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Old 09-13-2010, 01:50 AM
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tvc15 tvc15 is offline
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Location: portland, OR
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Default Which carb to buy. What is the solution?

I have a GT5 with the "improved carb" and want to get better performance. Is Dell'orto SHA 16.16 the solution or maybe the CNS carb...

I have a CNS on hand and ready to go but it seems like a cluster you know what to adjust (tube that go no where, multiple adjustments)...

Rather than mess around I just want the one the works best... Suggestions?

Last edited by tvc15; 09-13-2010 at 01:51 AM. Reason: Inabiltiy to spell
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Old 09-13-2010, 06:26 AM
r00t4rd3d r00t4rd3d is offline
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Join Date: Aug 2010
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Default Re: Which carb to buy. What is the solution?

Any real carb has vents or "tubes that go no where" and multiple adjustments or 3 screws. Idle , air and fuel.

The stock carb is junk. The CNS is a small improvement. If your looking for quality you want a 18mm Mikuni carb. You can get them on ebay for about the same cost as a CNS.

The Mikuni is not a bolt it on and forget about it carb though. Mounting , jetting and screw adjustments will have to be done.

I havent made the jump to one yet but it is on my radar. I know others around have and could tell you more about the setup and install. I have owned tons of 2 stroke toys though and they all have had Mikuni carbs on them.

Last edited by r00t4rd3d; 09-13-2010 at 06:39 AM.
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Old 09-13-2010, 01:40 PM
Nougat Nougat is offline
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Default Re: Which carb to buy. What is the solution?

r00t, the CNS is a knockoff of a Mikuni carb, specifically the kind that Yamaha used on the PW80 (and probably other stuff, too). The other Mikuni 18mm carbs I'm seeing pictures of (at least the ones that are clamp on and not flange) look very, very similar in design.

Carburetor bowls need venting, that's what those "tubes that go nowhere" are for. The NT carb doesn't have those because it vents through the primer button. The NT carb also doesn't have an overflow; it just leaks out, again, through the primer button.

As for additional fiddling, there are four things to fiddle on with an NT carb - idle, throttle needle, jet, float height. On a more advanced carb, there will be more: add to that the air screw, and a pilot jet (although you probably won't need to fiddle with the pilot jet).

Last big difference between NT and CNS is the choke. NT has a choke cover, which restricts air. This air restriction makes the intake more rich, but reduced airflow over the main jet also reduces fuel, so it's not perfect. CNS has a proper choke circuit which increases fuel only, without restricting airflow, making for an easier start and better lubrication during warmup.
When asking for advice, you did not specify whether you wanted only good advice.

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