Howdy! I recently purchased a GS500F that wasn't regularly serviced or maintained. From the start I new I would replace all the basics like air filter, plugs, oil. I've worked extensively on multiple scooters in my day but this bike is my first real motorcycle. So to the problem:
I disassembled the carb for a deep clean as it continued to bog out on me at higher speeds and eventually refused to start up. Cleaned everything thoroughly with carb clean and cleared all passages with guitar string. I checked the diaphragm to ensure there were no tears or holes. The needles and jets were in tact. After reassembling the carb and reinstalling it, voila, the bikes starts right up. The idle is smooth the engine warms up quickly. The problem seems to be when in any of the 6 gears, my top end acceleration after 5-6K rpms is dramatically weaker. Im not sure what is responsible for the lack of power because it was not like this before I took apart the carb.
Basically, I screwed up when reassembling the carb. Im almost guaranteed that I put the jets back in the correct position because I drew a diagram when removing them. I think my problem lies either in the float needle hanging on the bracket backwards, crap in the float needle seat, or the float being to high. Any suggestions or information would be useful! THANKS
Stock intake & exhaust? And have you checked the valve clearances yet?
Weak after 5k usually is rich on needle, floats and maybe mains.
The order of likely culprits are exactly that, needle, then float then mains.
Setup and jetting is relevant though like Rich was asking.
BTW your air filter clean ???
Cool.
Buddha.
Yes the bike is completely stock. I have not checked the valve clearance yet - I will most likely get to that in the coming weekends.
As for now, I did not have this problem just before I removed and took apart the carb. Which is why I dont believe the valve clearance is the cause of my current issue. What should I be checking for with the needle? I didn't even remove it from the diaphragm slide so I didn't adjust the height or lose a clip when taking apart the carb. Thanks for the responses guys!
Oh - what about fuel starvation? Clogged tank vent, carb breather hoses, low float height, etc.
Sorry for the delayed response guys. I was able to open up the carb and realized the problem was right in front of my face. I don't understand how I missed it after rebuilding the carb twice but I managed to pinch the slide diaphragm both times. One of the carbs had no vacuum at all which was the source of my problem. Boom, problem solved.
However, a week or so later the bike does not want to start up unless I put the petcock switch on PRI. Once the bike is warm I can switch it back to ON but otherwise the engine sounds like its not receiving fuel. Definitely a vacuum problem from the petcock or even fuel tank to the carb. Where should I begin looking? Im new to the whole petcock troubleshoot so I would be wasting a lot of time just searching for an issue. Any help?