Recent Posts  By   (Read times)

For me, it's 1/3 fun, 1/3 necessity*, and 1/3 teaching my self something new.

*When I was looking for a tach for my scooter, I had searched all over the internet for a smallish tach for motorcycles, ATVs, snowmobiles, and the like that wasn't digital and would work with a 4-stroke engine with wasted spark ignition (one spark per revolution) for under $50. The only one that I could find was the chrome one that I took apart on the previous page.

I had the tach that I took apart previously hooked up to my scooter, and it worked like it should (meaning when the engine was turning at 5000 rpm, the tach would show about 5000 rpm), but the response time was very poor (if I revved the engine from idle to WOT, the tachometer couldn't keep up with the change in rpms, it would be showing 3500 when the engine was turning 7000).

I really wanted an analog tachometer, but this one just wasn't cutting it. I had dabbled very lightly in arduino-type stuff previously and thought that I could, with enough time, information, and headache medicine, make my own tachometer plus a small array of information displays like voltage, oil temp, and speed.

So far, I've got a servo to move; reflecting a measured rpm signal (on the previous page). That was pretty easy compared to what I have been doing over the last few days - using a stepper motor instead of a servo. Over the last 5 or so days, I've got the stepper motor to sweep back and forth hitting both end stops and setting itself up at the initial starting position.

That might not seem like a lot to get done in 5 days, but I do have ADD, so I can only work at programming for a couple hours at a time before my brain refuses to stay focused for more than 5 seconds. Also, I am learning the arduino coding language (which, as I understand it, is a modified C language) as I go, so I am constantly looking up how to do certain things and if other people have done similar things to what I am doing.

I got another carb for my Lance Duke 250.  The idle mixture screw had frozen in my old one.  The new carb (from China) didn't even have a brand name or model number on the body, but it works fine except that it runs lean according to the plug.

I took the needle up one slot, but still not enough.  Only one slot left which will be taken up today.  I do like that it will start and idle cold almost immediately, unlike than the old carb.  Never the less, it seems to run hotter.

I checked the main jet which is the same size as the old carb, a #110.  I think I'm gonna need a bigger jet.  Are larger jet numbers bigger or smaller?

It occurred to me that overheating problems I'm having and that I am reading about here may be due to a change in gasoline to include some ethanol, which mixture if I remember correctly, burns hotter.  I think the mixture here in California is 10% ethanol, but don't quote me on that.  It would also explain my idle mixture screw freezing.

If ethenol is the problem there may be a run on bigger jets before this is all over.

So from a #110 jet, which is a larger jet, a #108 or a #115?

Great so the wheel is not binding so then I would say that muffler is throwing a lot of heat onto the rim and tire.
Alleyoop

What I would do is check the rear tire for binding, So put it on the center stand and with your hands spin the rear tire. If there is binding it will be hard to spin then check the brake if not then I would suspect the bearing is binding.
Alleyoop

I would go one step further......I think that motor may be running lean. You should be able to hold your hand an inch from the pipe. Also would think about shimming the pipe out a bit too.