Starting the hoglet

[neil_1821]

I have a few questions relating to the starting of the hoglet, hoping someone could offer some advice.

I tried starting my hoglet tonight, for the first time ever, but I kept getting fuel peeing out of the carb with the fuel line plumbed in without anything moving. I'm pretty sure that's not normal but I can't see that there's anything wrong as it was built to the plans and everything is literally to size by a few thousandsth of an inch. The design itself is the 2 Jet throttle by Jerry E Howell.

Secondly, my timing is that it sparks just as it begins it's downward stroke, is that normal?

I got a few pops and bangs/farts from the exhaust but that's all. I'm going to re-check my timing tomorrow, but thought i'd see if anyone had anything else to check.

 

[Mike1]

You may have your fuel tank level too high causing the fuel to syphon, the top of the tank should be level with the jet or below, the engine suction should pull the fuel through the jet. Set the ignition to fire at TDC once it is running you can adjust for best running position.

I don't have Hoglet but the above is how I run my engines.

Mike.

 

[neil_1821]

Thanks for that Mike, I never realised it could syphon if the tank was too high!

I’ll adjust the timing and take it from there

 

[neil_1821]

So I've adjusted my timing so that it sparks at TDC and it seemed to improve but it doesn't seem to me that its drawing much fuel. I'm using the colemans fuel from here: http://www.gooutdoors.co.uk/coleman-liquid-fuel-p175327

It'll pop and bang more so than it did last night but it just won't catch. I'm really struggling for things to check as I've not much knowledge in this area. Can anyone help because i'm about ready to put it in the bin

 

[Mike1]

Don't bin your engine most engine builders have gone through the no start phase, at least the engine is popping and banging, check fuel needle settings which can be critical and maybe try petrol see if that makes any difference.

If you have compression, a timed spark, fuel at the needle jet, you are getting there.

Mike.

 

[neil_1821]

Been playing a bit more with it, took the carb off and started spraying fuel directly into it and it kept popping but it was firing out of the inlet rather than the exhaust, so i've adjusted the valve clearances, which made a huge difference to the amount of suction you could feel.
Put the carb back on and it doesn't really seem to suck up any fuel, although placing your finger over the air inlet would suck the fuel up and then it'd pop and bang. The plugs were wet so I think it's more of a carb issue and fuel not being pulled up. It's hard ot know where to put the needles as there's a high speed needle and an idle needle, got both about 2 turns open, but i'm going to go back at it tomorrow and hopefully get a bit better.

 

[lantain1982]

Hello Nei1821.
I had the same frustration in starting my Hoglet. Its a bit of a learning curve but this is how I get mine to fire up.
My fuel level is in line with the carby. Fuel line exits the tank and loops to the carby. I open the idle needle valve 1/4 turn. High speed valve is closed.
Set throttle to about 1/2 open. Ignition to fire TDC. Place finger over the carby and spin the engine over a few revs with ignition off. I add that I power spin the engine with an adaptor I fitted to the fly wheel. Turn ignition on. Spin the engine over. Keep spinning, engine should pick up and fire, maybe a bit rough.
Adjust idle jet to get a stable run. I have found high speed jet, if open can upset intial running. Hoglet seems to be touchy about fuel settings.
Keep playing about. Pops and bangs are a good sign.
Hope this helps. LANTAIN1982

 

[tornitore45]

I am now at the same point. My Hoglet pops and spits but no sustained running.
The plans give no indication on phasing the cams to the crank. I just tried to set the valves switch over from exhaust to intake at around TDC but is a crude way to do it and can't really tell where that happens with accuracy.
My carburetor is a simple one without idle adjustments. Has 0.24 bore which worked fine on a similar engine.
Suction and compression are good.
Anyone has data on the cam phasing?

 

[lantain1982]

Hello Tornitore45. The following is how I set my Hoglet timing.
I established tdc on the LH cylinder when looking from the front of the engine. Made a mark on the flywheel for reference. Rotate the flywheel 90 degrees. [clockwise] Making sure the flywheel stays put, loosen the tapered screw that locks the gear on the crank is loose, put a dial indicator on the front intake valve lifter. Turn the gear till you find the highest lift point. Lock the tapered screw. Thats it. To set spark timing, set the front piston so it is on the power stroke. Move the timing lever untill you get a spark. This will give you a starting point and the engine should fire?
Once it is running you can rotate it to get the best running condition. [Note, I acknowledge Camm-1 for the above information].
I am using a twin jet carby. For starting I stick my finger over the intake and apply a power starter. I cannot start using the kick starter due to compression. Hope this of help.
Cheers, Bill.

 

[tornitore45]

Thanks but need more reference
Front of engine is where the cam gear is, right?
LH cylinder is the one that fires first
Rotate Crank 90*, now the piston is 1/2 down
Front Intake? The intake of the referenced cylinder, right?
Really does not matter which cylinder we pick, as long as we reference to same cylinder for all angles and valves.
Adjust for Intake fully open.

OK make sense the valves duration's are all about 200* of crank so the valve is set to open 10* before TDC and close 10* after BDC

 

[lantain1982]

I see the front of the engine as the camshaft facing me, the cylinder to the left hand is the one I refer too. The front intake wording should have been clearer and refers to the intake cam lobe effecting the intake valve on the LH cylinder. I have never played about trying to get better? valve events. I was happy that the engine runs. I believe that the engine is very touchy on what carby and settings one is using. I also think that insulating the intake tube fixing to the cylinder heads would overcome fuel vapourization as the tube gets very hot when running. I read this somewhere in the forum. I will do this at sometime.
Hope the above is of some help.

 

[Bowlweevil]

Facing the cam I used the cylinder to the right (farthest from the kick start gearing). I set i up like Bill said above and mine runs ok. Bill, someone told me that running retard timing will cause it to run hotter and that seems to be the case with mine anyway. Advanced timing will cause kickback but will allow for quicker throttle response. I had mine running perfect but now it wants to spray fuel out of the carb inlet when it's running. Can't seem to find that sweet spot again. BTW I'm using the Howell twin jet carb.
Mark

 

[lantain1982]

Hi Bowlweevil, Fuel spraying out of the carby is usually a sign of valve timing going astray. If its been running OK maybe check if one of the push rods has lost adjustment effecting open/closing events?. Or has the camshaft loosened on the shaft. I am also using J.Howell`s twin jet. Only need 1/4 open Idle jet and very little high speed. Still takes a bit of fidling to get it to fire up sometimes. Finger over the intake if all else fails.
For info I run on lighter fluid with a dash of two stroke oil. Plugs are very clean.
Cheers Bill.

 

[tornitore45]

Thanks is crystal clear.