I have been working on this ds90 for a few weeks now on and off. I have cleaned the carb multiple times but i cant get it to take off. It bogs down and will die if i dont let off the gas when trying to go passed half throttle. It has sit for a few years before i purchased. I have removed the screen from the muffler, replaced spark plug, new gas and oil.
It doesnt have an air filter but still has the air box. I have tried moving the e clip on the needle up and down a notch but i still get the same results. I have tried with the wheels off the ground also but still bogs. Im not sure what i should do. My son is getting frustrated because i havent gotten him riding yet.
It will idle and start great with the air box off but will not go passed half throttle. If i put the air box on it becomes hard to start and will still idle with throttle but will bog the same. Im assuming im missing something simple. Im guessing some general guidelines on air/fuel screw setting would help but any HELP will get me back to super dad status. I havent checked the reed valve but i have check the exhaust to make sure it was clear from the cylinder to the end.
Thanks
if it sat for a few years take off the pipe and make sure mice didn't build a nest down inside.also,put the quad on stands and run it to see what it does.from the sounds of it your pilot jet might be gummed up.did you drain the tank and put fresh fuel in?
Yea i drained the tank and put new gas in. I have had the pilot jet out and it is clear. The pipe i completely removed it and visually checked it and blew air through. Seemed clear. There was an air port on the front of the carb that was stopped completely up. This would be the end were the air filter or air box would mount. I have attached a pic with the port circled. I was unsure without looking at our carb again which one exactly was stopped up. I did clear it but i was afraid it is stopped up inside were i cant see. I was going to buy a new carb but wanted some good advice from you guys before i did.
if you put the stock airbox on it bogs?? hmmmmm did you try an aftermarket filter? try cleaning the stock filter? I would definitely take the carb completely apart and soak it overnight in purple power/simple green or a few hours in carb cleaner this way you know for sure.how about your fuel filter? did you replace it? also,use compressed air to clean out the carb ports. do you still have the stock fuel shutoff? try running a line directly from the tank to the carb and see what happens.i've had a shutoff go bad and we chased that problem for awhile.do you still have the stock electric choke? is the stock carb a sunworld?
Yea it bogs and seems to run worse with the air box attached. I havent tried an aftermarket filter yet. I will take the carb apart and soak it over night. I will let you know if it helps. I have replaced the fuel filter. I will try running a direct line also. It still has the electric choke. It has a mikuni carb.
our old Polaris(06 90cc)had an electric choke and I yanked that carb for one that had a manual choke and it was much better.it was a 24mm keihin.do you have another carb to try or maybe borrow one? just out of curiousity,take the fuel line off the carb and then open the shutoff and see if you get a nice fuel flow.
Check the basics first: compression, clean fuel, plug gap ( incorrect plug gap will definitely cause a bog a WOT)
Then
Try putting your filter back in (the bike should run like garbage with the filter removed) , install a new plug (check the plug gap) turn your air screw all the way in then back it out 1-1/2 turns. Start it up, let it get warm turn your air screw in and out 1/2, or 1/4 turn at a time waiting 15-20 seconds between turns. You are tying to get the bike to idle at the highest RPM. If it idles highest less than 1 turn out you need a larger pilot jet, if it is more than 2-1/2 out you need a smaller pilot jet. Once you have this set, then work on your needle if it is still bogging.
Also, check in the DRR, Apex forums for info. They are the same exact motor.
Thanks for the help guys. I will check into all this. Today was mothers day so i had to spend time with the wife and my mother. I will try to check all this tomorrow evening. I do have another carb on our ds50 that runs fine. I just figured it was jetted differently due to the engine size.
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