about 25 pounds and it just seems like it barely flew. I needed full throttle the whole time.I am fairly new to giant scale planes perhaps a different prop would help?maybe try to get more rpms from the motor?any ideas or input would be great.Thanks*this is also my first radial.

chorner

Tilefly, maybe others can chime in too but that may be a bit too much oil for running after break in. Should be down around 7% maybe even a touch lower. Also that prop may not be that efficient, as well make sure the engine is tuned properly (transitions crisply for low to high rpm and drops right back down to idle without sagging or hanging at a higher rpm before dropping etc). Are you running onboard glow? I'd for sure run at least a proper variable onboard glow system to ensure you don't drop any cylinders while running personally. On that note I'd also make sure all the plugs are good.

not sure about that prop in general but those RPMs seem about 300 or so on the low side for that size prop. I just got my engime but after running it now for a couple hours I have a good idea of the power and rpm range you want to get on the ground. You should be able to pull around 5,500rpm peak on the ground at minimum for crisp response with whatever prop you chose to run.

tilefly

thanks for your input Chorner! How do you feel about the 24 x 10 prop for that airplane ? Maybe a smaller prop with more pitch?

chorner

I think in your case a 22x12 for a 25lbs plane would suit it much better than a 24x10

cymaz

I run a Zoar pja prop. Very good. Try just a few clicks richer at WOT. I was surprised what a difference that makes. I use a Sonic Tronics on board glow system....brilliant.

BobH

My Feedback: (2)

more pitch and more rpms would give you more speed.. So a lower diameter prop.. maybe 22-12?

cymaz

I had success with a 22x10 for a year. The motor has really loosened up nicely....24x10 now

tilefly

I think I will try a 22 x12.Thanks all.

Linkan2

oh well now I have been waiting for parts for my UMS / evo since February 5.
Parts are paid so they are well just wait, what do you think.
Well I've had this on speech before.
But we live in 2015 with the internet and trade across the globe.

parts are ordered in the uk weelspin, do not think broblemet is with them
It's UMS (does not respond to e-mail) or Horizon hobby that does not release the parts.
I want to repair my engine not to ship to the other side of the earth for lot of money

These engines have a good quality yes but there must be parts available on the market.
If not, they will harm the reputation of these engines.
they are other brands that have parts get
yes I let litte sour they get it right sometimes, are those who have the worse
Lars

cymaz

OK...a bit off piste. No flying Sunday, so I started up this beastie
https://www.youtube.com/watch?v=90w6Aa4qlLM

CRG

My Feedback: (3)

Lars,

Which parts are you waiting for, and what has Wheelspin told you about your order status?

Craig
Horizon Hobby

Linkan2

Good evening Craig
Those who I am waiting for a cam disc EVO73522A
what weelspin said about the order status = If Evolution Have No stock .... We Can not ship you the party!
I pressed the weelspin to get the parts, then get well weespin press & UMS ??

3 months is a long time to wait on paid parts.
honestly Craig when all parts will come out on the market?

CRG

My Feedback: (3)

Lars,

These parts are available, but no order has been placed. Please ask Wheelspin to confirm that they have placed the order, otherwise I would recommend ordering the part directly with Horizon DE.

Craig

badgerord

My Feedback: (6)

Is there anyone in the US that is selling a Walbro conversion for the 7-77?

Linkan2

I wetting is not how hard they shall be to obtain parts.
Horizon example, has no parts, do you have contact with each other?
wheelspin responded like this.
The Hi Lasse,
Hi Craig,
This party is definitely on back order with Horizon UK ..
I have chased them again today and They have advised They think it is now discontinued.
How do you want us to Proceed? Cancel The Whole orders or ship the one item we'll have in stock?
Lars

CRG

My Feedback: (3)

Lars, the parts are certainly available. Please contact me via private message here and we shall get this resolved.

Craig

chorner

So luckily, I have two Evolution 7-77 motors in my possession. I've found by comparing the two closely, that one of them was supplied with no o-rings on any of the intake tubes... no wonder that engine was leaky as all hell and I had to use engine sealant around every intake tube top and bottom.

Just a heads-up for guys buying the EVO 7-77... take a good thorough look over the engine before accepting the new $1,300 + engine.

Also, on my 2nd radial engine ordered directly from Horizon, the front-cover where the 'Evolution Radial' is stamped is not aligned the same as most other EVO 7-77's I've seen where the 'Evolution Radial' is below cylinder #1. On mine, the UT 7-77 is below and in line with cylinder #1.

... look over your engines carefully guys. Seems the QC department falls asleep sometimes.

CH Ignitions

My Feedback: (11)

We do offer that...but for couple months I will not take orders.
Have couple things that I want to iron out.
The new box CDi and then to try a different idea on the carb to pump fuel by it self.
The FG84 or the other carb I use run fine on stand as long you do not move the tank position.
Once you go lower to simulate a pull up, engine dies.
I have a new idea, and I will have a 7-77 to prove if it works or not.
The conversion made before run on reg carb with EXH. pressured tank.
The second is with electric fuel pump from Vogelsang , pump used on Moki Engines.


Adrian

Heli-NuBee

This is probably not the correct place for this but I am considering selling my UMS 7-77. The engine only has seven flights on it and is in excellent condition. The Microsens on board glow system and balancer and the exhaust ring will be with the engine. Total cost of the engine and extras was almost $2,000. I have had the engine in a Black Horse Corsair and the engine has performed well but the landing gear on the Corsair has been a serious problem. I used a Lado gear on the plane and both the gear and mounting plate are just too weak for this airplane. The gear has torn out of the wing three times out of seven flights and I am growing tired of repairing the plane. Any thoughts out there?

Best wishes and good safe flying.

Heli-NuBee (AKA Roger the radial rabbit)

BobH

My Feedback: (2)

Wouldn't it be better to change out the gear for either Robert, century jer, or Sierra? Is that possible? If you sell the engine you are still going to have a plane with not so good gear.

Heli-NuBee

Hey BobH, I considered those options but it would require considerable rework and expense. I have been down that road twice already and am getting tired of throwing good money after bad. If I sell the engine, I will probably just scrap the plane.

Heli-NuBee (AKA Roger the radial rabbit)