Partial Rebuild

25.01.11: While waiting for the new con rod bolts to arrive I thought I may as well build up the top end and figure out a new throttle set up as the gx390 carburettor throttle butterfly turns the opposite way to the gx200 butterfly. The video explains in more detail.

Eggmotor set back

24.01.11: In a recent post I mentioned about the improvements I’m wanting to carry out on the little Eggmotor. Well, firstly an update on the blown gasket problem. I think the reason the gasket could have blown is that when I fitted the 18cc GX160 cylinder head on the first time I built up the engine and then also when I swapped to a 14cc head, is that I used ‘thread-lock’ on both occasions and I think this has caused incorrect head bolt torque results. I don’t think re-applying the liquid over caked on thread-lock from a previous time is a good idea. Watching some of ARC Racing’s tutorial videos on the ustream.tv web site I’ve seen that they apply motor oil to all bolt threads to prevent corrosion and to aid correctly torquing the bolts. I suspect the gasket blew due to lack of bolt pressure. I have now in preparation for the new parts re-tapped(cleaned) the block threads and bolts and I can now easily screw the bolts into the block by hand.

'Cleaning' out the threads

Hand tightened with ease

Also, while using for the first time a new torque wrench with the correct sized drive head (so I don’t need an adaptor which would make getting inside the block impossible) for a borrowed 1/4″ 12pt socket for the billet con-rod I accidentally overtightened the bolts to the point where one of them snapped. The torque wrench was ‘clicking’ as it should while gradually pre-loading the bolts but when I got to the 120in/lb setting there was no ‘click’ and so stupidly I slowly continued to tightened. I’ve ordered a new set of bolts from AGK and currently waiting patiently for them to arrive.

Snapped ARC billet con-rod bolt

Monster no more

24.01.11: It is with much sadness that I have now sold the GX420 Eggmonster engine. I have been told by it’s new owner that it will have a rich and fulfilling life bolted to a kart and blasting along at high speed. I have kept hold of the frame, quad unit and propellers in case circumstances change in the future and I decide to employ a 4 stroke trike/quad PPG unit for my aviation needs.

Bare Monster Frame

Goodbye Monster Engine

Goodbye Monster Engine

Blown Gasket

11.01.10: In preparation for fitting the upgrade parts (ported & milled 14cc head and gx390 carb) I found upon removing the cylinder head that the gasket seal had failed. Not sure how long it’s been like this and possible oil leak into combustion chamber too as there’s a greasy, sooty (been running rich) residue inside the head chamber and on the valves as the failure section is very close to the oil channel. That could be normal though for running rich but I’m no expert.

Chronicles Of Egg

03.01.11: Now that YouTube seemed to have upgraded me to have videos over 15 minutes in length and as the ‘Chronicles Of Egg’ DVD is becoming a little out of date now, I decided to upload it for public viewing. The video was produced towards the end on 2009.

Even More Power

02.01.11: As you can see in the previous post, the little gx200 powered Eggmotor is looking quite the part. Since then I was concentrating on the Eggmonster project again but now I have returned. I’m not getting any younger and my back isn’t what it use to be and so I’m wanting a good 10-15% increase in power/thrust to be able to fully exploit the little Egg.

With this in mind I have ordered a flat-top piston and billet con-rod. A friend has custom made me an alloy GX390 carb adaptor manifold so the engine can breathe much better compared to the asthmatic stock carb and also given me a milled and ported 14cc cylinder head. Compression will be raised from 10.3:1 to around 15:1 and so super-unleaded fuel will be a necessity from now on. My rough calculations come to an extra +2hp and thrust output up from 40kg(88lb) to around 47kg(104lb).

Hi-compression head, custom manifold and GX390 carb.

To view the port matching work I’ve done to this cylinder head and manifold adaptor then check out the photos on our Eggmotor forum.