Nemett Lynx 15 cc 4 Stroke I/C Petrol Engine

[Jasonb]

Yes magnet has to face the right way round, about 1/32" gap

 

[Cogsy]

On my Chinese copy, the magnet definitely has to face the right way, but the gap can be anywhere from almost touching to 4-5mm away and it will still spark.

 

[Swifty]

As the others have said, the magnet has to have the correct pole facing towards the sensor. If you check my Lynx build, I did mention a method of finding out which is the North or South pole of the magnet. I'm not at home at the moment, so have limited internet access, otherwise I would look it up for you.

Paul.

 

[Cogsy]

The easiest way I know of to determine the correct poles of a magnet is to use a compass. Hold the magnet near it and see which end the North pointer points at. That should be North pole of the magnet if I remember correctly.

All I do for hall sensors is randomly choose a pole of the magnet and wave it over the sensor. If it doesn't spark I reverse it.

 

[gus]

Ok. Got it. Will get Sparks going. The CDL is new trick for ''old dog'' used to Contact points and HT Coil..

I have another backup set bought for the Webster and Rupnow H&M for 10mm plug.

Will go all out today. Compression was very good. Very hopeful will make a few pops today.

 

[gus]

OK . Got the sparks but Timing Disc and housing not suitable. Will cut and clone Paul's .

Meanwhile will hunt for suitable magnets.

 

[gus]

Cannibalised 4mm magnet from Magnetic Pickup Socket Spanner. Getting very good sparks.

Fuel delivery from not ideal low level fuel tank stabilised with check valve.

Engine just won't start. Not even popping. :wall:

 

[Cogsy]

Hmmm, if you have good spark, good (enough) compression and fuel then it 'should' fire. If you've fiddled with the carb needle enough and it still won't do anything then I'd try the ignition timing. I'd try altering it in one direction and keep altering it until it either begins to fire or you've changed it so much you can rule it out as the cause.

I'm sure you'll get it Gus. If it was easy it wouldn't be fun!

 

[gus]

Hmmm, if you have good spark, good (enough) compression and fuel then it 'should' fire. If you've fiddled with the carb needle enough and it still won't do anything then I'd try the ignition timing. I'd try altering it in one direction and keep altering it until it either begins to fire or you've changed it so much you can rule it out as the cause.

I'm sure you'll get it Gus. If it was easy it wouldn't be fun!

Thanks. Cogsy.

I thought the Rupnow H&M Engine was tough.Took quite a long while getting the Hitting and Missing to happen. Almost gave up.
Will be fun and surprising when I get to the cause. Taking a break now.

 

[Nicolas]

Hello Gus,

I just had a look through your build so far.

Great work so far, keep it up

 

[gus]

Hello Gus,

I just had a look through your build so far.

Great work so far, keep it up

Hi Nicolas,

DIY I.C. Engines has a very bad habit of not starting at the very first few sessions. Hopefully it will pop a few times and from there run a few seconds.
Getting the valve timing right and ignition timing is first step. Tuning the fuel jet quite tricky.I am jinxed, all my three engines happened this way.:wall:

Part of learning curve. Having fun just trying to get engine started and running and vroom vrooooommmm.

 

[gus]

OK. Done all trouble shooting. Valve timing not correct. At the crack of dawn will run engine.

 

[gus]

Good News,

I got a few pops and ran for 5 secs. Means I am getting near. Battery about flat.Now recharging and let starter cooled down a wee bit. I did burnt a starter with the GrassHopper Engine last year.

 

[Cogsy]

Good to hear Gus. It won't be long now. Remember to do a video once you get it going.

 

[gus]

At long last after the few pops,and some fine tuning advancing/retarding ignition ,got her running non-stop till shutdown after 22 secs.The pops did cheer me up. Please visit my FaceBook Post under Augustine Teng.
There are two videos,the first w/o silencer and the second with.
I need help to post a good video on YouTube and then to this forum when engine is tidied up.
Will spent the next two months running this engine before heading for other projects.
HMEM Folks. Thank you much for giving Gus your timely expert advice,support and encouragement to finish up and run this wonderful unforgiving engine. I did get sleepness nights and near burnt-outs.

 

[Brian40]

Well done gus another remarkable achievement.

Brian.

 

[gunna]

Congratulations, Gus. A great looking engine.

Ian.

 

[Jasonb]

Weld done Gus, good to know its a runner

 

[Cogsy]

Congrats Gus. It runs really nicely and responds well to the throttle already. Nice work!

 

[Brian Rupnow]

I knew you would get there Gus.--Congratulations.---Brian