sixty4bitdiablo
03-10-2017, 12:01 AM
So my friend had a 150cc GY6 sitting under a tarp that had not been running in a couple of years. I was able to get it running after a new tank of gas, and installing a brand new 26mm carb. It fired right up, idled fine and ran decent on the road, however, it did accelerate a bit weak, especially at WOT.
SO, the plastics were destroyed and a lot of the parts to reassemble them were missing, so I ended up tossing a lot of the junk and going with a naked bike. With the installation of a slightly bigger carb, and the missing airbox parts, I ended up having a little pod air filter, and stock exhaust, and it ran good up until about 35 or 40 mph, where it would top out. Power was pretty weak the whole time, especially at WOT. I figured a rejet was in order because it was running lean.
The jet that was in the carb was not marked, so I threw in a 120 and figured I would adjust later depending on how it ran. Started fine, accelerated the same. Along the line I ended up putting in a new camshaft (a NIBBI 6.2 mm) adjusting valve lash, doing an oil change, gear oil change, replacing fuel lines and doing some new wiring work because some of it had dry rotted.
So, where I'm at now. Valve noise is definitely louder with the aftermarket camshaft installed, is this normal? I adjusted valve lash to .004 and .003 and it's still pretty loud. The bike still feels relatively weak at WOT, and now once it gets up to 30 or 35 mph, it surges significantly. It feels like it is bouncing off of a rev limiter. How can I fix this thing. I feel like it runs worse now than when I dug it out of a heap after sitting for 3 years.
I'm thinking it's still running lean, hence the surging at higher speeds/WOT and lack of power. Thoughts? Also, any way to quiet those valves down?
SO, the plastics were destroyed and a lot of the parts to reassemble them were missing, so I ended up tossing a lot of the junk and going with a naked bike. With the installation of a slightly bigger carb, and the missing airbox parts, I ended up having a little pod air filter, and stock exhaust, and it ran good up until about 35 or 40 mph, where it would top out. Power was pretty weak the whole time, especially at WOT. I figured a rejet was in order because it was running lean.
The jet that was in the carb was not marked, so I threw in a 120 and figured I would adjust later depending on how it ran. Started fine, accelerated the same. Along the line I ended up putting in a new camshaft (a NIBBI 6.2 mm) adjusting valve lash, doing an oil change, gear oil change, replacing fuel lines and doing some new wiring work because some of it had dry rotted.
So, where I'm at now. Valve noise is definitely louder with the aftermarket camshaft installed, is this normal? I adjusted valve lash to .004 and .003 and it's still pretty loud. The bike still feels relatively weak at WOT, and now once it gets up to 30 or 35 mph, it surges significantly. It feels like it is bouncing off of a rev limiter. How can I fix this thing. I feel like it runs worse now than when I dug it out of a heap after sitting for 3 years.
I'm thinking it's still running lean, hence the surging at higher speeds/WOT and lack of power. Thoughts? Also, any way to quiet those valves down?