2003 mods

Salient/Riva 50, Beluga/ Riva 80, Razz, Jog, Vino, C3, BWs and Zuma scooters.
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thephil26
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2003 mods

Post by thephil26 »

HEY,

I SENT THE LETTER BELOW TO SEVERAL ZUMA PERFORMANCE PARTS DEALERS. ONLY A COUPLE GOT BACK TO ME. THE ONES THAT DID SUGGEST 1. PIPE 2. BBK/CARB 3. VARIATOR 4. GEARING.

HERE IS MY THOUGHT ON ALL OF THIS. I DON'T WANT TO BUY A PIPE THIS YEAR, THEN NEXT YEAR A BBK/CARB AND FIND OUT THE PIPE I HAVE WILL NOT WORK CORRECTLY WITH THE NEW BBK/CARB. WITH THAT SAID, I DON'T WANT TO THROW A PIPE ON THIS YEAR JUST TO THROW A PIPE ON. I WANT SOME INCREASE IN PERFORMANCE WITH THE PIPE NOW, THAT WOULD BE BOOSTED EVEN MORE WHEN I DO THE BBK/CARB.

ALSO, WHAT PIPE AND BBK/CARB DO YOU GUYS USE AND WHAT ELSE DID YOU HAVE TO DO TO GET IT ALL TO WORK TOGETHER? JETTING, CRANK... ANY OTHER INFO WOULD BE A HUGE HELP.

I am thinking about doing some performance upgrades to my 2003 50cc Yamaha Zuma. I am not going to be racing this scooter. I would like to get more torque and top speed. I don't want to have to wait until I don't see any traffic for 2 miles before I can pull out without getting run over. Also, a top speed of at least 45 MPH would let me ride on more streets than I currently can. I'm not talking about interstate highways or anything like that. Just getting to my local WalMart requires me driving on a stretch of road where the speed limit is 45 MPH. It takes a long time for my stock Zuma to get up to around 38 MPH, so...
I have been involved in racing for over 36 years with all types of vehicles for go karts to formula cars. I have held every position possible on a race team and I am very mechanically inclined. Basically what I am saying is, making modification to my Zuma would not be a big deal to me.
I am not worried about whether any modifications will be “plug and play”. I feel very comfortable about tuning.
I understand that making modifications to my scooter may effect reliability. With that said, reliability is still important to me. In other words, I am not looking to push my scooter to the performance max. All I want is the most bang for my buck I can get and get some more performance.
What I don't want to do is spend money I don't have to waste. I am fine with spending some money to get a performance boost, but my budget is tight. I would really like to stay under $400 this go around. It may not be a problem to invest a little more money in a year or so, but right now $400 is my max for sure.

Thanks
Phil
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Florida Antique
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Re: 2003 mods

Post by Florida Antique »

Although I am no expert, here is my experience. I have 2 Zumas, an 04 and an 05. I bought both broken. The 05 had a bad clutch and flat variator weights and a bad belt. The 04 sucked part of a reed in and destroyed the cylinder and piston. I fixed the transmission on the 05 with stock parts so it basically runs like a stock Zuma with a top speed of 38 to 40. I went ahead and put a 70cc kit on the 04 to see if I could make it a little faster. It did not do anything to the top speed of the bike. It still will run 40 mph it just gets there a lot quicker than the stock Zuma. The reason for this I believe is that it is running the stock muffler. I think that pipe is designed to keep the RPMs of the engine at a certain level. With no extra RPMs, there is no extra top speed. The other difference I noticed was the stock starter is no longer strong enough to start the 70cc engine cold. You have to kick start it. Warm it is hit and miss as to whether it will start with the starter. The 50cc it is no problem to start it. I believe a pipe (which usually comes with variator weights and clutch springs) would probably give me an extra 5 to 6 MPH because it would allow the engine to spin up an additional 1000 to 2000 RPMs. For that reason, I believe the pipe is the best bang for the buck as far as getting extra speed on the Zuma. The stock carb/airbox seems to work just fine especially if you put an TK 84 main jet and bump the needle up a notch. The most reliable 70cc kits are the cast iron cylinder/2 ring piston kit. Mine is a Hoca and I am happy with it. Athena makes a good one for the money also. Polini and Malossi are probably the best but they are also $$$. I don't think I would mess with a carb unless you change out the crank. From what I understand, the stock crank is good for about 10K RPM which is what you can get out of a pipe. To get any faster, you will have problems pushing that stock crank to the 12K to 13K that will get you to 60+ mph. So bottom line IMHO is 1. Pipe to get top end. 2. 70cc Kit to get acceleration and torque. 3 Bigger Jet to keep from running too lean at higher RPM. Any of the other mods involve major changes to the engine/transmission that will make the bike less streetable and less reliable.
'84 Honda Aero 125
'05 Yamaha Zuma 50 (dual headlight mod)
'09 Yamaha Vino Classic (one of them new fangled 4 stroke things)

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