Scooter slower after air filter upgrade By gross392 (Read 2,940 times)

[gross392]

Hey guys, the new guy here from Mn, I have a Xingyue 150t and I just put a foam air filter in from scrappydogscooters and I also went with the 115 jet. I have it running real solid and the plug looks really good, but I have a question. Is there any reason my top speed would go down by a couple MPH at all? I remember being able to get to at least 60MPH in the chinomter and now it seems like i'm topping out at like 57 MHP.
I'm not looking to gain a bunch of power I just did it mostly because I was going to rejet anyway and figured might as well do an air filter as well. It also sounds a lot better than the stock air filter...
Thanks for your input!

[gross392]

I willl give it a try. Does the tube give it more air rather than just hooking it straight up to the carb? Currently it is straight on the carb...

[gross392]

I'll run to the hardware store tomorrow and grab som radiator hosing that will fit and see if we can get more speed...

[gross392]

not necessarily more, just back to normal...but more wouldn't hurt either i guess

[gross392]

Ok I tried a couple different "velocity stacks" and brought my needle up about one notch. Since my needle on this scooter isn't adjustable i just used some really really small washers haha. I used 2 to raise it...

First one I tried was a radiatior hose and it had a bend in it. It was a little more naroow than i would have liked. Got it all rigged up and sounded good on the center stand and when I thought it was in the ballbark of a/f mixtuer I went to ride it and you could tell the main jet was a bit too rich. It would bog after about 20MPH, but ran great up till then. I would let off the gas and it would stay around 20 MPH and not surge ahead, telling me rich. I fiddled around and finally said screw it i'll try the other pipe.

Pipe two was a rubber necking or whatever you call it. I think it's mean to connect two pvc pipes or something. I tested it's heat capacity by holding a lighter to it to see how easily it would melt, it didn't hardly give so i think it will work fine. The pipe is kind of an adapter going from about 2" to 1.5". The 1.5" matched up perfectly over the carb and made a really good seal and the 2" side went over the air filter and it was a tight squeeze. Since the adapter went over the air filter, I took the ring, used to tight the air filter usually, off and tightened the adapter to the filter. Once tightened I check inside to make sure there were no kinks or anything. I left the needle the same setting and adjust the a/f mixture till i thought it was good. My speed is back up to 62 indicated which is a touch more than I had before.

I took it on about a 10 mile run and have been checking the plug and it looks a lot better now. I took some picture but can't figure out how to post them haha. Before when it was hooked up right to the carb, the base of the plug where the threads start was kind of black now it is a more brownish color. Overall it is running pretty smooth throughout all throttle positions. I will try to post these picture on a photo bucket or something...

Thanks JR, so far so good. I think i'll leave good enough alone until this longer belt gets in

[kiwiscoot]

I see you have a Xingyue XY150T. On my wifes one I drilled 3X 8mm holes in the back of the exhaust to make it more free flow. I drilled them between the small outlet pipe and the ring that is around the little outlet pipe. You need a long drill (12cm) as the back of the exhaust has a dead spot with double plates at the back. You need to drill thru the inner back plate else the holes do nothing. Gives the scoot a nice deep sound too, but it isn't noisy. I noticed a difference in performance. The little exhaust outlet look just to small, not even the same size as the exhaust from the engine.