The Cochino

by Daniel Gutierrez
Added: • Updated:


1979 Yamaha QT50. My first bike. Downloaded a owners manual and a shop manual for free. Highly recommended. Made mine into a book and comes in handy when doing repairs. I live in California so it has to be registered as a motorcycle. License and insurance required. Most of my parts are from Treatland, Myrons Mopeds and various sources on the web. Blew my 50cc right away.. Wack! Oil pump failure. Used the opportunity to upgrade to a 60cc. First one I bought I spent about $85.00. After blowing 4 piston kits. I started just getting the least expensive ones I can find and they work fine. I went through so many kits. When installing piston I was installing upside down. Remember arrow down towards exhaust. When installed the other way the ring openings hit the exhaust port opening causing failure. I was lucky that the manufactures replaced two of them as defects. Woo Hoo! Regardless lesson learned. Removed oil pump, and plugged with an overpriced plug from TL. Used the oil tank reserve to hold more gas giving me I believe .8 of a gallon. using gps I tracked about 45 miles to .8 of a gallon. I left the oil pump sensor in. Makes a good plug, but cut the wires. Something about having power in a spot that now has gas. Just saying. Upgraded carburetor. Went to a Mukini 18mm carb with a 18mm MLM intake to match. 18mm carb because you can only find an 18mm intake for the QT. You can get the 18mm intake and put a 15mm carb by removing the spacer to get better gas mileage. I chose power over mileage. If you're not going to upgrade intake I don't recommend upgrading carb. Whatever you get will still be feed into a 12mm stock intake. Better to match for maxium power. Replaced reeds to Boyseen Duel Stage Reeds. Can't tell you the difference, but feeling better knowing its upgraded. Purchased 40/042 hex jets ranging from 50-90. After many attempts to figure out right jetting ended up with 85 jet, 1 1/2 turns on the air screw, and the needle clip at the top. NGK spark plug BP7HS. Still might jet it to a 80, but have to make sure I won't run too hot. Gutted the exhaust and ran like a champ, but was seizing my engine couldn't understand. Down hill, high speeds would just shut off. Friend of mine suggested I was over gearing. Looked on line an found people changing to pw50 gears. Found if I changed it, it would give you a lower gear ratio and better top end speed. I lucked out and found one for $60.00. Replaced it as well as lubed the gears since I was there and also changed the bearings using a special tool and help from you tube. Problem solved can blast it and run my bike hard. With the help from a fellow Lord ( of the LandLords) he made a cross bar for my bike. first try and it fit perfectly. Really helps in the overall support of the frame preventing bending and twisting of the frame while riding. Took away the rack in the back and made a bracket for the backlight. Changed the headlight and removed the speedometer and cable. Found a shock that I installed using brackets. air filter I bought off geek for $5.00. Just recently purchased the MLM peoples pipe. really didn't want to spend $200.00. In buying it i have to say I'm glad its over and don't have to buy it again. lol. Don't like the bend it was given. Bottomed out with a big dent the first day With all the upgrades before MLM pipe bike ran like a champ. Had awesome torque very punchy almost falling off a few times. Top speed was good hitting about 35mph. Installing the pipe gave it a big boost in power and overall top speed clocking 42-45mph. Lost my torque in low end, but it a fair trade off for top speed. LANDLORDS M/G


1979 Yamaha QT50




Sign in or Create an Account to post a comment.