High rpms = 4 stroking

Mac

New Member
Dec 3, 2009
489
1
0
Maine
Hi Norm,
I an Mac (Bill McEnery), Pretty new to MB but certainly not mech stuff. I checked out your home page, my vote is gearhead!! I really like the Home built AC. I'm certified A&P and a whole lotta other stuff.
A question for you if I may. I just built 2 "80cc" Zoom kits on schwinn riversides, I cant seem to get the motors to pull past 1/2 throttle, they just flatten out. I adj the needle, seems to run the best on the top grove. These are the stock carbs that come with the kit, I did take them apart to check for FOD etc... No problems noted but There is no jet size stamp. What do I need? a smaller jet? Where can I get them and if you could, let me know the size

Info: Amsoil Syn. 24:1, reg unleaded, NGK B7HS, new Plug wire, stock aircleaner.

If you could steer me in the right direction I would really appreciate it

Mac
 

Mac

New Member
Dec 3, 2009
489
1
0
Maine
Norm,
Received your PM. That was the post that I thought I lost.

Thanks a bunch!

Mac

.weld
 

Jonathonh

New Member
May 10, 2019
2
0
1
28
Four stroking is cause by an over rich condition.

Your jet is too big.
What if the engine starts to do it all of a sudden after years of riding? Changed the plug and leaned it out but mine still doesnt scream like used to. Note the exhaust is cut off and its ported. Did real good in the cooler months.