I am new, can you please advise?

[jmoney08]

I have an '08 Zuma and I have installed an aftermarket Leo Vince ZX. I am still running the stock 49 cc engine although I had the carb jetted and it runs really rich with great compression. It will almost do 40 mph but with some lag through the acceleration at 10, 18, and 27 mph. I am thinking that perhaps changing the air intake would help. Honestly, I am only guessing and have no idea. The people that did work on it said that a racing clutch would help. BTW they already installed lighter weight rollers. Any advice would be appreciated and thank you.

[yosemite]

A racing clutch will not do anything for the lag in the midrange. It is all Fuel and Air that is causeing the lags. Since they rejetted the carb Try Leaning out the Fuel Ratio Mixture Turn it 1/4 Clockwise AT A TIME and test it out if it gets better Then Turn it 1/8 and Try it Should not take more than 1/2. But you do this in increments to find the sweetspot.
Sam

[silverbergd]

I am sitting here with jmoney and we have the scooter apart and motor exposed. I am not sure where the air fuel mixture screw is located on the zuma. It is smoking fairly heavy when first starting and accelerating

[silverbergd]

Nevermind adjusting now

[yosemite]

Is this a 2 stroke or four stroke?
The Fuel Ratio Screw should be on the LEFT side of the Carb Left of Center Right Under the BIG GOLD CAP that holds the Butterfly and Throttle control wheel. Now the problem MIGHT be that the Screw has a plug on it about 1/4 diameter usually gold. If that is the case BUMMER, then you have two choices get an Aftermarket Carb that does not have it plugged up or Drill the plug out to get to the Screw. The Plug is usually about 1/8 thick so drill a 1/16 hole in the center JUST enough to take a small screw and screw it in and wiggle it out.
Sam

[silverbergd]

No plug adjusted , but it seemed to be backwards, clockwise was rich, counter was lean, smoked heavily when turned to the right

[silverbergd]

Thanks for your help, also when the after market exhaust was installed, should we seal up the extra hose that ran from exhaust to air box?

[silverbergd]

And yeah its a 2 stroke, thanks again sam

[yosemite]

Your are right if its a 2 STROKE then what it has is a AIR RATIO MIXTURE and NOT a FUEL RATIO MIXTURE.
Also the AIR RATIO is on the AIR FILTER SIDE and turning it CLOCKWISE CUTS the AIR so you get more fuel and COUNTER CLOCKWISE you are giving it more air AND less FUEL.
Also the IDLE SPEED SCREW is the CENTER SCREW Left of the AIR RATIO SCREW.
Clockwise raises the IDLE and Counter Clockwise lowers the idle, all it does is turning it in raise the SLIDER inside and Visa Versa lowers it turning the screw out.
Sam

[jmoney08]

Sam, silverbergd and I adjusted what you said and now all the problems are gone. Just went on the road and had no hesitation through the acceleration, no lag, and top speed of nearly 40mph was still there. Idled beautifully instead of stalling out. THANK YOU SO MUCH for the awesome advice. Was trying to get advice on another forum "Provo" and had no help. You made my day. Thanks again!

[jmoney08]

Only one other question in regards to this thread... Having made the adjustments, will my engine be getting enough oil? Only reason I ask is that I had to replace my piston recently due to a malfunction with my oil pump. Piston was scorched. Break in period is long over so no need to worry there. Just slightly concerned is all. Sam, will look forward to your advice on Saturday when I get those pics of airbox hoses.