Runner

Coxfledgling Tue Aug 29, 2023 2:32 pm

Rumour has it this engine now runs on its tank ?

kendias Tue Aug 29, 2023 5:40 pm

quote="Coxfledgling"]Rumour has it this engine now runs on its tank ?[/quote]
True, ran for a few secs after priming i.e. injecting a few drops in ex. port. Now trying to make it run continuous.

roddie Tue Aug 29, 2023 6:49 pm

kendias wrote:
Coxfledgling wrote:Nice one Roddie, oe tank, starter spring and ans silencer too !

Mine had a none anodised cylinder back in the day.

Perhaps a "warm air gun" rather than a naked flame pre warmer...less of a fire risk. Sometimes i "held" the cylinder to warm it with body heat for reluctant starters buy from memory had no problems with my DC's.

May I ask, on yours, was the back plate pre drilled and threaded for the centre tank screw ?

Also, the spray bar, two jet holes or just the one ?

If mixture needle unscrewed a bit and an aerosols sprayed into the fuel pipe stubs, the spray will be seen ?

Anyways, waiting for ken's picture of the spray bar.....
Sent pics.
The starter spring - do you actually use it to start the engine?

Hey.... The DC Merlin that I pictured.. was given to me by CEF member IAN1954. It's the only compression ignition model engine that I own.. and I have not tried to run it. I thought it important to source the fuel components... for when the opportunity presented itself.

Coxfledgling Wed Aug 30, 2023 1:24 am

Hi Roddie,

Nice one, they are good little engines and run well being good starters when in good condition.

Could you establish if yours has two fuel jet holes in the spray bar ?

All the spray bars in my DC spares box have two fuel jet holes...

Ken, when your "blurps" into life is there fuel all the way up to the spray bar ?

The finger over the Venturi and say 3 prop revolutions will/should make this happen...

With fuel all the way up to the spray bar and it burps into life, any air bubbles in fuel pipe and any bubbles around back plate ?

kendias Thu Aug 31, 2023 7:25 pm

Coxfledgling wrote:Hi Roddie,

Nice one, they are good little engines and run well being good starters when in good condition.

Could you establish if yours has two fuel jet holes in the spray bar ?

All the spray bars in my DC spares box have two fuel jet holes...

Ken, when your "blurps" into life is there fuel all the way up to the spray bar ?

The finger over the Venturi and say 3 prop revolutions will/should make this happen...

With fuel all the way up to the spray bar and it burps into life, any air bubbles in fuel pipe and any bubbles around back plate ?

Yes, there is but a small bubble at start which disappears when I prime. Just tried with 3 prop revs as you said and it ran twice for about 10 secs. Like to send a video but need someone to take the video as I try to start. Not sure if any other way.

Coxfledgling Sun Sep 03, 2023 3:50 am

Hi ken,

Internet really poor here...

So engine starts and runs for ten seconds or so, a good sign, but why does it stop running ?

Fuel supply ?

Is tank vented and tank full ?

Engine going tight ?

Ten seconds or so is a long time to run on fuel ingested via priming etc., So the two caused mentioned need checking out...

Is tank full ( good amount of fuel in tank, your tank looks quiet big and quite a large diameter ) ?

Bubbles seen in fuel pipe close to end of ten second run and engine seems to surge a few times then stops ?

Engine goes tight, does it go tight ?

Suggest a better tank set up. Smaller diameter and taller tank which is vented.

Over to you...

kendias Sun Sep 03, 2023 1:16 pm

Coxfledgling wrote:Hi ken,

Internet really poor here...

So engine starts and runs for ten seconds or so, a good sign, but why does it stop running ?

Fuel supply ?

Is tank vented and tank full ?

Engine going tight ?

Ten seconds or so is a long time to run on fuel ingested via priming etc., So the two caused mentioned need checking out...

Is tank full ( good amount of fuel in tank, your tank looks quiet big and quite a large diameter ) ?

Bubbles seen in fuel pipe close to end of ten second run and engine seems to surge a few times then stops ?

Engine goes tight, does it go tight ?

Suggest a better tank set up. Smaller diameter and taller tank which is vented.

Over to you...

Tank is vented i.e. the lid of tank in prev pic is left open. Bubbles don't surge i.e. before start I try to ensure no bubbles.
Tank dia is @ 1.75 in.
Engine seems to lose speed after starting, runs for few secs and stops. Now, will try after adding a little more ether.

kendias Mon Sep 04, 2023 10:47 am

kendias wrote:
Coxfledgling wrote:Hi ken,

Internet really poor here...

So engine starts and runs for ten seconds or so, a good sign, but why does it stop running ?

Fuel supply ?

Is tank vented and tank full ?

Engine going tight ?

Ten seconds or so is a long time to run on fuel ingested via priming etc., So the two caused mentioned need checking out...
As you suggested, using a smaller dia tank per pic attached. Will make sure the jevel of fuel in the tank is above the engine intake. Will try it and see.

Is tank full ( good amount of fuel in tank, your tank looks quiet big and quite a large diameter ) ?

Bubbles seen in fuel pipe close to end of ten second run and engine seems to surge a few times then stops ?

Engine goes tight, does it go tight ?

Suggest a better tank set up. Smaller diameter and taller tank which is vented.

Over to you...
Tank is vented i.e. the lid of tank in prev pic is left open. Bubbles don't surge i.e. before start I try to ensure no bubbles.
Tank dia is @ 1.75 in.
Engine seems to lose speed after starting, runs for few secs and stops. Now, will try after adding a little more ether.

Coxfledgling Mon Sep 04, 2023 11:45 am

Do you like mulberry wine ?

No, do not have fuel level above spray bar, which had been stated earlier...

What's happened to the compression screw "*Tommy bar " ???

kendias Tue Sep 05, 2023 4:30 pm

Coxfledgling wrote:Do you like mulberry wine ?

No, do not have fuel level above spray bar, which had been stated earlier...

What's happened to the compression screw "*Tommy bar " ???

It is in the pic i.e. the black bar on top

Levent Suberk Tue Sep 05, 2023 4:49 pm

Fuel air mix spray nozzle is at center? Nozzle exactly looking down?

kendias Tue Sep 05, 2023 5:08 pm

Levent Suberk wrote:Fuel air mix spray nozzle is at center? Nozzle exactly looking down?

Not sure what you mean? The spray nozzle goes into the mounting hole of the engine. Will recheck if nozzle exactly looking down

Levent Suberk Tue Sep 05, 2023 6:36 pm

I see that spray nozzle is in center, but spray nozzle need to look down, at least I know.

Engine seems old. Disassemble and clean it and examine what is wrong inside especially compression screw.

kendias Wed Sep 06, 2023 1:14 pm

Coxfledgling wrote:Hi ken,

Internet really poor here...

So engine starts and runs for ten seconds or so, a good sign, but why does it stop running ?

Fuel supply ?

Is tank vented and tank full ?

Engine going tight ?

Ten seconds or so is a long time to run on fuel ingested via priming etc., So the two caused mentioned need checking out...

Is tank full ( good amount of fuel in tank, your tank looks quiet big and quite a large diameter ) ?

Bubbles seen in fuel pipe close to end of ten second run and engine seems to surge a few times then stops ?

Engine goes tight, does it go tight ?

Suggest a better tank set up. Smaller diameter and taller tank which is vented.

Over to you...

kendias Wed Sep 06, 2023 1:18 pm

kendias wrote:
Coxfledgling wrote:Hi ken,

Internet really poor here...

So engine starts and runs for ten seconds or so, a good sign, but why does it stop running ?

Fuel supply ?

Is tank vented and tank full ?

Engine going tight ?

Ten seconds or so is a long time to run on fuel ingested via priming etc., So the two caused mentioned need checking out...

Is tank full ( good amount of fuel in tank, your tank looks quiet big and quite a large diameter ) ?

Bubbles seen in fuel pipe close to end of ten second run and engine seems to surge a few times then stops ?

Engine goes tight, does it go tight ?

Suggest a better tank set up. Smaller diameter and taller tank which is vented.

Over to you...

Is having a smaller dia better? I did try with smaller dia as in pic, had some improvement but no dice.
When I prime i.e. block air intake, fuel comes to the needle valve, when I stop, it goes back

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