What should you pay for a Yamaha QT50

I’m looking at a QT50 that I’m thinking about buying. What should I look for?

1. Take a flashlight and take the lid off the gas tank. Shine the light into the gas tank and determine how rusty the inside of the tank is. Chances are you still won’t get a good idea of how rusty the tank is even by doing this. Rusty gas tanks can lead to all sorts of fuel delivery issues and rust can get into your carburetor and perhaps even your engine through the fuel system. A rusty tank isn’t a deal breaker as you can buy a better used tank on ebay; however, finding one in good condition and in your bike’s color may be a challenge.

Rusty tanks can also be cleaned up and made to work. Several methods are outlined here at mopedarmy.com. I’ve used the vinegar and salt method but now mainly use EvapoRust.

2. If the bike doesn’t run, make sure you can push down the kick start with ease. You can also get an idea as to its compression by using the kick start. Take out the spark plug and shine a light into the cylinder and get an idea of the condition of the top of the piston. Next, hold a finger over the spark plug hole and have a friend kick start the bike. If your finger is forced off, the bike may have decent compression.

3. If the bike does run, take it for a test ride. If it will do its top speed of 29-30 mph, you’re in luck. If it goes slower than this, negotiate accordingly.

4. If the bike pulls to one side while riding, it may have bent forks. Also check the foot pegs to see if they are bent. Turn signals and mirrors are also casualties of past wrecks.

5. Check and see if all the lights and horn work.

6. See if the side covers are still installed. These are usually the first things that are misplaced.

7. People often screw up the wiring. Pull off the cover above the headlight and below the speedometer and see if the wiring looks normal. Pull off the battery cover and check out the wiring in the back as well.

8. Unfortunately, it’s fairly common for people to lose the key. This leads to hacking into the wiring. It also leads to using a key other than the Yamahopper one. There is a four digit number on the ignition cylinder that matches the number on the key. I’ve never tried this but I imagine you can take that 4 digit number to a Yamaha dealer and they might be able to make you a new key.

9. Does the owner have title? Almost all states require title to obtain license plates and registration. This is not a moped since it doesn’t have pedals. It is considered a motorcycle by most states.

10. Check out the exterior of the carburetor. If it is a complete mess, chances are the inside isn’t much better.

With all this in mind, what should you pay for a Yamaha qt50?

Prices vary throughout the country. If it passes all the tests above, is in mint condition, and has title, I wouldn’t pay more than $650. If it doesn’t pass all the tests, subtract as follows:

Very rusty gas tank requiring replacement – $100 deduction;
If the bike doesn’t run – don’t pay more than $150;
For every 1 mph below top speed of 30 mph, subtract $15-20;
Bent forks such that it pulls hard to one side when riding – subtract $85;
Headlight doesn’t work – subtract $45;
No side covers and you really want them – subtract $125;
Wiring issues – subtract $100;
No title – subtract $150-$250 (although you can register and get plates through Vermont so lack of title may not be so important);
Carb needs replaced – subtract $35;
dead battery – subtract $25;
seat is beat up – subtract $40;
Needs both tires – subtract – $95;
Air filter missing – subtract $35.