Recent Posts  By   (Read times)

What am I missing? All of a sudden my clutch is trying to engage at about 1000rpms. I thought it would be a simple fix and took my belt cover off to take a look. I saw nothing obvious so I took my variator and clutch off to look deeper.  I thought maybe a spring broke but all was ok. So I took the clutch apart to clean it and relube it and ended up dropping it and breaking one of the pullies. So, I bought a new clutch and installed it when it came in. I also cleaned my variator and made sure everything was ok there while it was apart. When I put it back together it is doing the same thing. Any thoughts?

There are a few mods I have done to my scoot. The first thing and the biggest thing is to get rid of the emission stuff. I disconnected the charcoal canister and got rid of the air box. There are some hoses you have to deal with when you do that. The crankcase vent hose has to have a pcv valve installed and then after the pcv valve, I installed a fuel filter to keep contaminates out. You also have to run the hose so the end of the hose is higher than the head of the engine to keep oil blow-by at a minimum. I ran mine up and at the back of the frame under the rear seat. Just make sure that all the vacuum hoses are hooked up that needs to be hooked up. You need manifold vacuum to your fuel pump and the valve on your carb. I installed a higher volume makuni fuel pump, better quality and better reliability. I have an egr valve on the exhaust pipe that is disconnected and the hose is just zip tied up out of the way and not blocked off. I disconnected the fuel tank vent because it got clogged up from filling my tank too high all the time. The fuel will run back into the vent hose and saturate the charcoal in the vent and cause it to plug up and then your scoot won't suck gas up because it causes a vacuum lock. I vented the gas cap by drilling an 1/8 hole in the top of the cap. Problem solved. I run a Uni style foam filter off of the end of the air box snorkel instead of right off the front of the carb. It seamed like it was getting too much air. When the filter was on the front of the carb, the exhaust sounded blatty, like it was too lean. With the filter on the end of the snorkel, the sound is deeper and seems to run the best that way. I opened up my oem muffler because I had a rattle in it. I discovered that there is a catalic converter in it and it had fallen off. So, I moded my muffler. I cut the cap off the exhaust end of the muffler and cut out the tail pipe. I enlarged the hole in the rear baffle to except a larger ID stainless tail pipe. The oem tail pipe is installed so it goes through the rear baffle and only MM from touching the next baffle. When I installed the new tail pipe, I made sure it just barley penetrated the rear baffle and welded it there. That would free up some restriction and deepen the sound of the muffle. Also, when I had the other end of the muffler open, I cut a section of the exhaust pipe out so the exhaust would not travel through the pipe route inside the muffler but instead, travel through the baffle hole straight out the back of the muffle. That frees up more restriction and makes the muffler a little louder. Not too loud. So now, the engine is a more efficient air pump. More air in, more air out. Now, at this point it will respond to rejetting like it should. I took out my oem roller weights in my variator and installed 20g slider weights. That causes my scooter to operate at a higher rpm letting it operate closer to it's optimum power output range. And there you have it.           

I went out and bought a new carb today. It looks a lot like my oem carb except it sais Japan on the side. I opened it up and checked the jets. It had a 108 main and a 37 pilot. I changed them to a 125 main and a 38 pilot. I also checked the needle valve. Mine on the oem carb was not adjustable. This new one is. It has 4 slots for the clip. It was set on the lowest slot. I changed it to the second to the top slot. I installed the carb and started it up. First thing I noticed is that the enricher worked like it is supposed to. Before, even after trying a new enricher, it would start up slow idle and idle faster as it warmed up. That would be wrong. Next, after it warmed up, I tried to adjust the mix screw. It also acted like it was supposed to. Before, my carb was unresponsive unless I screwed it out a bunch. I made all my adjustments and took it for a ride. It is stupid windy today. Earlier today when I was working on it with the old carb, I could only go 60mph and it was bucking and surging and would smooth out after I backed off the throttle. Now, it goes 70mph against the wind and no bucking or surging. The old carb was the problem. If anyone that has this same scooter and having these problems, get rid of that junk carb. Find a quality carb and enjoy the ride. I hope this post will save a lot of headaches for someone else.    

Well, funny you should ask. I'm having issues again. It was running good for a few days, and now it is back to surging again in the mid range. Again, it is loosing power under load ( heavy head winds ) and bogging down. If I back off the throttle, it will smooth back out. Acting like it is too lean. Eventually I will get to the bottom of this problem.

I got it all back together and didn't leave anything out of the carb. I did notice that there was rubber residue in the air mix screw but I don't see where it was blocking anything. So I started it up and let it get warm and started to adjust the carb. Again, I could close the screw all the way and wait and nothing happens. Idles perfect. I backed it out 1 3/4 turns and waited and nothing changed. I ran the rpms up and it surges a little between 4500 and 5500 rpm. So I started backing the screw out more and after about 3 turns it started to slow down. So, I turned it back in a 1/4 turn at a time until I achieved top rpm at idle and was running smooth. Ran the rpms up and no longer have the little surge between 4500 and 5500. I took it for a test drive and it runs out perfect for now. I'm going to drive it like this for a while and see how it does. Still don't seem right about the mix screw.   

Going to remove the carb again today and inspect it. Going to spray carb cleaner in all the orifices and see if anything is plugged. 

 Well, this is getting more interesting every day. I would like to know the start up and running characteristics of people who own these 250cc scooters with the 172mm engine. How does it act when you first start it? Idle slow then speed up after it warms up or the opposite? Any flat spots in the throttle response while cruising? Let me know. I would like to know how other scooters are behaving. After owning this thing for a year and I can't get anything to change as far as the way it runs, I am wondering if maybe I don't have a problem.