New to scooter engines, Florida By rw0575 (Read 982 times)

[rw0575]

New to scooters, although I am pretty good with auto mechanics. I've never worked on a small gas engine and I'm guessing they should be easier than a large automobile engine.

I just purchased a 2000 Yamaha Riva Razz 50cc scooter (model SH50) to use around town and have noticed some issues even before I could print out the manual.

It is only getting 40mpg, the engine seems excessively loud, there is bluish smoke, it only goes to max 30mph and not the 40 I expected it to, and the other day the electric starter button stopped working. The same day I had to use the kick start instead of the button, it started with the back wheel wanting to constantly rotate so I have to keep the hand break on at all times. It didn't do this when I had practiced kick starting it before, at least not that I could remember.

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[cruiser]

Welcome to the forum, rw0575. Your scoot uses a detuned version of the Yamaha 50cc 2 strokes. It sounds like the pump for the oil injection might need attention and/or the carb might have issues. Sounds like an over rich running condition might be fouling the plug which would hurt performance and fuel mileage.

Performance enhancements might be difficult as the scoot uses a single speed transmission instead of a CVT. 30 mph is about right for this scoot. Maybe some of our 2 stroke riders might be able to give some suggestions. Here's the service manual:

.motorscooterguide.net/Yamaha/Razz/Razz.html" rel="nofollow" target="_blank">.motorscooterguide.net/Yamaha/Razz/Razz.html

[JR]

Welcome to the forum. We also have that manual in the Yamaha section:

thescooterprofessor.proboards.com/index.cgi?board=ncmanuals&action=display&thread=265

Page 130 for the wiring diagram on the starting system and from what I see it's just about the same as standard Chinese scooters are. The starting relay is tied in with the brake system and the start button completes the ground side of the circuit when pushed.

Did this no start thing just happen or has it been doing this for a spell.

JR

[alleyoop]

Welcome to the forum, good to have you here and yes 30mph is about it for that scoot. Some were even restricted to go only around 25mph, so you have one of the faster ones that they made. What year is it the last year they made those was 2001.
Alleyoop

[rw0575]

I just purchased this scooter then second week of October. It seemed okay with no problems until I rode it for 20 miles (small distances and short trips added together). It turns out the carburetor wasn't seated correctly. I had a shop fix that issue and I've changed the idle speed (It wasn't staying on after I got it back and it was the low idle speed). Thank you for the manual. I need to get it printed so I can take it outside to the bike.

It is still having stalling problems. It usually starts okay, not great, but okay. After I ride it for about 5-10 miles, then it sits for about an hour, it doesn't want to start with the button, and doesn't really want to start with a kick start. Once it does, it goes for a few feet, then stalls out. Once I get it going after a few tries, it still kind of chugs. What I mean by chug is it feels like the gas isn't going anywhere sometimes...it loses power. Sometimes it just flat out dies in the middle of the road while driving it.

I'll check the plug even though the mechanic said he did that. I'll ask the mechanic if he checked the oil system like I asked.

I don't understand why it is more expensive at all the bike repair places than at car repair places. I've called all the shops I could find and even some of the stores.

The 2-stroke oil seems to disappear really fast. Is that normal? Is it something you fill up and use like your gas, not like say brake fluid, transmission fluid, or steering fluid in a car? Thanks for all your help.

[rw0575]

I need something to go more than 30mph, even just up to 35-40 is really all I need. It's my only mode of transportation and the roads around here have 35-45 mph and everyone speeds. I'm wondering what kind of scooter I should have purchased. I thought going with a Yamaha or a Honda would be a great bet. What 50cc scooters have speed up to 35-40 for a 50cc? I'm thinking I need to sell this because of the speed regulation issue if I can locate a better one after I get it fixed. Does anyone have any good recommendations for a 50cc that would go 35-40? I would need to buy a used one for my budget and my . Especially if this one isn't sold first. Thanks!

[terrilee]

i am NOT a mech
just a rider for many years
so, lmsao, i guess im a part time mech

the only topic im gonna address is the speeds you wanna go.
your 50cc wont do those speeds for very long,
w/o dying.
you should up grade to a 150cc.
most of those will cruise at LEAST 45 all day long
mine will cruise at 55 all day long,
with a top speed of 67 mph and that isnt even WOT,
BUT i have one of the better made China Scoots.
and she's still all stock.

listen to the guys on here
they wont BS ya, and will help you fix any prob.

oh another thing i'll say
YES shops charge crazy prices
thats why most of us do prevent maint.
and do ALL our own work.
im a old woman and have learned alot on here and other forums
have NO problem attempting to do all my own work.
My big prob, is i dont have a shop with a ton of tools, sooooooo

GOOD LUCK

[alleyoop]

I agree if the speed limits on most streets around you are 35-45 you really need a 150cc scoot. If your going to be taveling on those streets you need to be able to keep up with traffic. Now you know if the speed limit is 35 the cars are doing 40-45 mph, it is 45mph the cars are doing 50-55mph. So you really need a 150 to be safe traveling on those streets so cars are not trying to get around you.
Alleyoop

[rw0575]

Thank you. I know car mechanics pretty darn well. I need to get over the fear that I'll do something wrong. I just checked the spark plug. Either the guy ripped me off or he didn't do all of what he said. I should have known something was up when he said he did the tune up I asked for along with dealing with the problems he found and the 2-stroke oil wasn't even filled. I suppose I thought maybe tuneups for bikes weren't the same as a car tuneup regarding filling fluids. He either didn't replace the spark plug like he said or he replaced it after the carburetor and the air/fuel mix was adjusted. I've got a list to talk to him tomorrow (mostly because if I already paid him to do something, he should remedy the situation. I really need this thing to not stall. I wish the manual had more pictures. It took me a couple of minutes to find the spark plug because it didn't really tell you where it was.

[alleyoop]

That is a shame rw0575, most of these shops just want to rip people off especially if someone comes in and doesn't know anything about the scoot. They also are sloppy and do NOT reconnect things back up and or leave screws off if they had to take plastics off. They just know how to replace parts and do not know SQUAT about how to go about and tune a scoot motor and or diagnose a problem.

If you can take a picture of the CARB which I believe is a SLIDER TYPE the THROTTLE CABLE is going into the top of the carb. It may have up to THREE SCREWS on the LEFT SIDE.

If the OIL LINE IS GOING TO THE SIDE OF THE CARB it may have a SCREW to ADJUST the AMOUNT of OIL it drips into the CARB to mix with the fuel.

On the LEFT SIDE there should be TWO SCREWS on the CARB as you look at it.
ONE SCREW will be in the MIDDLE OF THE CARB(THAT SCREW is your IDLE ADJUSTMENT SCREW)
If you turn that SCREW Clockwise it will RAISE the IDLE and Counter Clockwise will LOWER your IDLE. Now the IDLE SHOULD NOT be so high that YOUR REAR WHEEL IS SPINNING. YOU Want the IDLE to be just high enough that the REAR WHEEL may want to turn.


NOW I SAID YOU SHOULD SEE 2 SCREWS:

Now looking at it from the side IF THERE is a SCREW to the RIGHT of the CENTER IDLE SCREW that is a AIR RATIO MIXTURE SCREW. IF the SCREW is to the LEFT of the CENTER IDLE SCREW
that is a FUEL RATIO MIXTURE SCREW.

On yours I would think the Screw is to the RIGHT(AIR RATIO SCREW).
Turning that CLOCKWISE Cuts off AIR and therefore MORE FUEL is fed to the motor.
Turning that COUNTER CLOCKWISE Allows more AIR and therefore LESS FUEL is fed to the motor.

Now How to ADJUST the AIR TO FUEL MIXTURE:

Start the SCOOT and let it WARM UP about 5 minutes:

NOW WHAT YOU WANT FROM ADJUSTING THE SCREW IS TO GET THE HIGHEST IDLE POSSIBLE:
SO LISTEN VERY CAREFULLY on how the MOTOR RESPONDS as you adjust.

SO now that the motor is nice and warm:

1. Turn the AIR RATIO SCREW the one near the AIR FILTER 1/8 CLOCKWISE and wait about 10 seconds to allow the motor to adjust to the new setting:
a. IF the IDLE GOES UP REPEAT 1 UNTIL nothing happens THEN TURN IT COUNTER CLOCKWISE half of the last 1/8 turn you did--GO TO #3.
b. IF the IDLE GOES DOWN on the FIRST 1/8 or does nothing Turn it 1/8 back and GO TO #2.

2. Turn the AIR RATIO SCREW 1/8 COUNTER CLOCKWISE and wait about 10 seconds to allow the motor to adjust to the new setting:
a. IF the IDLE GOES UP REPEAT 2 UNTIL nothing happens THEN TURN IT CLOCKWISE half of the last 1/8 turn you did--GO TO #3.
b. IF the IDLE GOES DOWN on the FIRST 1/8 or does nothing Turn it 1/8 back and GO TO #3.

3. Now that hopefully the mixture is good THE IDLE MAY BE TO HIGH and the REAR WHEEL is spinning. If the REAR wheel is spinning TURN the MIDDLE SCREW(IDLE SPEED SCREW) Counter Clockwise a little like 1/16 of an INCH put the brake on and see if it starts to spin.
a. If it still spins REPEAT 3 until the rear wheel JUST WANTS TO TURN--GO TO #4.

4. Give the Throttle a quick twist and let go, HOPEFULLY it should rev up good no bogging and hesistation and return back down to IDLE.
Let me know how it goes and if you can take pictures of the CARB that would be great.
Alleyoop

[rw0575]

Alleyoop, Those are some of the best written directions I've ever seen. I'm impressed, few people have that skill. I worked on it more today. I'll have to print off these directions and do this in the daytime. Thank you!

[alleyoop]

Thank you for the kudos, and do not worry we will guide you through everything. If you do not mind getting your finger nails dirty you will be our eyes and hands and we will get that puppy rocking and rolling.
On somethings pictures from your side would help a lot so we can see what the scoot has or does not have. Some have different emissions and different emission setups and some do not have any at all then again some come with up to 3 Emission setups, PAIR System, EGR System and an EVAP System.
Alleyoop

[rw0575]

I will try to figure out how to post the pictures. Right now I'm trying to figure out why it won't even turn over. I've taken it to the mechanic almost a dozen times to fix the same problem. They finally replaced the spark plug yesterday, said they cleaned out the carb again. Am I missing something on how to properly start the engine? Am I suppose to prime it somehow? It just won't turn over. It seems like there isn't gas getting to the engine to turn it over. I'm about to pull my hair out right now considering this is my only mode of transportation besides my feet.

[alleyoop]

When you say won't turn over, do you mean the motor cranking but will not start OR do you mean nothing happens when you hit the start button. I would tend to guess since most say that it will not turn over "MEANING" the motor is turning over but it will not start. Sure sounds like the carb needs some adjustment.

You can us PUSH a PICTURE and just copy your picture link and paste it withing the Push picture url.
PUSH A PICTURE

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