Log in
Search
Latest topics
» Cox Texaco and Texaco Jr. built with Kustom Kraftsman's parts.by BillLee Today at 1:06 pm
» COX .020 RC PROJECT
by TD ABUSER Today at 11:30 am
» Jim Walker Firebaby
by rdw777 Today at 9:36 am
» Project Cox .049 r/c & Citabrian Champion
by rdw777 Today at 9:27 am
» OS MAX-D
by Yabby Today at 6:09 am
» Irvine Mills .75 replica
by ffkiwi Today at 5:29 am
» Happy Birthday Robert ( Rsv1cox )
by Kim Today at 3:48 am
» **VOTE-ON-THE-NEXT-COX-ENGINE-OF-THE-MONTH** (October 2024)
by GallopingGhostler Today at 12:01 am
» WILLY NILLY
by MANDALAY Yesterday at 10:56 pm
» Stick built rubber powered Scientific ME-109
by DPCM Yesterday at 5:36 pm
» The Cabin.........A carpenters nightmare.
by rsv1cox Yesterday at 5:26 pm
» Cox 020 PeeWee rebuild questions
by rdw777 Yesterday at 2:12 pm
Cox Engine of The Month
Can a Cox .049 Tee Dee run left-hand?
Page 1 of 1
Can a Cox .049 Tee Dee run left-hand?
Is it possible to run a Cox .049 Tee Dee "backwards", even poorly, if the crank is not changed to a left-hand version?
define "poorly"
Yes i have had engines run backwards.
They barely ticked over but kept running.
Most common if the engine is almost flooded.
One way this happens is when the engine is flipped to slow by hand and the engine fires back and keeps running.
The rpm is far to low for any meaningfull trust (even with the correct rotation propellor)
They barely ticked over but kept running.
Most common if the engine is almost flooded.
One way this happens is when the engine is flipped to slow by hand and the engine fires back and keeps running.
The rpm is far to low for any meaningfull trust (even with the correct rotation propellor)
cmulder- Gold Member
- Posts : 279
Join date : 2022-02-10
Re: Can a Cox .049 Tee Dee run left-hand?
cmulder wrote:Yes i have had engines run backwards.
They barely ticked over but kept running.
Most common if the engine is almost flooded.
One way this happens is when the engine is flipped to slow by hand and the engine fires back and keeps running.
The rpm is far to low for any meaningfull trust (even with the correct rotation propellor)
Thanks and that's what we figured.
Someone bought an engine on eBay. After our OP the chap messaged that the engine runs well LH but "rough" RH. Just wanted to give him a reliable answer.
Re: Can a Cox .049 Tee Dee run left-hand?
And here I was hoping to see a run of left hand cranks. Oh well.
_________________
Never enough time to build them all...always enough time to smash them all!
944_Jim- Diamond Member
-
Posts : 2018
Join date : 2017-02-08
Age : 59
Location : NE MS
close the fuel line
Cox International wrote:Thanks and that's what we figured.
Someone bought an engine on eBay. After our OP the chap messaged that the engine runs well LH but "rough" RH. Just wanted to give him a reliable answer.
The ways i happend on mine is when fuel pools up in the crankcase and the engine runs on that.
The air intake timing is wrong so the engine is getting only a little air.
In a way its like ideling on a rc carb and then verry rich.
When this happens one easy way to cure it is to either pull off the fuel line or pinch it to stop any aditonal fuel entering the engine and let it run dry backwards.
You can also close the needle but then you need to keep count to open it back to the right position once dry.
Then try to restart without priming and if that does not work (fast enough) close the needle a little and prime.
All above asumes its coused by fuel pooling in the crankcase other ways might also be possible.
cmulder- Gold Member
- Posts : 279
Join date : 2022-02-10
Re: Can a Cox .049 Tee Dee run left-hand?
I have found similar, that when I accidentally flood a TD 049 it will backfire and the spinner will come off. I have not had it actually run backward, but it certainly fired at the wrong time and backfired. Once the flood is gone the engine runs fine. I run hard tanks and find that its important the tank and engine NVA be alligned properly and when fueling, I squeeze the fuel line so as that none goes into the engine, then very light prime of the cylinder, turn the prop and suck the fuel up to the venturi and it will start very easily. But if you flood the engine it will backfire, especially if you have a very good battery and good glow plug. backfiring of the sort I described is an attempt to run backwards, but the crank timing should prevent it from actually running, though it seems some have had them run backward very poorly as would be expected as the crank port timing is completely wrong for running backward.
Yabby- Platinum Member
-
Posts : 712
Join date : 2021-06-08
Location : Yorke Peninsula South Australia
bumping against the compression
One critical condition for it to happen is that the engine is just bumped against compression allouwing it to fire and kick back.
Most common this happens when the flipping of the prop is to slow/weak.
And when you experience this condition, you can also use it by bumping the prop the wrong way so the engine fires back in the right direction.
Casually twisting the spinner with your thumb and index finger makes for good bragging rights when it starts that way.
This bumping and back fire is also how i hand start my saito four stroke engine.
Its a vicious bastard when it comes to backfireing (is that a word?) and for trowing props.
For that reason its fitted with a split nut that is locked in place.
ALso always use a chicken stick on it and durable graupner props (apc might be to brittle and sharp)
Most common this happens when the flipping of the prop is to slow/weak.
And when you experience this condition, you can also use it by bumping the prop the wrong way so the engine fires back in the right direction.
Casually twisting the spinner with your thumb and index finger makes for good bragging rights when it starts that way.
This bumping and back fire is also how i hand start my saito four stroke engine.
Its a vicious bastard when it comes to backfireing (is that a word?) and for trowing props.
For that reason its fitted with a split nut that is locked in place.
ALso always use a chicken stick on it and durable graupner props (apc might be to brittle and sharp)
cmulder- Gold Member
- Posts : 279
Join date : 2022-02-10
Re: Can a Cox .049 Tee Dee run left-hand?
cmulder wrote:
Casually twisting the spinner with your thumb and index finger makes for good bragging rights when it starts that way.
Now I see why they are called spinners.
SNAP says my fingers. Brappp says the engine. I like it when will fire right up that way.
_________________
Never enough time to build them all...always enough time to smash them all!
944_Jim- Diamond Member
-
Posts : 2018
Join date : 2017-02-08
Age : 59
Location : NE MS
Re: Can a Cox .049 Tee Dee run left-hand?
For my 4 strokes and other engines that have a tendency to loosen the prop, I make sandpaper discs glued back to back with a hole in the middle and place it on the drive washer prior to installing the prop. No more loose props, I've never had one loosen since doing this.
Ken Cook- Top Poster
- Posts : 5609
Join date : 2012-03-27
Location : pennsylvania
Re: Can a Cox .049 Tee Dee run left-hand?
cmulder wrote:
This bumping and back fire is also how i hand start my saito four stroke engine.
Its a vicious bastard when it comes to backfireing (is that a word?)
OS recommends that I start my FS.60 that way. It's true. It starts much easier on the reverse bump than flicking through compression. I'd just about mastered starting it with one bump, but next time I ran it I had an audience and it refused to fire. I panicked and without thinking gave it a big flick through compression and paid the price. That 12" wooden prop bit really hard, taking a chunk of my finger through a leather glove. I won't do that again. Time to get a new insert for my starter.
Oldenginerod- Top Poster
- Posts : 4010
Join date : 2012-06-15
Age : 61
Location : Drouin, Victoria
Page 1 of 1
Permissions in this forum:
You cannot reply to topics in this forum