Norvel 061

I started my Norvel 061 for the first time this afternoon and, while it seems willing, it will not run.

The setup is just a piece of board with the motor bolted to it and A standard Sullivan 2 oz slant front plastic tank. This setup ran perfectly for my OS 10 but the Norvel will not draw fuel. I do not have the muffler fitted so there is no muffler pressure but it runs happily from a prime through the venturi or a pressure blow into the tank but once the prime runs out, it will not draw fuel.

I heeded Currell's advice and used the starter spring but there were times when it would fire and run a few turns from a flick of the finger and if there was enough fuel around, it would run for 10 or so seconds from the finger flick.

This technology is totally new to me and it is the first time in my life that I have used a starter spring and, so, I have cuts on both hands to prove that I did not know what I was doing.

Is there any mechanical issue that I should check on this new engine to find why it will not draw fuel. I cannot get it to draw fuel when I put a thumb across the venturi but it runs for some seconds every time I prime through the venturi or force some fuel into it by pressurising the tank. The motor wants to run but can/will not. Are these little beasties susceptible to tank variations?

Any suggestions will be much appreciated.

Cheers, Geoff

Geoff,
I'll give it a shot. Really make sure that you have no air bleeding into the fuel line. What you might want to try also is opening up the NV more, even to the point of 2 turns. It would help to run that puppy on muffler pressure. Hopefully there will be some others that will post that can help more. Just hope this gets you in the right direction. Steve D.

LAST EDITED ON Aug-11-02 AT 08:47 AM (CDT)

Geoff,
Using your present setup, open the needle valve until it draws fuel when choked.
It that does not work, remove the tank fuel tubing and the needle valve from the spraybar. Look into the spraybar for any obstructions. If there are any, clean them out. Use a fresh piece of tubing and connect one end to the engine and blow into the tubing while plugging the other end of the spraybar with your finger. If air passes through, fine. If not, you must disassemble the spraybar and venturi to see what's blocking the flow path.
Check that the needle is tapered up to about 3/16" from the aluminum screw-in part. If the untapered part is much more than 3/16", you may not have enough range to open the needle. If this is the case, you need to seek a replacement or regrind the needle. To check this, reinstall the needle valve fully closed and open the needle to the point that air passes through.
Good luck,
George
Revision: After rereading your post, I noticed that you can get fuel through when using pressure. Are you setting up the needle with what works or by factory recommendations? Many guys try to set it up as the factory suggests, not realizing that manufacturing specs can cause the adjustments to vary. Use what works.

It sounds like the engine is just running out its prime and that you haven't got the needle valve open enough for a decent draw from the fuel tank. I've had similar experiences with PAW diesels when trying to start them at the manufacturers recommended needle valve sttings only to find that the engine was not getting enoug fuel to sustain running. Running off the prime raises many false hopes and causes many false starts. Open up the needle valve a 1/2 turn at a time until you get a sustained run then fiddle to your hearts content.

I have yet to start up my Norvel 061 as I am going to use it on a FF ducted fan plane from the 60's and I intend to run it in with the fan attached which makes the use of a spring difficult.

There's also some notes on breaking in a Norvel engine on the Norvel web site http://www.norvel.com/til.adp

TTFn

Open the needle valve until you draw fuel. Sounds obvious doesn't it. But at Brodaks fly in this fummer there I was, in the OTS circle, flipping the prop, burning out prime and the engine would not start. Now this was a broken in Fox .35 that always started for me. After declaring an attempt and back in the pits, I "discovered" my needle valve was closed all the way, it just looked open. Needles to say my face was as red as the trim on the wings. Some times the obvious is just not obvious. I love this hobby.

Thanks guys

I tried all sorts of needle settings from 1 1/2 turns up and actually had the NV screwed out so far that is was off the thread at one stage--just held in by the spring.

I get fuel through when I put a squeeze bottle on the tank inlet and cover the vent with a finger and the little thing runs until it uses up that fuel.

I will check the NVA completely and then change to a 1oz round tank on the stand.

I wonder whether the way the feed tube sticks up from the front of the slant tank--above the engine in this case--might be a factor?

Thanks again, Geoff

You may have the AME version of the 061 which prefers pressure feed.

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Quoted from Great Hobby site product descriptions:

The AME .061 is a world renown competition engine and the perfect choice for all types of high performance 1/2a flying. They feature a large venturi for optimum air intake, so back plate or bladder pressure and a perfect fuel tank setup is required.

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Quoted from Norvel site:

Q The AME and BigMig .049-.061 engines look exactly the same. What makes the AME more powerful?

A The fuel ports inside the cylinder of the AME are three large ports, allowing for greater flow of fuel to the combustion chamber. The BigMig uses five small ports, which give a little more suction for easier starting, but take a little off of top end rpm.

Also, the AME has a tighter cylinder/piston fit so it will have higher compression and more power. But, it takes longer to break-in.

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Hope this helps.

Geoff: it is just not broken in yet. Keep trying. Does it have any instructions re lapping it in? I understand that Norvel has been sticking this in with the instructions. Something like taking the head off, and turning it over a couple of hundred times. Currell

That it may be an AME rather than a BigMig makes a lot of sense!

With regard to breaking (Big Mig), you probably want at least 3 copper head shims during this process. If it runs a prime tho', I think it is already past the intitial 1->2 tank breakin where it is darn hard to get the engine to run. By the third tank (~<1 oz tanks) it should be broken in well enough to be easy to start with the spring.

Even if it is a BigMig, more shim may help. Currell