Minarelli 2T rings

[duosport]

:stumped: I read you can put your exhaust on a white hot bed of coals and heat it up and burn off the internal carbon build up. I cannot make such a fire where I live. I have removed the heat shield and muffler from my exhaust system and placed it on my propane grill. I had removed the grates from the grill and set the exhaust directly on the burn pipes of the grill. I have been heating it up for about 40 minutes now. I do not think it will get nearly hot enough to burn off any deposits though I do see a bit of smoke comming out of the end. Maybe it is doing something.

[duosport]

OK so I also attempted to run carb cleaner into the exhaust pipe I did not see much help in that. Frankly after I removed the muffler part of the system there was no restriction in airflow. I then rode it with just the pipe on and no muffler. It ran even better than with no exhaust. Now I am getting about 31 mph on the flat and getting there in decent time. My 4t is still faster by a long shot but the 2t is getting closer to a more normal operating speed. So I attempted to clean the muffler portion. I then realized there was a very narrow opening in the exhaust end of the muffler. It was a little cruded up so I scraped it clean. The opening would seem to be a restrictor. It is only something like a quarter of an inch in diameter. When I put the clean muffler on it shot down my performance a lot. Though after cleaning it was better than before. I think I should drill out the small hole in the end of the muffler.

[duosport]

So now I am wondering about the belt. The one I put on along with the new rollers hurt my performance rather than help. I think I will put the old belt back on and see how it is with the new rollers and the muffler off.

[duosport]

So I disassemble the variator to replace the new belt with the old one and then something hits me. There is no collar between the variator sheave and the fixed sheave. I looked where I worked last night and there it is. I forgot to put it in place. How stupid.

[90GTVert]

On top of the other stuff you've discovered, I'd drill out that hole. No exhaust inlet or outlet should be only 1/4".

[duosport]

I drilled it out to 7/16ths and drilled two small holes agacent to it at 3/16ths. There is a cap at the end that fits over all with a gasket. So combined these three holes should equal the pipe size.

[duosport]

I am messing with the carb now. I have taken apart the cable needle assembly. I had not done that before. I have moved the catch on the needle from the top to the middle position. I put it all back together. It sounds a little meaner. My take off from start is pretty good now. Better than my 4 t. 0-20 is pretty quick. Then after that it is a dog. So I guess that says something about the roller weights huh? The top end improved from 32 to 33 mph. not much but still.

[2strokd]

You dont have a tachometer do you?
Might try different weights? Do you have a cam to make a vid?
A run down the street with the cam at a fixed point might help us help you?
At least you learning allot more about your scooter! Thumbs up man! Great job!

[duosport]

No tach, no cam.

[duosport]

So the width of my old belt and the width of the new belt are identical. The circumference of the new belt is larger. If my goal is more top end, then the new larger circumference belt should be the better one right? Also I am gathering that if I were to remove the washer adgacent to the sleeve between the sheaves, that I would increase top end maybe too? I am guessing that with the space narrower, the belt would ride higher and that would be like a taller gear. Do I have that right?

[90GTVert]

You've got those right. Now, if the belt is too long it could slip off. A belt of the proper length will usually sit all the way outward on the rear pulley and all the way inward (assuming there is enough room) on the front pulley at rest. Ideally it would be just the opposite at top speed.

[duosport]

when I measured my old belt before Idid it with inches and used a converter for metric. I made a mistake in it. I said before my belt was narrower than it really was. The real width of the old belt and the new is 5/8" which is 18mm. Now the old belt has worn to that dimension. So I can test the old belt with the new rollers but if I have top end issues a smaller circumference is not going to help me. My best bet sounds like to narrow the distance between the sheaves with the larger circumerfence belt. (as long as it stays oin the pulleys)

[duosport]

After taking out the washer and then adjusting the carb mixer I have it topping out on the flat at 36mph. Still not great but good enough to take on the road a bit. I was just thinking about it, that I just did a ring job on this scooter. Even though it was over a month ago I have not hardly ridden on it yet. So I put all of the plastics in place cleaned it up real well and took it for a spin. Though it is not really fast enough what a joy it is on the road. The ride, the handeling are great. I just need to milk a few more miles out of her and she is my new main scooter....well at least till I get a 150cc.

[duosport]

I am still going to drill that muffler hole wider though. I think that is still holding it back.

[duosport]

The weekend approaches and that is the time for me to work on my scoot. It may be running but it is not running fast enough. Something or things are still amiss. What do I do next? My guess is I need to establish where my belt is actually riding on the vari. Is it optimal? Probably not. I am planning on taking the muffler end part of my exhaust off and seeing if I have improvement, If so the whole I drilled is not big enough I am thinking. I have a 50cc chinese 4stroke engine sitting in the garage. Not sure what rollers ar in the vari. If they are the correct size and heavier maybe I could try them.