Maxam

My Feedback: (62)

air tool and after run same thing. No point putting in carb. Same place as follower hole

badangle

My Feedback: (1)

Great. ..saves me a step

j lauria

I sold my nonstarting 9-99 to a motor tinkerer after it was returned to me by Horizon. Horizon wanted $500.00 to replace the bearings and $250.00 per cylinder to replace the eight cylinders with no compression. The party I sold it to cleaned the bearings and cam by pacing them in an ultrasonic cleaner for an hour. He replaced the rings in all cylinders and replaced one cylinder. The engine is running well now. He found it impossible to deal with Horizon and had to obtain the parts from India. I currently have two twins and several single cylinder engines from Horizon, along with a lot of other stuff. I question their commitment to customer service. I regret that I built a beautiful Stearman around the engine only to have the engine fail after 12 flights because it wouldn't start.. The cause of the massive corrosion was probably due to the unburned fuel in it due to the inability to start it. The engine had been treated to the usual flushing with after run oil and air tool oil after each days flying. An expensive lesson!!!.

TFF

Over on the Scale section, abufletcher had the same thing happen. He lives in Japan so sending it to India was easy as he is not an engine tinkerer. The tariff was higher than his repair. What seems to be required of this engine is no sitting. It almost needs to be run weekly just so corrosion and gummed oil never happens. Defiantly monthly with no exceptions. I have to say I let a YS 110 sit for a year amd it made the same mess. Flown for years no problems, and life got in the way and it required everything.

barzini

My Feedback: (4)

Does anyone know why Horizon will not sell parts to its customers for the Evolution Radials? Especially for customers with engines out of warranty.This is very unusual.

capnpaul

I think it might go right back to the manufacturer,Because i don't see anyone worldwide selling parts.

Maxam

My Feedback: (62)

I have bought parts from UMS. Had the parts within 10 days. -Tom

badangle

My Feedback: (1)

Can anyone think of a way to decrease Propeller diameter without harming the engine ?
I am concerned with ground clearance

Maxam

My Feedback: (62)

Increase pitch and/ or three blade. More info needed. Which engine and what diameter needed to clear the ground. -Tom

tsnaylor1964

Hey Tom I tried to find the UMS site for spare parts but no luck. Do you have a link for that?
Thanks,
Tom

Maxam

My Feedback: (62)

I E-mailed them requesting the parts i needed. it has been over a year. -Tom

badangle

My Feedback: (1)

77" stearman from ziroli plans...should have 18" propeller if using 35cc gas....but I'm using evolution 7-77 with 22 " propeller..worried about propeller hitting the ground...have bigger tires but landing gear is s compressible

Maxam

My Feedback: (62)

22x14. i use a 25x12 on my 777.

Papasal

Tom, my name is Papa Sal. I have been following this thread from page one. Thank you for all of your knowledge and hard work. I know this is a glow forum, but would like your opinion on using an Evolution 7-160 gas in a new Pilot 33% Yak 55M . It has a 107" wing span and weighs 29lbs per specs from pilot. I really want to stay with gasoline if at all possible. I'm not a 3D pilot, but want this plane to perform. Any help would be great. Thanks
Papa Sal

Maxam

My Feedback: (62)

Papa, I have had that very engine in a 37% Yak 55 SP swinging a 28x14. You will have a nice solid combination. -Tom

Papasal

Thank you for the quick response Tom. I know these fourms are a lot of work, but I think it would be great if you started a gas radial thread too. I'm sure the same care and maintenance applies, but I was concerned when you said the head and cylinder leak is common to the gasser. Sal

Maxam

My Feedback: (62)

Yes, a few people had that problem with the head/cylinder with the 160. They do run well. The Moki 150/180 suffer poor fuel distribution but the 215/250 Moki's are excellent engines. I now have the 215 in my 37% Yak and that is perfect!

badangle

My Feedback: (1)

Anyone found a good starter battery for a 7 cyl radial ?...TEENERGY battery not available. At this time....built a pack of 8 4000mah. Ni-mh batteries. But it cumbersome

Linkan2

Hello
I want to ask you who have 7-35 and 7-77 if you have experienced a radial internal clearance on the crankshaft.
When you wiggle the propeller ???
Lars

Maxam

My Feedback: (62)

Lars, you might be feeling the gap in the gear teeth that drives the cam ring. If you turn the prop a very tiny amount you should feel the tinest amount of play between the crank pin and master rod.

Linkan2

I suspect that there are gaps in the rear bearing
they are mounted in a holder that sits in the front cover.
I think they may be the holder front cover

barzini

My Feedback: (4)

Has anyone on this forum removed the front bearings and cam cluster from a 7-77 or 9-99? Im sure there is timing involved but theres no service manual available?
Thanks,Tony

Linkan2

Hi Tony
This is a manual on the setting of the cam ring.
It is for 7-35 but it is enough to use for those Störe engineA also
Lars

tih

My Feedback: (1)

Lars: do you have any other documentation for the 7-35?

Linkan2

No I have not.
I have a explosive sketch of 7-35 ???