j301

My Feedback: (12)

So the good news it the red locktite held, the bad news is this mod wont work in this motor as it points the tap right into the prop. (I used the cover from another carb I had so I didnt notice until I went to swap it out). So this one will live in my G 20 thats in a 60 size yak. Before anyone goes boring any holes, I will need to try this like the one here: http://www3.towerhobbies.com/cgi-bin...?&I=LXTT83&P=7

j301

My Feedback: (12)

The saga continues, I swear this motor is all but sending me a post card saying "I So Don't Want To Be Used! Get A CLUE!"

To explain; new muffler comes in, take it to the shop to (1) see if I wand to try to side mount it = not really, it would stick out the cowl too much { reason # 1 for buying NGH-can be converted to rear exhaust } and (#2) see if it will clear the Great Planes 180 size motor mount I have already set up to use { NHG reason to buy #2-can be rail mounted }

So turns out I would have to modify (grind away material) from the mount to clear the muffler see pic #1. I don't particularly have a warm and fuzzy feeling about removing material from the part that holds the power [:-], so I think to myself "how about looking into the oddball tripod stand-off deal, muffler should clear that, shouldn't take too much to re-do the mount setup to stand off style [&:]." (this is where the post card came in the mail! [:'(] )

Now I know the vendors of these things have descent intentions, and I cannot hold them to a standard of knowing how their product will interact with 3rd party parts (but they SHOULD be well aware of their own 2nd party stuff!), but when I assembled things to take a look at how rear exhaust/standoff would work, well, see Pic #2. [>:] I am trying really hard to stay positive about using this motor, but it wants to fight everything I need to do! I am going to email Jim at Agape to see what he thinks, or at least let him know he will have to publish something on his site explaining the limitations of his new muffler! I'm not angry "at a $25 muffler," I'm angry at all the time this is eating up! (like now I have to order a stupid 4mm x 0.7 tap for the 90 degree pressure fitting as its not 8-32 like the other 5 I bought! [:@])

I do have one more rail motor mount I think I can make work, but it was the one that came with the plane and definitly not as good as the GP mount.
One step up, two steps back....

****OK, SO NOW RCU IS ON THE BANDWAGON! WONT LET ME POST PICS!! AAAARRRRGGGGGHHHH !!!! So I will pseudo-mime them====

( Pic #1) "Oh, Its hits the mount!!
( Pic #2) "Ooohhhh, Its hits the Friggen mount!! (that's all the drama I could type...)

mchandrayan

My muffler is ready to ship as soon as I pay. I intend to mount it on an inverted engine on the rear, If that would not work them many consider converting the engine back to side exhaust and live with it.
Will let you all know how it goes.
Meanwhile I managed to get a spare OEM muffler from my local dealer who had one lying. Have put that back on the engine and flew the model. let's see how long does this one lasts.

j301

My Feedback: (12)

Jim got back with me, he is aware now of the mount situation and offered both assistance in figuring out a fix and/or a refund, so customer service at Agape is still good. As for my fix, I was able to mod two different mounts to accommodate the muffler with what I feel is a safe amount of material removal (wouldn't go ANY farther though!), but I don't think I would mod the stand off ring, don't really like that idea since Im a bit sceptical of that mount when its 100% let alone modded. I'll throw on some pics when I get is all situated.

j301

My Feedback: (12)

Here is the new nipple installed, making some headway now, waiting for the next gremlin to pop its ugly head out!

mchandrayan

Have you turned the carb around 180 degrees? The next gremlin is then sure to pop up from here.
The carb spigot has a groove that matches with a corresponding groove on the carb base and if it is turned around 180 degrees then you are sure to face issues. Have you tried to test run the engine after modding the carb,

j301

My Feedback: (12)

I haven't touched the carb other then taking off the one cover to add the nipple. Is your facing a different way?

j301

My Feedback: (12)

I see what you mean now, went back through the posts and indeed my carb is backwards! What the heck man, thats how I had it in the other plane too! I pulled the carb and see what you mean about the pulse ports, but the gasket, which is ever stuck to the carb, is aligned with the port so that wouldn't stop the pulse from reaching the diaphragm, but I have no idea how it might affect performance. So now that i have bought every damn nipple in two states, of course it aint gonna fit with that plate facing the head. [:@] You see!!!! As soon as I said "what shark?" da-dum...da - da -da-dum, dum DUM dum DUM dum DUM...............................DA DA DUUUMMMMMMM!!! [X(]

mchandrayan

The gasket should have hole which aligns with the circular hole on carb mount and also the base of carb itself. The milled slot on the spigot head gets completely covered with the gasket except for the circular hole. And then all the three circular holes are aligned. Try prying off the gasket gently off with a hobby knife blade. Without damaging. And then realign if required.
Also I think the issue you were facing with the carb may not have arisen if the carb was oriented right way. That way the side is not facing the oncoming air stream

j301

My Feedback: (12)

Thanks, ya I thought about that after my last post. Pretty much prop wash just blasting away right at the plate would cause that diaphragm to likely just sit there compressed. I have another gasket so if this one doesn't come off, well its spare to the rescue. I will take a look at the nipple thing again once I have the carb oriented the correct way. I still would like to see if I could make that work just to eliminate what may or may not be a problem, if not, well then she goes as is. I have decided to research some baffling techniques to get cooling air to the new muffler. Guess I will call all this effort 'shark hunting' from now on!

mchandrayan

Happy shark hunting

j301

My Feedback: (12)

OK, so I started to think NGH stood for "Not Gonna Happen" but I think I got this one little chunk sorted out. (ignore the servo arm on the choke, needed that to be able to reach the choke on the P40, it might not be needed on the F4U.)

mchandrayan

J301, Did you run the engine again? Results?
I converted mine back to side exhaust as the piston and ring for the rear exhaust went bust after an overheated run with the cowl on.
The engine ran like a champ with the new ring and original side exhaust piston two Sunday's back, no troubles starting, few flicks with choke on, get the pop, choke off and 2-3 flicks get the engine running. Put in 2 flights with the cowl off for fear of overheated engine. The aircraft did not get flown last Sunday. Yesterday took it to field, and followed the starting procedure. No she would pop but would not fire. Finally borrowed a starter man enough and the engine started. Warmed up for few minutes, idle up and down checked all well! Up she goes in to the air. Few minutes of straight and level flying. Try a roll. Right roll no problems, left one and the engine sputters. Stops by the time the roll is completed. Landed dead stick, no damages except a bit of skewed undercarriage leg and some hurt pride. Never mind we will start it up right away and go up again.
Hand flipping same result, pop but no starts, get the starter out, fires up after some coaxing, idles op, but the moment the throttle is advanced it just quits. Plain and simple. This happened few times. Tried to richen the HSN needle but no avail.
Any ideas what is wrong?

w8ye

My Feedback: (16)

If they pop pop pop but never will actually run, you have a leaking reed valve or big crankcase leak somewhere

j301

My Feedback: (12)

That could be several issues, carb, bad gasket/s, what w8ye said, intermittent ignition or unit on its way out, plug gap/fouled.
Im still working on my 35's new home, so I haven't ran it up again yet, but when doing some more research I found the the 17 was having two issues that were fixed by a "version 2." I don't know if there is a "v2" for the 35, but I emailed Jim at Agape to see if he knows.

Issue 1 is that the carb (and I'm hoping to get Turk's attention here) is sitting only on a gasket and leading to heat transfer to the carb causing vapor lock, etc, and if you look back in this thread you can see Turk's motor has a different looking gasket/flange then just my gasket. (post #42)

Also, the position of the carb (17 just like the 35) was causing the prop wash over the carb to siphon out the gas, so a velocity stack cured that issue.

I will add the stack to mine, but need to find out if there is a newer spacer for the heat issue. Seems Im finding a lot of little issues that could have lead to the last failure, either alone or when added up. I'm wanting to fix as much as I can but the issue will be I wont know which "one thing" was the fix, but as long as it stays running it will be worth it.
When I get to the engine run point I will see if I notice any thing that might be helpful in your situation, and if you find something please let us know! I also think I might try a Bowman ring at some point, but not yet.

j301

My Feedback: (12)

This is the response I got back from Agape today. I must say the service there has been above par, especially in our hobby! I told him to charge me for at least the stack and shipping since I was going to order it any way. We will see how it goes, the only concern is how far "up and out" the stack will be, the carb is pretty close to the prop as it is.

"Jim:

The 17 is pretty sensitive to heat transfer to the carb from the crankcase. It also benefits from the addition of the velocity stack. The 25 and 35 do not seem to be so sensitive but it does not hurt anything to add them. In a perfect world all 2 stroke gas model engines should use a velocity stack to improve the air flow into the carb.

I have the PTFE carb spacer and would be happy to send you one, the required gaskets, and longer screws. I can also send you a plastic velocity stack. All no charge if you send me your shipping address.

I would make sure to check the engine for ingested dirt and verify crank did not get bent if it was in a crash.

Jim


Jim Willis - Owner
Ben Willis - Manager
Agape Racing and Hobby, LLC"

Turk1

Hi Jim,an insulator between carb and hot body is a must for gasoline engines to prevent vapor lock.Yes At beginning NGH didnt have an insulator on small CC engines I notice.
Also wrote to Mr.Chow about it .Then I see all engines include insulators with it.I think yours either an early production or a defective installation from China.
To Mr Chandrayan; I would try to diagnose what is the problem with engine.So pls. try to put some fuel into carb before cranking it.Will it start immediately or still hesitating?
Then I would follow the fuel feed via hosing to carb.Is fuel pumping to carb from tank regularly while engine running different throttles?
Can it be from clunk system /tank?Also check the gaskets as mentioned.(I dont think backplate gasket has problem)
If you can, remove the pump side of carb cover and check,clean the valve system/diaphragm of it.Check the carb fixing screws also.You should open a little bit of LSN instead of HSN. to have a good transition.
Hi Jim,This engine is rotary valve,front carb ,glow type engine.No reeds,only backplate and cylinder gaskets.

j301

My Feedback: (12)

Thanks Turk, I figured you would be watching! Ya, I bought mine early on as it was the only beam mount I could find at the time. Will likely let new motors sit on the market for a while next time to get some of the bugs worked out, I guess you can say I did my part on "early exploration" on this one! Still crossing my fingers.

mchandrayan

Thanks all for pitching in to help.
The issues are not what every one (mostly) is trying to help with. The issues are mainly two.
1. Two Sunday's back the engine would easily start by hand and ran nice on ground and in air. After a gap of one week, the engine did not want to start by hand (would pop but not start) unless persuaded by a 12V starter. Once started it did run well for few minutes and stopped in mid air.

2. Second issue was that after the dead stick the engine would run only on low throttle and quit the moment throttle was advanced.

From the time the engine ran well till the gremlins surfaced there was no change in anything. Post I experience the issue I have checked the carb, tank, lines, clunk, tank (all clean).
There is no problem in suction as when choked and filliped I can draw fuel from tank to carb. The engine does not show any sign of leakage from back plate or cylinder head. Even the carb gaskets when opened up were dry so I think there is no leak there. The engine when it run does spit out raw fuel (I think velocity stack is the answer for this).
I think I will try to richen the LSN and see this Sunday. I am also planning to check the engine with another ignition, plan is to mount the engine back on my test bench and see what it does.
And oh my engine has the carb insulator from the factory.

j301

My Feedback: (12)

I would consider getting a rebuild kit for the carb and clean out everything with carb cleaner and compressed air. Could be a chunk of junk down in any one of the ports/passages. Also check the pulse ports on the block. Trying a different ignition is a good idea, also check to see if the fuel tank is bubbling or there is excessive air in the line when its running. These gremlins can be a pita!

mchandrayan

Yes, I have a spare WT 664 carb (if I remember the number right) that I would be taking along and try running the engine with that as well if the other ignition also displays same issue.
I have also been thinking on the lines of debris in the carb, as the engine is mounted inverted and carb is facing down, the field is kind of dusty/gravelly and it is possible that while running the engine with cowl off some debris may have been ingested. But I am also curious as to if this was the case, it should have been trapped on the fine wire mesh bowl inside the carb and that was clear when I opened up the carb end with one big screw. I did open the other side to lift of the membrane but did not find any debris that side and did not want to meddle with things I saw inside :-)

mchandrayan

Update, the engine ran like it never had any issues at all.
I had the same original carb which was put back (after checking for debris), had taken along another carb and ignition to try on the engine.
Started the engine, and it did start with hand, throttled up and it did. Wow!!!
Anyway since the needle was messed up from last time, had to retune and the engine ran like a champ.
Verdict - Whatever was causing the problem was cured when the carb was opened and reassembled

Also tried the new muffler from Jim at Agape. I had my concerns due to apparently smaller volume of the muffler, but it worked like a charm. No needle adjustment was needed. I am glad I picked up this muffler

bcchi

So what/ many planes need extra nose weight anyway.Good place to add wight that does no show.
BCCHI

Heli-NuBee

I just purchased an NGH 35 CC rear exhaust two-stroke engine. I see that this forum has been pretty quiet for the last year. I hope that means folks are pretty happy with their engines.

Best wishes and good safe flying.

Heli-NuBee (AKA Roger the radial rabbit)

j301

My Feedback: (12)

Hey Heli, seems like we follow each other around on these boards lately! I have mine in an ESM 80" Val. The motor itself is heavy for a 35, but the val needed nose wt anyway (another lb with the NGH!). The plane ended up being the heaviest I own, but the 35 pulls it through the sky with room to spare; much faster than scale (just like I like it). I was surprised at the power it makes, and am happy with mine. Maybe not a 3d motor, but perfect for warbirds and other scale models.