Hello everyone I just got my first evolution gasser in the other day and i was wondering if the masses out there had the same reaction i did when i saw the engine for the first time.

My knee jerk reaction was along the lines of what are they trying to do here. The choke is on a spring which doesnt stay closed, hmm so i called Horizon and asked them what is the deal with their choke set up. The answer i got is the choke should stay closed for starting purposes and as soon as you advance the throttle it will open via the spring. I informed the Tech Rep that the choke on my engine isnt staying closed, and he gave me the same ole story about send it back and they will fix etc etc. Well I told my friends about the spring on the choke and what horizon's plans where with that and starting the engine. When they finaly got thier engines in they had the same issue the choke wont stay closed! So either we recieved 3 faulty engines or the people at horizon are either A. lying to us about their product. or B. Dont know what there talking about.

My question to the masses out there is how did you over come the Choke spring issue ie keeping the choke closed for starting the engine. And what did you do about the throttle did you bend wire around the engine to get at the throttle or did you reinvent the evolution 26gt by adding some kind of attachment to the throttle arm on the engine.

In my opinion and I havent run the engine yet, but just upon looking at the engine i dont think Horizon or whomever designed the engine did a very good job at all.

Thanks

Matt Landers

Walbro has a couple of different setups -really intended for the weed whackin market
One version has a detent and a spring --
the idea is that you set the choke -to closed -- this engages the detent and the throttle is just off an idle -
when you yank the rope and the engine starts - you hit the throttle trigger - which releases the detent -- allowing the choke to snap open.
the engine then runs -
at least that is the design theory.

My own setup:
remove the detent and reset the spring tension (reduce it) - by letting the tang on the spring unwind 1/2 turn
Now place thumb over choke plate or put a twist lever on the choke and close -hold closed with throttle very slightly open .
flippety flip until engine burps - let go the choke and it runs
OR leave ignition OFF - open throttle somewhat
choke till thumb is wet - release choke - close throttle- add ignition (stay out of prop arc!!!) then flip to start.

Seems to me that is more complicated then the way i start my BME 50, and evolution claims that they ease the starting methode with this design.

Hmm go though what you detailed or the BME way close the choke flip 5 tymes, turn on flip till burp open choke and fly...

Off of the topic i saw your post using the 26gt with the F90 did you have to cut the firewall back to get the cowl to line up with the thrust plate/washer???I sent you a PM dick with that question stated..


Thanks

Matt

nope - just put it on the plastic mounts - I don't remember making offsets -
on my engine - I just push choke closed - turn on ignition flip madly as fast as I can and it starts -I release choke and it is running- takes about 5 seconds (from 50 years of startin old glow two strokes)
-I do NOT recommend this as a sequence for anyone else - It is just the way I do it.

HA thats funny. Ya after 3 years i gave up on glow as much as i could. Im gonna have to take another look then because i was orginally gonna put a saito 150 and it was too long the gasser i measured and it looked like it was about the same length.. The only idea me and my friends could come up with is put a nyrod on the choke and have someone hold it closed while you primed, which sucks because you then need 2 plp to fly..

Or don't fuss with the choke at all.

Place your thumb or palm over the carb opening, flip the prop until your thumb or palm is wet, turn on the ignition and start the engine. It really isn't a big deal.

My Quadra Q35s didn't have choke plates and they started very easily this way. Choke plates and choke servos are for sissies. <G>


Ed Cregger

Take the spring off the choke and put a nyrod on a servo to operate it. U will b glad u did.. I start mine everyday this way. Just put a servo arm with a screw in the hole to make it long and put a ball link in it for the nyrod and ball link to hook onto. I close it with a variable switch so it closes as much as i want. When i flip it it fires uup. I might b a sissy to some people but my Evo 26 starts the first time every time lol ..Take the time to do it and u will b glad u did.

the servo setup with a mini servo is good setup- all of myZDZ's have this
the little evolution -is easy for me to "thumb it" cause I mount the engines to allow carb access

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Notice the <G>.

I was just kidding, Dick - oh Creator of the Tiporare and baddest ass/best flying pattern ship of all time...


Ed Cregger

Here is my biggest problem with a choke servo...Im gonna put 2 of these in a VQ P-61 and i want to keep as much of the cowl intacted...Im already gonna be 13 servos deep with this aircraft adding 2 more even micro ones grr its just grief is all...What i dont want to happen is have one the the chokes close on me in flight big time nightmare. Thats why im partial to the open/closed no servo no spring needed method of the BME DA's etc...

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Just out of curiosity, what size flight pack batteries and how many of them are you going to use?

I can understand your concern for reliability and trying to reduce the number of servos as possible failure points. I doubt that the servos would malfunction electronically in a PCM/SS environment frequently enough to be a serious cause for concern.

I've owned several BME 44's and one BME 50, but for the life of me I cannot visualize what you are talking about in favor of such set ups.


Ed Cregger

Im gonna run 4 battery pack 2 for the enignes which is another issue ive read that you need 6.4 minimum and if your pack drops beneath that then the engine doenst run, tell me that isnt the case. If it is Im gonna use the 7 cell 1200mah i believe its 8.4v packs, for ignition, and the standard 2700mah 6v for servos etc...

What im talking about with the BME's i have one on my H9 1.50 size Jug and the choke is either A. fully closed with an loud click and you can also feel it close. B. Just the reverse an audible click and you can feel it open fully...I know its just an opinion but its more reasuring to me when there are 2 postions, Open/Closed. And the throttle arm is tucked up at a weird angle like the evolution. Thats my biggest grip, the choke i can work with to me just doesnt make much sense to design a throttle arm like that

Is it that hard to set up the throttle?
I must miss something

I had a MVVS 26cc ( same thing ) it took me all of 30 mins. to gear up a throttle - I did something similiar to Pe's except I put a short rod from the carb to the clevis in order to make the throttle rod a bit straighter from the servo and for the choke I just fastened a 4/40 rod on it with a ball link and let it hang below cowl ( left spring intacked ). In order to prime I pushed up on the arm closing the choke, turn the prop about 10 turns while holding choke closed, open choke, turned on ignition and within 2 flips it was going. It was actually one of the easiest gas engines that I ever started.

Choke rod is at about 7 o'clock in the pic.

No problem Ed lol thought it was funny myself thats y i said that. The way i have mine set up on a servo makes life sooooooo much easier. Just turn the switch flip the prop and i am off. Actually takes a lot of the fun out of running that engine u never have to do anything to it. Sorta like starting ur car.

Some don't realize that the length of the arm decreases sensitivity of throttle movement - It reduces SLOP ERROR
I see guys putting ball links in existing holes then running control rod at some weird angle and the the entire result is less than satisfactory-- the accumlative wobble and bending in control rod can ruin the smooth throttle response.

On mine i just loosened the set screw twisted the carb and re tightened it. The linkage for the choke and throttle are a straight shot now with no weird angle to deal with. I also mounted a Hitec adjustable servo horn on the throttle and added a choke servo. Makes starting and set up EASY!
Pat

Here's another solution:
http://www.prme.nl/forum/viewtopic.php?t=97
The pring can be removed if the arm butts up well against the carb body. Or it can be fitted on the opposite side.
The brass lever can be bent and twisted to suit the application.
I like to have the spring in place, and apply a pull force when opening the throttle. Absolutely slop-free operation. The servo is set up to have a larger throw for the second half to full throttle whilst never touching the full open stop, and a reduced throw for idle to half throttle. That makes the engine response more linear.