Billsky

My Feedback: (37)

Well, tried the engine with the new muffler yesterday and could not get it to run reliable without the glow plug igniter left on. Switched to the stock muffler and the same issue. The engine ran great last year prior to being stored for the winter. I ordered the suggested long needle valve to see if that helps get it running reliable again. Can someone please post what the stock setting should be for the High/Low speed needles?

earlwb

It may be that the glow plug coil element is contaminated with something. I would suggest trying a new plug. You did use fresh gasoline mix too, didn't you. The modern gasolines tend to age faster than in the past and can become quite poor for using in a engine. At first the octane rating rises as the more volatile chemicals evaporate out and other chemicals change composition over time. Then then gasoline just gets to where it won't ignite anymore.

AndyW

My Feedback: (1)

I agree about stale gas. Every spring, I get out my lawnmower and the %$#*&* thing wont start. Then I remember,,, I left some gas in the tank when I put it away. Adding fresh gas to stale,, not a good idea.

Not saying that this IS the problem, but something to consider. When I say fresh gas, I mean freshly mixed. I remember to use up the last bit in my fuel can, but always forget what's left in the tank of the mower. As we get as low as 40 below in the winter, and the gas in the mower is subject to heating and cooling cycles,,, well,,

Also, I've found that some brands of gas sometimes DOES make a difference. Aslo, go to a BUSY service station.

earlwb

Yes stale gas may not be the issue. But I know some guys mix up a fresh batch of fuel every time they go to fly a airplane or helicopter.

I mentuon ion the glow plug failing because the first time I test ran my engine the glow plug worked for the first tank of fuel and quit after that. But the second plug has worked for a long time now.

hllywdb

I would go for fresh gas over the plug. The plugs seem to be good/bad and not much in between. Might have some crud in the needle area too if it set all winter with some fuel in it.

hllywdb

I would go for fresh gas over the plug. The plugs seem to be good/bad and not much in between. Might have some crud in the needle area too if it set all winter with some fuel in it.

Billsky

My Feedback: (37)

I did mix up a fresh mixture prior to firing it up. I also have another gx that worked with no issues on the same gas. Not sure what it could be, rinsed the engine with denatured alcohol and have left it set, If I continue to have the same issue will try the carb from the good running gx to see if the carb may be the problem. Also put in a new P3 plug with the same results. I did remove the head to take a peek and did not see any other gasket besides a copper one. Seems to show a different gasket required in the manual unless I am reading it wrong. part #5 on the engine parts list. Is there suppose to be two different type of gaskets? If so, that could be the problem.

Charley

My Feedback: (2)

Hi Bill,

After I bent the rod in mine, it wouldn't run when the glow battery was removed. You might want to check that the top of the piston is even with the bottom of the exhaust port at the bottom of the stroke.

CR

Billsky

My Feedback: (37)

Charley, thanks for the tip. I took off the cover plate and the rod was bent shaped like a banana. Mystery solved. I would not have thought to check the connecting rod. Appreciate the help.

Charley

My Feedback: (2)

Glad I could help.

That rod is a casting; you can see the mold lines on it. It's a cheap part. When I ordered mine I got the gaskets for the top & bottom of the cylinder & a pair of wrist pin keepers. Glad I got the keepers. The ear breaks off those keepers readily!

The NV guys take Paypal & they ship quickly once they have the payment in hand.

CR

aspeed

They must use real soft aluminum in the rods. I guess it is better to bend a rod than break it. My .074 got twisted real easily too. I just bent it back. I haven't seen a Norvel rod lately, but it sure looks like it would be easier to make a rod shaped like that on a lathe/screw machine, rather than a casting. As far as the ears are concerned, some guys clip a bit of the e clip of so it doesn't vibrate so much and snap off.

Billsky

My Feedback: (37)

Is there a particular way you have to install the new connecting rod and the piston back in the sleeve? As always I forgot to take a photo prior to removing the removing the parts. Will be ordering the new parts tomorrow.

Charley

My Feedback: (2)

If you haven't separated the rod & piston you'll be all right, since you remember which way the bend in the rod went. The piston needs to go back in the way it was oriented in the cylinder. It's already worn in y'see. The rod can go in either way. If you have separated the rod & piston, maybe you took out only one wrist pin keeper & remember which one.

Sheesh, man; I didn't take it apart until I had the replacement parts in hand.

CR

Billsky

My Feedback: (37)

As much as I have dealt with this stuff, sometimes I just overlook the basics!!!

Charley

My Feedback: (2)

Yeah, I shouldn't have said anything; it's not like I never made a mistake myself. After all, I bent a rod in a hydraulic lock, eh?

If you put much time on the engine last season you might be able to identify the exhaust side by the stains on the piston. Out of more ideas now.

CR

Billsky

My Feedback: (37)

Got the parts and fired it up. Runs like it should. I do really like the NV engines. Will put much more time on it this year. Installing it back on my Hangar 9 Tribute possibly for a flight this Sunday.
Thanks for all the help

Charley

My Feedback: (2)

That's great! Remember to let us know how that new muffler works out.

BTW, were you aware of this? http://www.modelflying.co.uk/forums/...p?th=68885&p=1

CR

Billsky

My Feedback: (37)

Yes, I will mount the muffler to let you all know if there are any performance issues with the engine. I did know about the weak tribute. I have slapped epoxy in there the help with the problem. Thanks for the reminder. Muffler mounted.

Charley

My Feedback: (2)

May I suggest you put a piece of silicone fuel tubing to the muffler pressure tap? That looks like Tygon & if so, it will melt when the mufler gets hot. I usually put silicone on the muffler tap & switch to the Tygon with a small piece of brass tubing.

CR

earlwb

Yes I suggest a short length of silicon tubing from the muffler fitting to the regular Tygon or K&S clear tubing. About 2 inches long does the trick. The silicon tubing withstands the heat from the hot exhaust gasses right there at the fitting. Tygon, or the clear tubing will promptly melt on you at the muffler fitting.

Billsky

My Feedback: (37)

Tubing has been added, Thanks again for the advice. A lot colder than expected here in PA, will try and get a later flight in today when temp gets into the mid to upper 40's.

Billsky

My Feedback: (37)

Got 1 1/2 hours fly time in today, the Kraft/RJL muffler worked with no issues. Performance was better than the stock muffler. Seemed to have a few more rpms. I did not put a tac on it yet, was too busy flying

Charley

My Feedback: (2)

How's noise level? More, less, about the same? It didn't seem very loud to me with the the stock muffler. Probably because it doesn't have that nitro crack.

CR

Billsky

My Feedback: (37)

The noise level seems to be about the same. I am sure without the baffle it would be very loud. Also have a MDS 40 muffler that fits, will give that a try soon also.

Charley

My Feedback: (2)

Thanks for the reply,

It sure would be a service if you could provide us with some RPM info with the various mufflers on the same prop. Doing the research would provide a reason to buy a tach.

CR