Post by johnpainter on May 19, 2020 19:23:46 GMT -5
Long time motorcyclist, relatively new to Chinese scooters, though I’ve toyed around with a couple in the past.
I just purchased a 2013 Ice Bear Maddog (Chuckus) with GY6 49cc engine for $300, not running.
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The PO had tried to install a BBK 47cm but messed it up pretty good, it had no compression. He had put a rocker assembly with arms for 64mm valves on a top end with 69mm valves. The result was catastrophic, the whole rocker assembly was cracked in multiple locations and both rods bent. I replaced the assembly with correct sized arms and new rods, put it all back together.
The engine started right up, but died under throttle, I figured it had an air leak in the boot. It didn’t, I realized it had an oversized carb 24mm versus stock 19mm and was just gulping air. I happened to have a stock carb, put it on and it runs great, actually kind of surprised how smart for an 80cc the thing moves. It has the wrong size header, for a 150cc, for pipe. It starts and runs good, easily hits 35 in a short stretch in front of my house, and feels like it can go more before I’m WOT, I saw the plug was fairly dark so it must be running rich, I’ve got some jets and will see if I can tune the carb better.
I was not planning on keeping the scooter, was just going to fix and sell, but after riding it a bit it’s a fun rig so I’m planning on keeping it.
From the more experienced, with these scooters and Chinese engines, I need to know whether that over sized pipe is contributing to the rich condition and whether I should find the correct size header (the PO did some ok chop and weld so the header would clear the engine mount that’s on the bottom), or leave it be. Also if there’s other things I should pay attention to that’s particular for these scooters to make them run optimal.
I just purchased a 2013 Ice Bear Maddog (Chuckus) with GY6 49cc engine for $300, not running.
The PO had tried to install a BBK 47cm but messed it up pretty good, it had no compression. He had put a rocker assembly with arms for 64mm valves on a top end with 69mm valves. The result was catastrophic, the whole rocker assembly was cracked in multiple locations and both rods bent. I replaced the assembly with correct sized arms and new rods, put it all back together.
The engine started right up, but died under throttle, I figured it had an air leak in the boot. It didn’t, I realized it had an oversized carb 24mm versus stock 19mm and was just gulping air. I happened to have a stock carb, put it on and it runs great, actually kind of surprised how smart for an 80cc the thing moves. It has the wrong size header, for a 150cc, for pipe. It starts and runs good, easily hits 35 in a short stretch in front of my house, and feels like it can go more before I’m WOT, I saw the plug was fairly dark so it must be running rich, I’ve got some jets and will see if I can tune the carb better.
I was not planning on keeping the scooter, was just going to fix and sell, but after riding it a bit it’s a fun rig so I’m planning on keeping it.
From the more experienced, with these scooters and Chinese engines, I need to know whether that over sized pipe is contributing to the rich condition and whether I should find the correct size header (the PO did some ok chop and weld so the header would clear the engine mount that’s on the bottom), or leave it be. Also if there’s other things I should pay attention to that’s particular for these scooters to make them run optimal.
