1QwkSport2.5r

If you cannot figure it out form the instructions provided by the manufacturer of the tank, you should sell your Diesel engine. Sell all of your engines while you’re at it, and invest in LiPo batteries and Electric motors.

Coxfledgling

I notice this thread was started many years ago by a different poster...

No matter...

You have the instructions for the tank ?

Anyways, the tank top, the black plastic round bit with a central screw, rubber bung and squeeze plate, are there 3 holes in them ?

If so, logic might dictate one hole is for the filler tube, one hole for the vent and the last hole for the fuel pick up pipe.

I don't remember if the rubber bung is diesel fuel tolerant ?

You have diesel tolerant fuel tubing which may not be as flexible as glow fuel tubing.

If your brass tubing is long enough, carefully bent to shape to act as a fuel pick up pipe. The tank is rectangular, so lay it flat so it is not "tall", and pick up pipe is just off the bottom of the tank. The filler and vent similarly bent so as to just not touch the top of the tank, when laid down. Arrange the tank so the top of the tank ( it's large side ) is just below the needle valve level, or lower, the engine should pull fuel thru ok, see video of PAW engine run on the PAW site. He uses a jam jar for a tank which is way below the engine.

When you have sussed out tank tubing etc. post pictures...

You did smooth the sharp prop blade edges ?

You will need a good finger flick technique to start the engine. Just because the running engines prop is chopping your finger off, don't expect the engine to stop !!!

A chicken still doesn't work for me on a diesel, so maybe a "rubber" finger protector or suitable glove ?

do not use an electric starter !!!!!!!!!!!!!!!!

A diesel( or glow for that matter, even a Cox 049 ) which fires fires and catches your finger does really hurt, even red paint appearing.

I have some scars to prove this caused about 55 years ago !

LIPOS, omg.......don't go there.....many many many more hazards for your inexperience...

Still, we all started out inexperienced and had to learn, by reading instructions probably.

If you don't know, you don't know. No internet in them days, how did we survive, some didn't, so be carefull.

When you do get the engine running, keep pets and kids well away from it.


Pictures pictures pictures .three thousand words...

beatsal

"The top of the tank, and fuel level, should be slightly below the level of the engine spray bar, that being the brass bit with the needle valve and fuel pipe stub."
Guess this is to prevent fuel flooding the engine? Will the fuel get to engine if fuel level is below spray bar?

ffkiwi

Yes.

beatsal

Looks like Jack does not work there anymore.

beatsal

The first video shows the fuel as Southern modelcraft sport diesel. Guess that is only available in UK?

Coxfledgling

I know Canada if that's where you live is a big country, but what does your local ( may be many miles away as far as I know, mine is a good 100 miles away .Thank god for mail order pioneered in Newtown, Montgomeryshire, Wales, UK, Price Jones ) stock, Model Technics D1000 ?

I thought you had made a home brew ?

beatsal

I have a homemade brew, looking for a backup if it does not start.

Coxfledgling

Engine securely mounted in its wooden mount with 4 screws, wooden mount securely held in vice at good working hieght, prop on properly, good fuel, compression screw set ( does the contract piston move now ? ) So engine turns over ok, a little prime of 2 drops down the venturi and engine turned over by hand ok,vertually NO assembly lub in engine, a warm place to run engine and a good prop flick technique, she should show signs of running. When you are attempting to start this little gem, unscrew the compression screw say half a turn. When she fires, you may hear a spark crack noise and compression will seem to drop a bit. This crack is hopefully the contra piston moving to reduce compression setting.

If that happens, it's a good sign.

At the new setting prime again, only two drops down the Venturi and retry. If it bursts into life, it will run for say 1 full second.

Call that a successfully initial try and call it a day, and report back. DO NOT use an electric starter, do not screw in compression screw.

Hope she bursts into brief life...

Report back as we are all interested, wishing you and the engine good luck.

beatsal

Here is a pic of my setup. No luck yet, tried starting by flicking the prop but no cigar!

Pic of setup, no luck starting yet.

1QwkSport2.5r

Dump the makeshift fuel tank setup for one. Seriously. Prime the side of the piston through the exhaust. If it doesn’t pop in 3-4 flicks, increase compression 1/4 turn. Flick it 3-4 more times. Prime the side of the piston again, and repeat. If it doesn’t start, either it isn’t primed enough, compression setting is too low, or it’s flooded.

Coxfledgling

Ah, yes, I forgot the Venturi is horizontal and at the back. Yes prime via exhaust ports, and ditch the "tank".

Coxfledgling

The fuel pipe looks like glow fuel pipe.

Perhaps a higher working hieght for the bench/engine unless you are sitting down when trying to start the engine.

See PAW site vidio of starting/running a paw " on the bench"....

beatsal

When I unscrew the compression screw, it seems as if it is free i.e. when I tighten the screw it reaches a point where cannot tighten further. Now, when I loosen from that point, it is free as if not connected to anything.

Coxfledgling

Post a picture of the head area to show the whole compression T when it screws in as far as it can without real force, IE when it makes contact with the contra piston.

Just to clarify, the engine does turn over ok at the moment ?

Over........

​​​

1QwkSport2.5r

When you back the compression screw off, flipping the engine over a few times should push the contrapiston back up. The compression screw and contrapiston are not connected/attached to each other. If the contrapiston does not move back up after backing the compression screw off, it’s probably stuck due to gummy oil. It needs to be freed up by someone experienced with diesels. If you mess it up, you’re replacing the head, contrapiston, or both.

I HIGHLY suggest getting with someone that knows how to run a diesel to help you. Otherwise you will ruin the engine in short order. I’m pretty sure this has already been mentioned, so heed that sound advice.

qazimoto

My Feedback: (1)

Before you try disassembling the engine to tap the contra upwards, try this:

Disconnect the fuel tank. Back off the comp screw a few turns so it's not touching the contra. Turn the prop to close the piston and squirt a decent prime into the exhaust. Turn the engine over at least twice by hand. Give it a hard flick. Continue till it fires. If it doesn't, continue doing this till it does. When it gives a burst it should drive the contra up. Continue till it's where you want it.

beatsal

Tried flicking it a few times - no luck. Looks like the fuel in the plastic fuel line may not be getting to the engine

Here is a pic of fuel line

beatsal

Yes, engine does turn over, in fact when I flick the prop, it turns a few times.

beatsal

Problem is how to get in touch with someone who can help solve this issue.

qazimoto

My Feedback: (1)

If you put your finger over the venturi hole and turn the engine over a few times, does it draw fuel into the line? If not there's a blockage in the venturi assembly. Just unscrew it and clear all the holes.

beatsal

Yes, it does. Now will try and unblock it.
Trying to understand this:
'When I unscrew the compression screw, it seems as if it is free i.e. when I tighten the screw it reaches a point where cannot tighten further. Now, when I loosen from that point, it is free as if not connected to anything."

When it reaches a point where it cannot tighten further would suggest that it has now contacted the contra? When loosened from that point would suggest that it is now disconnected from contra?
The argument against the above reasoning is that if disconnected from contra, it cannot adjust the compression. So, not sure how to eplain this correctly.

1QwkSport2.5r

It’s already been explained a couple times. Go back and reread the last several posts.

qazimoto

My Feedback: (1)

The initial running setting for the contra should be just a few turns down from where the comp screw touches the former. In other words wind the screw until it touches the contra and add a few more turns. Disconnect the fuel. Turn the engine over until the piston is closed. Hold it there. Prime the side of the piston (most of the fuel will run out), turn the engine over twice, flick hard, add more compression in slight increments till it fires. If it doesn't re-prime and add a little more comp. Repeat till it fires and runs out the prime. Reconnect the fuel, with the needle closed and repeat the cycle adding a turn on the needle and priming till it will run off the tank.

beatsal

Tried no luck. Although it flicks, no fire.
Not sure where the problem is i.e. fuel, engine or procedure. Is there any way of finding the root cause i.e. which of these is the culprit?