Maxam

My Feedback: (62)

Tug, I prefer at least 9% oil. Contact klotz so you will be sent the correct oil.
Sess, I do not run exhaust pressure. I have found the corrosives in it are hard on the engine. -Tom

Pete S-RCU

Maxim, I have the Evo7260 gas engine, will a Sullivan Megatron starter turn over a 260 cc engine?
I'm trying to find a starter, not very many choices to choose from.

Tugsorus

Thanks Tom Im going to use klotz super tecnoplate 2 stroke from what I can find out its compatible with methonal tug

Ozflyboi

Hi Guys,

Just thought I would share with you some photos of my Evo 7-35 I recently installed and test flown in my Great Planes Waco.

The model seems to fly in a scale like fashion with this motor and I look forward to entering into some scale flying events over here in Oz.

I am running with a biela 17x8 propeller and with cowling removed at least initially.

Only problem I am having is I am losing pushrods and I suspect this is due to over revving causing valve bounce. Are any of you able to assist or provide your own experiences with this motor?

Perhaps I just need to operate lower throttle end point to avoid this from happening?

Maxam

My Feedback: (62)

OZ, Use a larger propeller such as an 17x10 or 18x8.
Pete, use the Miller reduction on a regular dynatron. The direct drive starters spin too fast. The Miller "Persuader" is an excellent unit.

Hey guys, I think Oz' plane looks fantastic. The engine is just the right scale too.-Tom

j lauria

[QUOTE=montt00;12206087]After reading the comments, i have decided to build the Stearman 87 inch from Ziroli.. and alspo trying to build light withpout
Hello Montoo,

I have built the Ziroli 87 inch Stearman. I have an Evo 9-99 in it. It weighs about 30 pounds. It is an excellent flyer. It flies very realistically with the 9-99 and looks great. See my pics on rcscalebuilder.

John

Corsair Bill

Maxam (Tom) have ordered the OS 7mm bore carb for a 7-77, and the adapter from Adrian. I'm thinking to leave the stock carb on until after break in procedure then going to the OS. Your thoughts? Thanks Bill

Maxam

My Feedback: (62)

I would use the OS so the engine can be richened properly during break in.

Corsair Bill

Thanks Tom, do you have recommended settings for high and low needles? Both 2 turns out maybe?

slskn

My Feedback: (4)

My Flair Stearman wt. is 35+ lbs. and the 7-77 flies it Great!! also My Ziroli Corsia wt. is 36 lbs. and the 9-99 flies it fairly scale enough for me, and the one who asked about the Electric starter, my sullivan Dynatron with the 3in. belt drive gear reducer made from miller r/c products works great on my Evo 9-99.

Maxam

My Feedback: (62)

Corsair, I do not pay attention to # of turns on carbs. I listen intently to the engine and tune to highest rpm then back off a number of clicks then observe the engines behavior during throttle changes. During early break in it is initially nearly slobbery rich. -Tom

Corsair Bill

Thanks Tom!!!

montt00

Hello
I think i am put on the wrong leg, but iīm not sure. Can the the Ziroli Stearman 87 inch fly with the Evo 7-77 or must it be the 9-99?
I'm a little concerned that i have ordered the wrong plan.
Regards,
Timo

mogman

Finally got around to taking a couple of pics of the giant Aeromaster with the 7-77.
Gas and ign. conversion by Adrian at CH.
Plane weighs 22 lbs, 22-12 prop turning at 5600 on the ground and flies very well. Has a good turn of speed, but is just about perfect at about 1/2 throttle.

Cheers,
Dave.

Maxam

My Feedback: (62)

Mont, refer to post 1176 -Tom

Maxam

My Feedback: (62)

Wear that engine out Mogman! I would use a bigger prop!

mogman

Tom, not quite sure what you mean by "wear that engine out"
Because I'm using gas or???????......I'm using 20:1 mix.

I tried a 24-12 but it only turned about 44-4500

Cheers,
Dave.

Maxam

My Feedback: (62)

I mean have fun with it, fly it a lot, enjoy it! No negativity meant at all. The rpm you mentioned with the 24x12 is actually ideal in a scale sense.

mogman

Thank you, Tom, I suspected that was what you meant.

I'll stay with the 22-12 as I only use full throttle for take off and the occasional loop now and then.
Most of the flight is at or below 1/2 throttle.

I even had one spectator ask me if it was electric as it is so quiet!

After a few more flights I'm going to pull the back off the engine and see how things look inside regarding enough oil etc....(20:1 Stihl ultra) I seem to be getting some lube pushing up past the cam lifters so good lubrication there, I think.

As an aside, I recently acquired a brand new, un run 7-260 serial # 00002 for less than half price. However it did not come with the wiring harness from the ignition box to the battery/switch. I've heard of other people having the same issue, This has a 4 pin connector and Horizon are unable to supply without the complete ignition...$900.00 US!
This 4 pin connector has only 2 wires..pos. and neg.... as far as I can tell from pictures. If I can find out which pins they go to I should be able to get this engine running.

Cheers,
Dave.

montt00

Hello all.
Yesterday iI received the Ums 7-77. It's a jewel. But I have a litte question. Some of the pushrods ( 7) are loose. Is this normal, or must I adjust the valves before break-in so that the pushrod are more tight?
Regards,Timo

TimD.

My Feedback: (207)

Should be in running condition when arrived. The pushrods have a tiny amount of movement, gap at rocker arm to valve if I remember correct it is .004. Check them after a couple hours of run time.

Maxam

My Feedback: (62)

Turn the shaft and you will see different ones are loose!!!

montt00

Hello
I donīt understand. Many pushrods are loose. Even when the inlet and outlet valves are closed, the pushrods have much play 0,4 to 0,7 mm. I have seen in an earlier thread that there was another guy with the same lack.
Is it a good idea when I adjust the valves before the first break-in? I like to hear your comment.
Regards,Timo

the pope

I DONT have this engine so take this advice with a grain of salt but if the gaps are wrong there wrong and should be adjusted . It just comes with the territory of owning one and is not difficult to do . Most of my saitos were wrong ( none of my OS's ) out of the box . What gap do the instructions say ? Im very jealus of you guys and that Waco looks fantastic . Cheers the pope

Maxam

My Feedback: (62)

Mont, somebody messed up. YES! Adjust the valves. Look on page one or two way back in this thread for an in depth instruction on adjusting the valves. -Tom