Jetting question

Help!, I've searched but come up empty on this one..

My moped ran great until I put a high-flow filter on it, when I noticed it was starting to run a little lean (obviously). So I drilled the jet (stock size 47 according to haynes manual, not labeled on the jet), but got a little excited and drilled wayyy too big. I ordered a new one from treats (size 50). It'll start and run with the choke on (albeit very slowly); and it'll idle with the choke off - however, if I give it any more throttle than that, it'll rev up for maybe a second, then die. Solutions?


Re: Jetting question

Sorry; some more details. It's an SHA carb, so no adjustments. Also, I noticed that the screw head part of the jet was quite a bit taller than the stock jet. Would this make a difference?

Re: Jetting question

I hate to keep adding to this, but in case somebody glances at it..

I scraped some shite off of my stock jet; and despite the haynes manual saying it's a size 47, the one I pulled out was...80.

I'd say that's quite a bit of a difference. Obviously the 50 was waaaaaaay too lean.

So, in conclusion, to the other 4 people on the face of the earth that own NVTs - check your physical jet, not the manual.


Re: Jetting question

Hi, im looking to put a new air filter on my 2005 derbi gpr 50 and im not sure how to upjet, could you tell me how?


Re: Jetting question

Dude, that thing is HOT! Wish we had bikes like that in the states.. What kind of carb is on it?

Re: Jetting question

order bigger jet, take bottom off carb remove jet that needle goes through ,get a bigger one from moped shop. put bigger one in. ride take out spark plug and do a plug chop. repeat till you get the right jet in there

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