I have a 78 Puch newport.
I currently have a
15mm bing with 217 atomizer and 70 jet
Techno estoril performance pipe
Mlm velocity stack filter
Everything else is stock... ever since input the new 25mm carberator on i cant seem to get it tuned correctly. Any advice would help. Thanks
A substantially bigger carburetor and substantially more performance pipe and you’re running the stock cylinder?
You got to take that topend off who knows what’s going on with that it
It could be a 1HP restricted, it could be rings are all gummed up or previously seized who knows!
A 15 mm carburetor and a pipe needs a kit not the stock restrictive crap,
Don’t use a velocity stack that’s only good for 4 cycle engines, use metal mesh filter or k&n filters
> Probably Fred wrote:
> -------------------------------------------------------
> A substantially bigger carburetor and substantially more performance
> pipe and you’re still riding a moped?
>
> You got to take that topend off who knows what’s going on with that it then throw the rest of the bike in the trash, then throw the top end in the trash too
>
> It could be a 1HP restricted, it could be made out of cheese are all gummed up or
> previously cursed by a skrog who knows!
>
> A 15 mm carburetor and a pipe needs a kit not the stock restrictive
> crap,
>
> Don’t use a velocity stack that’s only good for smoking hash, use
> metal mesh filter or k&n filters or your mom's granny panties.
The only thing you can do at this point is quit mopeds and buy a scat pack Challenger or a mustang gt or something. There is no way those parts or any other parts can ever be put together into a running moped just give up
Wow op, its not that bad. Ask Ken nicely, and he will walk you through. Pics with circle and arrows will help Ken to steer you in the right direction.
That setup is just begging for a airsal 65 kit, with a regear...
We're just joking around that will be fine but we need some more details. Was it running good before?
I rebuilt the engine..changed piston rings and gaskets. Cleaned the original carberator. The exhaust and air filter on the original were completely trashed. So I put on the pipe and filter and had it running pretty good until I added the 15mm carb. I was looking to keep it somewhat stock just better low end torque. Should I just get a new air filter and put the old carb back on?
These are pics of my shitty setup. Any help would be greatly appreciated. Again I'm brand new to all of this so any knowledge is greatly appreciated. I know nothing about engines and figured this would be a great way to teach myself so that I could pass it on to my son.
Yeah that's great, should be a good setup once you get it dialed in. It's really hard to give tuning advice over the internet. I usually run the 14 instead of the 15 because they are cheap used and I don't notice much difference in performance but the jetting can be pretty different between the two. Also if it's a clone, you're kinda on your own, hey that rhymes. There are so many differences and qc problems with clones lots of things could be wrong. In all honesty going to a complete used 14 is probably the easiest way to get closer to being tuned, esp if you got a clone.
First check that you don't have any air leaks at the carb mounting, if you don't have an o ring in there, it's good to add one. Almost all bings leak a little without an o ring. Also make sure you don't have an exhaust air leak, or any other leaks for that matter.
Next, the main sounds like it should be close, might go up or down a little bit, tune it at wide open throttle. You'll have to get the main as close as you can for the needle jetting to work right but as you change the needle and atomizer, the main might change again. Usually it's easier to go big on the main for starters and work your way down as you lean out the bottom end.
The bing design is not very forgiving since it doesn't have any secondary jetting system. The slide, needle and atomizer are all you have to mess with. Reference Myron's page here:
https://myronsmopeds.com/category/bing-menu/
I usually start with the 1/14/196 settings and go from there, the airbox is a big restriction so removing it dramatically changes jetting. It's always better to start with the pinto/magnum guts since they had a less restricting filter. For kitted bikes usually the 24 with the slide mod (search on the forum for 24 slide mod) works the best, but the 51 slide is sometimes better for stock cylinders or if you have more air filter restriction.
Ken will probably come back and say everything I'm posting is wrong (Cunningham's law, look it up, lol) and he honestly has a lot more experience with these than I do, but he can be a real dick if you aren't doing things his way, see above. Teach a man to fish, blah blah, you'll be fine with the 15, just gotta dick around a bit more.
Thank you so much. The 15mm carb is a clone but the guy I bought it from gave me an oem 14mm carb so ill throw that on and see if it works better. The 14mm port has a small nipple on the side for oil injection so I'm not sure if that will cause an airleak. Can I stay with the 15mm port?
Cap off that oil injection port on the intake.
Yep, that oil injection nipple is absolutely an air leak.
Ok thanks a lot ill definitely cap it off.
I'm going to order a new filter. What's the best one I could put on this set up. Any recommendations?
They all kinda suck about the same, the mesh rubber dong one from treats gets you a season or two and it's cheap enough to just replace every now and then.
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