Thinking of a different carb for my Puch

[RebelRider.Mike]

Hi folks, a while back I customized my Puch: http://www.mopedriders.org/viewtopic.php?f=2&t=13953

I've been fiddling with the original 14mm Bing, trying to find a good air/fuel mix. No matter what I try with jet sizes, and needle height, I'm just not getting much power.
What I've got is a 70cc kit on the E50 engine, and a slightly larger exhaust pipe. Looks like a stock pipe, but the header is larger than stock. I suspect this setup may need more air than the stock carb can provide.

I'm thinking of upgrading to a Dellorto 16.16 SHA, and a larger intake to fit. Anyone have opinions on this carb?
Seems like a lot of people use Dellortos on their E50s, and reviews I've read on this carb are pretty good.

[John]

I would look for a 17 mm Bing with the bendy intake that the Puch X had, then jet it to your satisfaction. My recollection was that delLortos seem to not be best suited on a Puch e50. Ask around on Moped Army.

[RebelRider.Mike]

Thanks John,
I've searched around Moped Army, and there seems to be a few folks who favor the 15 or 17 mm Bings. I think I'll go ahead and try that. I've already got a large assortment of Bing jets and atomizers.
I also already have the larger 15mm intake. Hopefully that's large enough to accommodate the 17mm Bing.

[John]

Just the ID which should be different. The beauty of the Puch Magnum X manifold is that it gets the carb up off the cylinder into the air. Probably a hard item to find on this side of the pond. Netherlands/Germany would be my place to hunt one down.

[RebelRider.Mike]

The 17mm Bing came in the mail today. I did a comparison between it and the 14mm spare I had handy.



The exterior differences are, the obvious 60mm ID air intake, the slightly larger "conning tower", and the clamp to the intake manifold is 3mm larger ID.
Also the fuel port is straight, and they're mirror image. I took them both apart to compare the innards.

The float bowls appear identical and interchangeable. As do the float and valves. The float pin on the 17 seems thinner though.
Although the fuel ports are different, they appear interchangeable as well. The 17 didn't come with the fuel strainer, but one will fit without restricting flow.
The idle screws are different sizes. The jet and atomizer on the 17 did not come with markings. Though they appear to be interchangeable with the regular Bing parts.
The slide needles are the same diameter, but the 17 is 3mm longer. The 17 slide is also slightly larger in OD than the 14.
The choke plates are also different sizes. The push rods for the choke plates appear to be the same diameter, although, the 17 is actually shorter.
The slider spring on the 17 is the same diameter as on the 14, but is slightly shorter with more coils. I can't measure specifically, but the 17 spring seems a bit beefier.
The cover, screws,and gasket are also slightly larger on the 17.

Well, that's probably more info than anyone wanted to know, but here it is anyway.
This 17mm carb will definitely not work with the 15mm intake I have. The OD of the intake is 3mm too small.
I suppose I could shim it, but I think I'll look for one of those larger intakes that bend away from the engine and see if I can find one that will fit better.

[John]

3 mm, a piece of 1/2" diameter thin walled copper tube might work backed into a O ring to seal.

[wardie]

[quote="John"]I would look for a 17 mm Bing with the bendy intake that the Puch X had, then jet it to your satisfaction. My recollection was that delLortos seem to not be best suited on a Puch e50. Ask around on Moped Army.[/quote]

Hey John Hi long time Wardie

I wouldn't shim too great a gap definitely need different correct intake. Talk to Benji at Treats ask him for recommendation.

[John]

Wardie,how is it on the other side of the lake? Trust everything has been good for you and all your persuits!
This guy really needs a OEM Magnum X bendy manifold though.