OS .15 CV-RX Starting Problem

[Jack W. Fessler, Jr.]

I just installed a new OS .15 CV-RX in my buggy, and for the life of me,
cannot get it started. I mean not even a pop.

I've been using nitro engines for 15 years, but this has me stumped. My
initial settings were per the manual, two turns out on the main needle, two
and a half turns in from carb flush position with the mixture screw. It was
very rich to the point of being difficult to pull the starter. Cleared it
out, have gone leaner on the main and mix, simultaneously and independently.
It gets easier to pull, but still nothing. I've got a good, bright glow
plug. I've tried everything from barely open throttle to over half open.

If anyone has this engine, what are your settings as running now. I'll take
those and richen them up for initial break-in.

Thanks very much.

Jack

[David Chabot]

Hi Jack,

Check out the instruction manual. I think there is an error in the
initial settings for mixture control valve. The text is wrong but the
drawings are right. If you have a slide carb, the initial setting is
2.5 turn from flush. BUT, if you have a rotary carb, the initial
position is 0.5 turn from flush.

My .15 CV-X with rotary carb started easily the first time with 0.5
turn from flush.

Good luck,

David


On Wed, 03 Sep 2003 20:57:49 GMT, "Jack W. Fessler, Jr."
<jfessler@triad.rr.com> wrote:

>I just installed a new OS .15 CV-RX in my buggy, and for the life of me,
>cannot get it started. I mean not even a pop.
>
>I've been using nitro engines for 15 years, but this has me stumped. My
>initial settings were per the manual, two turns out on the main needle, two
>and a half turns in from carb flush position with the mixture screw. It was
>very rich to the point of being difficult to pull the starter. Cleared it
>out, have gone leaner on the main and mix, simultaneously and independently.
>It gets easier to pull, but still nothing. I've got a good, bright glow
>plug. I've tried everything from barely open throttle to over half open.
>
>If anyone has this engine, what are your settings as running now. I'll take
>those and richen them up for initial break-in.
>
>Thanks very much.
>
>Jack
>

[MikeF]

whoa, hold it.
the cv-rx and the cv-x are totally different engines.
I would be inclined to suggest a full investigation. setting the carb to
factory settings, check glow plug and battery (more often responsible than
youd think) fuel delivery - complete, as in tearing down the carb to check
for defects or crap, even cylinder assembly. Its quite possible that a
political prisoner assembling these engines at gunpoint dropped dead and the
new guy who replaced him assembled a few with the cylinders 180^ off!
BTW, if you bought this locally, beat them up for this. make it their
problem. If you got it from Tower, read on...

Jack, another thought is the compression. High perf engines have sooo much
compression when new that they often dont have enough power to overcome it
on the upstroke.
Most have good luck with simply loosening the glowplug a bit, starting her,
and tighten the plug up when she seems to be running consistently

sorry, i dont have that engine, so i cant help with the needle specs. Even
if its way out she will usually pop though.
keep mew posted. oh, and cotton gardening gloves will keep the skin from
falling off your fingers. ANd ignore anyone telling you to get a starter
box...it wont work on the baja bug.

G/L, mike



"David Chabot" <david.chabot@videotron.ca> wrote in message
news:fv0dlv06511q6nlqs0pblp3cqiac99ored@4ax.com...
> Hi Jack,
>
> Check out the instruction manual. I think there is an error in the
> initial settings for mixture control valve. The text is wrong but the
> drawings are right. If you have a slide carb, the initial setting is
> 2.5 turn from flush. BUT, if you have a rotary carb, the initial
> position is 0.5 turn from flush.
>
> My .15 CV-X with rotary carb started easily the first time with 0.5
> turn from flush.
>
> Good luck,
>
> David
>
>
> On Wed, 03 Sep 2003 20:57:49 GMT, "Jack W. Fessler, Jr."
> <jfessler@triad.rr.com> wrote:
>
> >I just installed a new OS .15 CV-RX in my buggy, and for the life of me,
> >cannot get it started. I mean not even a pop.
> >
> >I've been using nitro engines for 15 years, but this has me stumped. My
> >initial settings were per the manual, two turns out on the main needle,
two
> >and a half turns in from carb flush position with the mixture screw. It
was
> >very rich to the point of being difficult to pull the starter. Cleared it
> >out, have gone leaner on the main and mix, simultaneously and
independently.
> >It gets easier to pull, but still nothing. I've got a good, bright glow
> >plug. I've tried everything from barely open throttle to over half open.
> >
> >If anyone has this engine, what are your settings as running now. I'll
take
> >those and richen them up for initial break-in.
> >
> >Thanks very much.
> >
> >Jack
> >
>

[Jack W. Fessler, Jr.]

Thanks guys for the responses. I decided to just let it sit, and go back to
it. When I did, I decided not to hit the prime button on the fuel tank.
Bam!, fired first pull, with the factory settings. I was simply flooding it,
and as you said Mike, the engine has sooo much compression normally, it was
hard to tell the diff between that and a slight hydro lock condition. In any
case, this thing is a hoot.

BTW Mike, I sent pix to your email, let me know what you think. I forgot to
mention it, but as you can see I swapped fuel tank and throttle servo
position because of the slide valve carb. I tried bellcranks, but it was
just a kluge. I also locked the tranny in forward and did away with the
reverse idler gear, works great.


"Jack W. Fessler, Jr." <jfessler@triad.rr.com> wrote in message
news:hBs5b.1$rb3.1544@twister.southeast.rr.com...
> I just installed a new OS .15 CV-RX in my buggy, and for the life of me,
> cannot get it started. I mean not even a pop.

[d r a k]

Jack W. Fessler, Jr. wrote:

> I just installed a new OS .15 CV-RX in my buggy, and for the life of me,
> cannot get it started. I mean not even a pop.
>
> I've been using nitro engines for 15 years, but this has me stumped. My
> initial settings were per the manual, two turns out on the main needle, two
> and a half turns in from carb flush position with the mixture screw. It was
> very rich to the point of being difficult to pull the starter. Cleared it
> out, have gone leaner on the main and mix, simultaneously and independently.
> It gets easier to pull, but still nothing. I've got a good, bright glow
> plug. I've tried everything from barely open throttle to over half open.
>
> If anyone has this engine, what are your settings as running now. I'll take
> those and richen them up for initial break-in.
>
> Thanks very much.
>
> Jack
>
>

Your idle needle needs to go out some more. (The needle is located on
the carbs side in the horizontal position.) The needle should be at
least 1/16the of an inch more out will cause more fuel to mix. Thus pre
firing the piston even more a simple 2 stroke engine does not have
perfect combustion. Go with factory settings if the above doesn't work
continue to pull that needle out some more. In my case I had an air leak
in the high end needle and made for a bog down in power. The carb
should be in good shape. Try using a traxxas .15 carb if you have one
which is identical, but not as good if it starts up the carb you have
can go back to OS and a replacement is suggested. OS is an inferior carb
though it should work fine with my suggestions above. Follow suit with
the choke it should be about a match stick. bleh bleh bleh you've heard
it all before. GL yo