garyFL

Tom, thanks for all the information. I don't mind putting in the time necessary to get my engine running right. I have it mounted on an engine test stand and hope to get it all set and ready to go in the next couple days.Again, thanks for your help. - Gary

garyFL

Well, Horizon Hobby sent me a 10% off on all items so I ordered the 777. I ended up getting an additional $42 off with a coupon from Horizon and cash back from my credit card. I ended up paying 1115.99. I'm very happy with that price and the fact that I now have a 777 and a 735. I plan to put the 735 on a Giant Stik and the 777 on a Hanger 9 Corsair. I haven't purchased the Corsair yet.

On another note, I saw where the 160 gas engine has been discontinued. Has anyone else heard that?

I would like to thank all members on this site for their valuable information. I would never have purchased a radial had it not been for the support you folks offer. Hopefully I can help others when I gain enough experience with these radial engines. Many Thanks. Gary

redball8

My Feedback: (128)

Code for 10 percent off is RUSHGIFTS14. Good until the 17th.

garyFL

Thanks for posting that redball8. Get an additional $10 off on order of $49 or more. Code: XTRA10OFF

BobH

My Feedback: (2)

They are still selling the 160. I have one and it runs great..

garyFL

I bet it does!!! The reason I brought this up is for people who want one might check and confirm the info and if true might want to order one while HH still has some in stock. I got that info from the Q&A for the 160. What size plane do you have that monster installed in? I really love the sound of the 160. If they are still available this summer I will probably get one. - Gary

Straightleg

Hello guys !

I have a problem with my 7-77. I will not suck enough fuel at WOT ! It increases a little, and then slowly dies. I have tried everything ( yes, I have wide I.D. fuel line and yes, it is broken in).
The only thing that works, is to choke the carb with my finger tip. Eighter there is something wrong with my carb. or I have overseen something. Pls advice !

regards,

terje [Norway]

BobH

My Feedback: (2)

I had the same issue with mine. What I think is that engine will only run full throttle at some point before wide open. I adjusted my throttle curve on my Tx to match when the engine was running its fastest. That seems to work for me.

tsnaylor1964

BobH,
I also had that problem when I was breaking in the 77 on the bench. I knew it was getting enough fuel because I could see fuel in the line to the carb and no air bubbles either. It turned out that my battery for the onboard glow was too small and the plugs were not staying lit. (those 7 plugs draw allot of current) Once I made a battery pack with enough amps it took care of the problem. I think another contributing factor was that I broke it in with just methanol and oil mix and no nitro. I just am in the process of my break-in with the 99 and I used 7% nitro and did not experience that problem with dying like that. Now that it is near break-in I will go back to the methanol and 7% oil mix with no nitro.
Tom

BobH

My Feedback: (2)

I have a 5000mah battery and mcdanials igniter. Plus I did use 5? % nitro. So I think my issue was related to the carb.

BobH

My Feedback: (2)

I have a 5000mah battery and mcdanials igniter. Plus I did use 5? % nitro. So I think my issue was related to the carb.

redball8

My Feedback: (128)

Tank height? Raising it will give more fuel flow, all other things constant.

Straightleg

Ok, BobH, that is a solution, but I want the Whole potensial of the engine. On a Moki 215/250 you can not have WOT, because of the geometri of the Walbro carb with this engine, but the 7-77 Accepts WOT, as long as it gets enough fuel.
Here is my set up and what is happening:
Prop 24x12
Pure methanol With 4% Aerosave oil (recommended by Seidel himself and Works perfectly With my Seidel 7-250 glow)
Everything works perfect up to 4500 rpm. More throttle, and the engine dies. With the exact finger tip choking, the engine comes to live and puts out steady 5300 revs.
I had some fuel starvation problems on my Seidel/UMS 7-250 Gas (w/walbro) because of weak impulses from the inlet manifold pressure.( no separate impuls pump as on Moki) This problem was solved With a fuel pump.
Well, I am still empty for new ideas !

/terje

Straightleg

Tried that, redball !

Maxam

My Feedback: (62)

Terje, At full throttle on the transmitter, my carb is open 3/4. Like I do on my moki's. Much better fuel draw. You also might have a blockage in the needle valve area. -Tom

Straightleg

Hey Tom ! Ok, but the difference here is that you get full Power With Moki at 3/4 throttle. As I decribed above,I got 5300 With a little "cheating", and that is a big difference With 24x12 prop, especially if you want to fly IMAC.
I am not sure what the throttle opening is at 4500, but a little over half, I Guess!. Anyway, I want the full potensial of my 7-77 !! (lol) , and I also intend to find out !! I suspect that the carb is made by a blacksmith, and not the same quality as a OS carb. According to the test paper that followes the engine, it ran at 5600 at the factory. I really do not understand this.
The carb is cleaned and blown dry with air.

/terje

kurrikan

Hi ,i have the 7 35 cc radial.I would like to know your opinion abou to install the 7 35 into the 30cc p 47 from hangar 9.Do you think this engine has the enough power to pull up that plane wiht autority??


sorry for my english

Straightleg

If you ask me, I would say no. I do not have any experience With the 7-35, but a fellow Club member has one, and the Power of this engine did not impress me. I believe it is to much internal restistance or friction in this small radial. At least, it can not be compared With a modern two stroke 35cc engine. I see on the specification of the kit that it weights 8 kg +, and that is too though for the 7-35, but I could be wrong...

Maxam

My Feedback: (62)

Terje, What is your oil %? The less oil, the richer! -Tom

Straightleg

Tom, as stated above, I run on pure methanol and 4% Aerosave oil. There is no difference if the main needle is three or ten turns out !

/terje

Maxam

My Feedback: (62)

4% oil!!!!! I am running 9% . That takes guts! The minimum in the directions is 6 or 7%.

Straightleg

He he, maybe ! Well, I do not allways listen to manuals, but I read them. Manuals must take in consideration all users and conditions all over the world, to not get sued. Especially propeller recomandations, is often very doubtful.
Manuals write rpm range from 1000 to 6000.(radials) People put on so small propellers, so they Reach 6000, and believe they get more Power. This is not true, radials love low rpm's
Anyway, regarding fuel/oil mixture: I have ran my gas radials on 2% high quality oil for many years ( at least 200 liters) even though the manuals says 4%. No problems, what so ever. The designer of the Evolution engines says 4% high quality oil.on glow, and I use that. Same thing here, no problems.

/terje

mogman

Hi guys,
An update on the gas/ignition conversion of my 7-77
Adrian at CH sent me a carb adaptor and a couple of Walbro carbs to try out.
I finally got time to run the engine.
First of all I had to use some longer stand-offs so the Walbro would be clear of the engine mounting plate.

I'm using reg, gas with a (approx) 20;1 mix. As there are no rod bearings in this engine, I hope I erred on the side of enough, or too much oil.

Stared the engine, idle at 16-1800, top end 55-5600 using a 22/12 prop.
I haven't done any fine tuning yet, as I wanted to see how this would work out. Transition is crisp and instantaneous!!! I ran the engine full throttle for a few seconds, let it idle for about 15-20 secs, shut it off and I can comfortably put my hand on the cylinders....quite cool in fact.
The plugs are a bit black, but as I said this is just the initial running.

I'll run it some more, the pull the engine off the stand, and remove the back plate and have a look inside to see how oily it is....or not, and go from there.

Cheers,
Dave.

Maxam

My Feedback: (62)

Terje, I arrived at the 9% oil amount because at that concentration the oil dripping out of the cam housing is crystal clear. Less than that is gets dark indicating wear. My Moki's I run 44:1 oil and the exhaust is clean and the plugs are all brown.

Linkan2

Merry Christmas to you all.
I hope get a lot of time with your loved ones.
as we say in Sweden God Jul
lars