Keil Kraft Outlaw for Ponte 2023

[leccyflyer]

Well the D2000 fuel is working better than the D1000 anyway. I'm now getting many more starts with the PAW 1.49, but the longest sustained run I've had is 15 seconds and that was backwards. Mostly it's firing in 3-5 second bursts before stopping, it's not responding to the compression screw very much, just stopping.

One thing I've noticed is that the entire needle valve assembly rotates when the throttle arm is moved. I don't recall that being the case when I last operated an engine, years ago.

[bluejets]

One thing I've noticed is that the entire needle valve assembly rotates when the throttle arm is moved. I don't recall that being the case when I last operated an engine, years ago.

Think you'll find that's the way it is......fairly simple arrangement with the needle vave assy attached to the barrel.

[Pchristy]

If its not responding to the compression screw, the contra-piston is probably stuck. This can be tricky to free off, unless you fancy stripping the engine. The crude way of doing it is to back the compression screw right off, warm up the cylinder head with a hot air gun, then deliberately hydraulic lock it to shove the contra-piston up. You can bend the conrod doing this, so be careful! Also, use gloves, as a hot air gun will get that cylinder head quite hot!

Running in short bursts suggests a blockage in the fuel supply. Having said that, running backwards won't provide much suction in the venturi anyway. Starting backwards suggests over compression (see above!).

Yes, the needle assembly does rotate with the throttle barrel. These are very simple throttles, but they work surprisingly well!

P.S. If you get some D-3000, you can mix it 50/50 with D-1000 to produce D-2000-ish! Saves throwing away the D-1000.

[leccyflyer]

Thanks Pete - though getting a litre of D3000 would mean that my fuel costs for the wee PAW is on a par with a tank of real diesel

I've realised that I'm trying to start it with a Robbe Dynamic 7x4" prop and it would be far better with an 8x4" prop to give it a bit more flywheel effect. Of course I've loads of electic 8x4", but none suitable for either IC, or the stresses and strains of flick starting - those APC-E's don;t take any prisoners.

The compression screw works and with it turned in you can't turn the engone over at all, so the contra piston is moving, it's just when I get the engine to start it isn't having a huge effect when I wind it in, or out. I'm definitely getting a lot more burps and short runs, compared to a couple of days ago, so will persevere, with a larger prop, in due course. Once I've run a few tanks through the engine and got it where It'll reliably start I'll be ready for that diesel maiden flight.

[leccyflyer]

The combination of D-2000 and the 8x4" prop has had a positive impact, in that I'm now getting regular 15-30 second bursts of running, with the longest now up to a minute. It seems to be getting easier, but still isn't quite right. Maybe it's just my lack of diesel-foo. I'm certainly covered in castor oil and kerosene though.

[Martin]

Maybe the contra piston is still too tight. It should intermittently misfire when you loosen off the compression, and sound harsh when slightly over-compressed. The sweet spot is in the middle, and as the engine warms up, you have to back off the comp a little to keep it sweet. Needle valve adjustment is similar to a glow engine, but always keep it on the rich side of maximum RPM.

[Martin]

You should be able to back off the comp any time the engine is running, and get it misfiring - this is a good way of running in a diesel, as it reduces power and heat build up. If backing off the comp screw makes no difference, then it's because the contra piston is sticking in the bore.

[leccyflyer]

Thanks Martin

The motor runs are getting better every day. I had a decent extended motor run of about 2 minutes this morning, with the motor revving nice and smoothly. Most of the runs it is misfiring somewhat and what I would describe as four stroking, as remembered from my days operating glow engines - certainly not smooth or at even moderate revs. That was reserved for that one longer, smoother run. There's quite a bit of black exhaust goo on top of the cylinder head, which I think is coming out through the compression screw. I'd forgotten how messy these things are and am severely rethinking my plan to just swap the one wing between the electric and diesel Outlaw. I can see me building a second wing to keep it clean for the Electric Outlaw.

Oh that smell though....

[Tobe]

.... the old diesel perfume! Remember that you cannot wash out a stain of diesel exhaust burned oil from you clothing how hard you try so I would recommend a diesel shirt!
...and yes, the sound is different between a diesel and a glow!
... you could always add a nut on the compression screw and tighten slightly, some diesel will need it to stop the compression screw to rotate freely.
…and last, a diesel looses power as it’s getting warmer after some running i.e. less comp!

[leccyflyer]

PAW 1.49 continues to improve with more 3 minute runs this afternoon, the last of which drained the tank and the motor sounds much sweeter.

Point taken about the smell - I've tracked down my old lab coat which will be my favoured attire for running in. I'm also likely to move outdoors, or at least face the exhaust out the door, for future runs, as the fumes get a wee bit too overpowering indoors, lovely though they are, they have taken hours to not fully disperse.