Removing Carb Body from TD 0.049

proctor Thu Feb 23, 2012 9:30 am

Have done a search but no luck finding answers.

Have stripped and cleaned my TD 0.049 and it's down to
just crankcase and plastic carb body. Is the body screwed
on or push fit, it is very tight, any tips for removal. (cracked,
want to fit a new one).

Also, I would like to fit a throttle ring and run slow,
not interested in top end rpm. Which cylinder number should
I use, head gaskets etc. Only new piston/cyl set I have is a
#7 , one transfer and one boost each side, doesn't seem ideal.
john

GermanBeez Thu Feb 23, 2012 9:38 am

have you unscrewed the body retainer nut? if not,
get your cox wrench and use it to unscrew the aluminum ring that is in front of the plastic body.
it's basically an aluminum ring with a thread inside.
after you took it off, you'll have to use a little force to get the body off,
don't be afraid they just have quite a tight fit Smile

Beez

**Cribbs74** Thu Feb 23, 2012 9:51 am

GermanBeez wrote:have you unscrewed the body retainer nut? if not,
get your cox wrench and use it to unscrew the aluminum ring that is in front of the plastic body.
it's basically an aluminum ring with a thread inside.
after you took it off, you'll have to use a little force to get the body off,
don't be afraid they just have quite a tight fit
Beez

What he said..... Sometimes they are a bit of a tight fit and sometimes old fuel "glues" them on. Try not to use the venturi to pull on as it is brittle.

I use the stock#4 cylinder it came with my throttle ring and it runs really well and idles nicely.

John Goddard Thu Feb 23, 2012 9:59 am

cribbs74 wrote:
GermanBeez wrote:have you unscrewed the body retainer nut? if not,
get your cox wrench and use it to unscrew the aluminum ring that is in front of the plastic body.
it's basically an aluminum ring with a thread inside.
after you took it off, you'll have to use a little force to get the body off,
don't be afraid they just have quite a tight fit
Beez

What he said..... Sometimes they are a bit of a tight fit and sometimes old fuel "glues" them on. Try not to use the venturi to pull on as it is brittle.

I use the stock#4 cylinder it came with my throttle ring and it runs really well and idles nicely.

Work to be done on mine Ron
It's like an on and off switch

proctor Thu Feb 23, 2012 10:00 am

Yes I have already removed screwed retaining ring, just crankcase
and carb body left, but is carb body screwed on or just very tight push
fit, would be good to know before I apply judicious force.
Has been soaking overnight in fuel then washed and scrubbed in
thinners.
Thanks for info on cylinders, as found had a #2 , just one transfer port
but raised section at cyl base so no good for throttle ring.
john

GermanBeez Thu Feb 23, 2012 10:01 am

it's just pushed on there, just grab a towel, wrap it around, and pull like
Hercules!

**Cribbs74** Thu Feb 23, 2012 10:11 am

John Goddard wrote:
cribbs74 wrote:
GermanBeez wrote:have you unscrewed the body retainer nut? if not,
get your cox wrench and use it to unscrew the aluminum ring that is in front of the plastic body.
it's basically an aluminum ring with a thread inside.
after you took it off, you'll have to use a little force to get the body off,
don't be afraid they just have quite a tight fit
Beez

What he said..... Sometimes they are a bit of a tight fit and sometimes old fuel "glues" them on. Try not to use the venturi to pull on as it is brittle.

I use the stock#4 cylinder it came with my throttle ring and it runs really well and idles nicely.

Hmm, John are you using Bernie or Matt's ring? I have one from Matt installed on mine and the only thing I noticed is if I close it too much I get a "pop" when I open it back up and the engine quits. Used within an acceptable range it works just fine.

Work to be done on mine Ron
It's like an on and off switch

**RknRusty** Thu Feb 23, 2012 10:12 am

May need some heat to loosen it up.

microflitedude Thu Feb 23, 2012 10:23 am

If it is old and cracked, why not just break it off?

proctor Thu Feb 23, 2012 10:31 am

Done it ! No matter how hard I twisted, wouldn't budge but a single edged
razor applied carefully to the joint just slipped in, worked razor round
and it's off. Absolutely no damage!!
As a matter of interest, left mounting lug has 2 stamped on it perhaps to
identify the cyl to be fitted.
Will try the #7 assembly, with 3 head shims fitted and report back.
This John got his throttle ring from Bernie and it appears identical to
one I have from 80,s
John

proctor Thu Feb 23, 2012 10:38 am

Hi Dude,
Could have broken it off but want to try a repair per existing thread but
using high tensile golf club head epoxy which may or may not work but it will at
least be same color, black as throttle body.
John

proctor Thu Feb 23, 2012 10:50 am

Just for completeness and for benefit of other newbies. Yes it was
just stuck with old fuel, but trying to twist it to free it was a no no.
There is a raised register on the body molding that that makes twisting
impossible.
John

**Cribbs74** Thu Feb 23, 2012 10:51 am

proctor wrote:Done it ! No matter how hard I twisted, wouldn't budge but a single edged
razor applied carefully to the joint just slipped in, worked razor round
and it's off. Absolutely no damage!!
As a matter of interest, left mounting lug has 2 stamped on it perhaps to
identify the cyl to be fitted.
Will try the #7 assembly, with 3 head shims fitted and report back.
This John got his throttle ring from Bernie and it appears identical to
one I have from 80,s
John

That#2 on the lug denotes what type of crank was to be installed. That's what Mudhen said and I am inclined to believe him. I have only seen that on .051 TD's though. The stock .049 TD cylinder should be a #4 and a stock .051 should be #5.

Cox International Thu Feb 23, 2012 11:20 am

Here is the file we send to someone inquiring:

Carburetor body installation

• Unscrew needle valve
• Unscrew venturi
• Remove needle valve body & spring
• Remove backplate
• Remove cylinder
• Remove piston
• Stand crankcase upright, drive-plate facing upwards
• Insert prop screw as deep as possible
• Tap with hammer until drive-plate separates from crank
• Unscrew collet
• Wedge flat tool between carb body and crankcase and twist
• (carb body is pressed on, not screwed)
• Press in new carb body
• Re-assemble engine

For ease of dis-assembly / assembly we sell the following tools:

• Wrench
• Dis-assembly tool
• Assembly tool

Cox International Thu Feb 23, 2012 11:26 am

Proctor,

The OEM cylinder on a TD 049 is the #4, as was correctly stated in this thread. Hpwever, that version is SPI (Sub Port Induction). Although the throttle ring will work on that cylinder, it is not ideal and you are better off negating the SPI. If you can find in your collection a cylinder such as this one:

http://coxengines.ca/product.php?productid=119&cat=27&page=1

It is ported inside identical to the # 4 but is non-SPI. Some of the later Black Widow cylinders were non SPI and they may work but the porting was not quite the same as the #4.

**Cribbs74** Thu Feb 23, 2012 11:35 am

Bernie,

Good instructions! I don't agree with seperating the body with a tool wedged between the body and crank though, unless that body is to be discarded. Even if that was the case you could easily damage the crankcase if you were not super careful and ruin the sealing surface on the crankcase. I can just see someone unfamiliar with Engine dissassembly jamming a large slot screwdriver in there to pry the body off.

Cox International Thu Feb 23, 2012 11:39 am

Fair enough Ron and we shall revise the instructions to clarify that it should be a plastic or wooden "tool".

Thanks for pointing that out.

Cox International Thu Feb 23, 2012 11:45 am

Here she is bounce

Carburetor body installation

• Unscrew needle valve
• Unscrew venturi
• Remove needle valve body & spring
• Remove backplate
• Remove cylinder
• Remove piston
• Stand crankcase upright, drive-plate facing upwards
• Insert prop screw as deep as possible
• Tap with hammer until drive-plate separates from crank
• Unscrew collet
• Wedge flat object between carb body and crankcase and twist. Use a plastic or wooden object and not a metal one to prevent scratches – A med-sized flat screwdriver with the tip taped over for instance is an option. (Carb body is pressed on, not screwed)
• Press in new carb body
• Re-assemble engine

For ease of dis-assembly / assembly we sell the following tools:

• Wrench
• Dis-assembly tool
• Assembly tool

John Goddard Thu Feb 23, 2012 1:25 pm

Ah perhaps my problem mine is spi.
It go's at 17k 12k or 0 with nowt in between those 3 figures.
If the ring fits I'll give it whirl with the original Sure start cylinder but obviously
because power is at a premium for the O/Timer if it drops below 17k I'll go
stick the Tee Dee top end on and if I'm 'stuck' with a 3 (2) speed throttle
c'est la vie.
Smile

**Cribbs74** Thu Feb 23, 2012 1:37 pm

Cox International wrote:Here she is

Carburetor body installation

• Unscrew needle valve
• Unscrew venturi
• Remove needle valve body & spring
• Remove backplate
• Remove cylinder
• Remove piston
• Stand crankcase upright, drive-plate facing upwards
• Insert prop screw as deep as possible
• Tap with hammer until drive-plate separates from crank
• Unscrew collet
• Wedge flat object between carb body and crankcase and twist. Use a plastic or wooden object and not a metal one to prevent scratches – A med-sized flat screwdriver with the tip taped over for instance is an option. (Carb body is pressed on, not screwed)
• Press in new carb body
• Re-assemble engine

For ease of dis-assembly / assembly we sell the following tools:

• Wrench
• Dis-assembly tool
• Assembly tool

Looks good! Very well thought out and detailed

**RknRusty** Thu Feb 23, 2012 1:46 pm

Damn, Cribbs, great avatar. I wish I'd thought of it first.

**Cribbs74** Thu Feb 23, 2012 1:48 pm

RknRusty wrote:Damn, Cribbs, great avatar. I wish I'd thought of it first.

Thanks, Just popped into my head, I love 1960/70's box art. Snap a pic of the jumpin bean decal!

proctor Thu Feb 23, 2012 5:01 pm

Thank for all the support, excellent! The new cyl assembly I am
using is marked #7 but when I checked against my tech data
(listing of thread sizes and listing of cyl porting) the only one
that matched was the venom porting. I have just checked and
there is no spi so it is certainly the one that Bernie kindly
pointed me to and since I purchased it from him recently that
is no surprise. The #7 on cyl did surprise me though since it
would have one transfer port and no boost ports.
Honest! no prizing involved just very careful insertion of
razor blade. Have been dismantling and building engines for years,
but I can see how what I said might mislead a beginner.
Interesting about 2 stamped on engine lug. How would I know if
I had a 0.0 51 rather than 0.049 ?
John

Cox International Thu Feb 23, 2012 5:30 pm

John,

Cox made more than one version of a #7 cylinder. Some of the Surestart cylinders were also stamped with that #.

The 051 piston has a "score" at the bottom such as in a "ring" cut into the metal. Also, try pushing it into a .049 cylinder. It it fits, it's not a .051.

proctor Thu Feb 23, 2012 6:10 pm

Bernie,

Pressed the little ' Thanks' box at your answer about 051 but not
sure what it does.
Thanks for taking the time to help me out, and a big thank you for
doing what you do for the hobby. Without Cox International to provide
the spares and tech support these little engines would be obsolete.
John

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Removing Carb Body from TD 0.049