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-   -   Evolution 33GX issue (https://www.rcuniverse.com/forum/gas-engines-142/11668838-evolution-33gx-issue.html)

planenutzz 08-26-2019 03:50 PM

Evolution 33GX issue
 
Hopefully somebody can provide a little guidance.
I have a failry new Evo 33GX gas engine in my little H9 RV-4 and to date it has been running quite well. I followed the break in procedure as per the manual as I had read these engine can be quirky.

Sunday I got one flight and engine was acting as though it was very lean. Landed, let cool and it will start and idel nicely but could not transition past 1/2 throttle, each time it would hesitate and die.
No amount of adjustment to needles changed this. We reset the needed to both being about 1-1/2 turns out but same problem persists.
Perhaps a blockage in the carby or even a crap batch of petrol?
I havent pulled the carby off yet.
thoughts?
cheers
P

BarracudaHockey 08-27-2019 04:00 AM

Ignition battery?

ahicks 08-27-2019 04:23 AM

Low ign. battery is a good idea, but if that checks out, I'd be suspicious of the little screen/crap trap in the carb being partially covered with that mysterious clear crud that just appears out of nowhere. That's where I would head next.

planenutzz 08-27-2019 01:09 PM

Not sure how a low battery pack would cause this. It had a fresh charge and the battery monitor I have in the cockpit showed full green.
I have an inline micro filter, that was quite clogged - see photo. the micro filter in the carby itself was very clogged. Quick soak in acetone and a clean with a small brush sorted them.
I'm quite convinced the last batch of 95 octane I used was dirty, I normally use 98 which lasts better and has less particles in solution.
the 95 will go in the lawn mower and I will mix up a new batch using 98 octane.

Will run it on Saturday and see.

https://cimg9.ibsrv.net/gimg/www.rcu...25161fd405.jpg
https://cimg0.ibsrv.net/gimg/www.rcu...1507f912fa.jpg
.

BarracudaHockey 08-28-2019 03:31 AM

These motors aren't high compression, regular octane is perfect, and if you can get it, ethanol free.

planenutzz 08-28-2019 02:30 PM

Think I have found the cause of my blocked filters. I drained the fuel from my caddy into the can I have for mower fuel and looked into the bottom of the can to see loads of rust!! I use a metal 4L can that originally had Castrol M castor in it.
That can will go in the bin and now I'm looking for anew set up using a nylon fuel can and a new pump.
The old SIG 12V gas pump is on its last legs.

LHS shop, well not so local but in this country has the Brico Fuel can system but they want $359AUD for a 10L can and pump!!!

What other good 12V pumps for petrol / gas are there? I see DA has their version which isn't that cheap either.

Truckracer 08-28-2019 08:46 PM

Unless you’re flying something really large, what is wrong with a hand cranked pump? I’ve used the DuBro and Hanger 9 offerings labeled for use with gas and they last for years. Very reliable and very little to fail.

BarracudaHockey 08-29-2019 03:23 AM

I have a gas and kero setup from RC Fueling Systems that have both been in service about 3 years of regular use.
https://www.rcfuelingsystems.com/

ahicks 08-29-2019 03:39 AM


Originally Posted by Truckracer (Post 12546692)
Unless you’re flying something really large, what is wrong with a hand cranked pump? I’ve used the DuBro and Hanger 9 offerings labeled for use with gas and they last for years. Very reliable and very little to fail.

X2!
A 1 gallon plastic gas can from a discount store, a hand pump, some bulkhead fittings, some fuel line, and you can make your own in half an hour for less than 25-30 bucks. And they last for many years....

planenutzz 09-05-2019 03:24 PM


Originally Posted by Truckracer (Post 12546692)
Unless you’re flying something really large, what is wrong with a hand cranked pump? I’ve used the DuBro and Hanger 9 offerings labeled for use with gas and they last for years. Very reliable and very little to fail.

why would you want to hand crank when you can flick a switch? I have not used a hand crank pump since 1994 and have no intention of using one now.

planenutzz 09-05-2019 03:30 PM


Originally Posted by ahicks (Post 12546720)
X2!
A 1 gallon plastic gas can from a discount store, a hand pump, some bulkhead fittings, some fuel line, and you can make your own in half an hour for less than 25-30 bucks. And they last for many years....

x2 no hand pumps!!!

Truckracer 09-05-2019 08:31 PM

As they say, different strokes for different folks.

planenutzz 09-08-2019 04:54 PM

and as I stated in my question "what 12V fuel pump!! " not hand crank

cymaz 02-06-2022 01:05 AM

I’ve just replaced my 33gx carb ( the old HDA) for a wt1115. Runs very well!

You need to swap over the throttle cable and fuel pipe. The choke lever is on the same side. You also need to file off some of the casting on the diaphragm plate so it doesn’t foul up against the head.


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