New to me

[Rut Row]

Here's the deal with 2-strokes that a lot of people don't know: they run just as good backwards if you set the timing correctly.

Crappy old points ignitions could wear so they were firing close to TDC. Sometimes when starting, or running at very low RPM - like just before it stalls climbing a hill - the motor will switch direction.

This is real hard on the flywheel key.

IMHO, you'd do real well to adapt some type of electronic ignition to that motor -- they sell kits for small engines (go-kart racing) complete with rotors, sensors, and ignition modules.

http://www.msdpowersports.com/karts.html

they make those controllers for 2-smokes?

[Louge]

The points are shot, heavily pitted and blackened, which makes me wonder of the magneto spun on the crank a little throwing the timing off.

The points and condenser form a tuned LC tank circuit with the coil. If the points pit on the arm side you have too much capacitance, the ground side too little. If they exhibit normal wear your condenser is well matched ... don't change it. Conversely, if mismatched, don't be afraid to try different manufacturer's condensers, they're all very close in value, about .022uF.

We addressed weak ignition on a friend's Suzuki 250 2-smoker by installing a pair of Chevy coils under the tank. A stock Jap coil of that vintage puts out about 10KV at low RPM, about 4KV near redline. Good-ole junkyard Chevy coils put out 25 KV across the board. His pipes were soaking wet before the conversion, cigarette ash grey and dry thereafter. Be sure to get ones with internal ballast resistors.

I got to see this pedestrian 250 win against two TZ250s at Summit. Quite a happy day for my friend to stand on top of the box.

[CapoGreg]

I installed the new points, condensor, and crank key today. The spark tester gave a big bright flash when I kicked it over on the stand, noticeably better then before. I rolled it outside and poured some gas into the carb bowl, pulled the choke out and SUCCESS. It's still not running right, I have to leave the choke out and the head pipe nuts are loose, or else it stalls out on me. Next I guess I need to check the timing and adjust the carb to what the manual says.

Some sweet 2-stroke porn, although next time I need to turn the DAMN key on so I don't look like a jackass.
[youtubeurl][/youtubeurl]

[Rut Row]

Some sweet 2-stroke porn, although next time I need to turn the DAMN key on so I don't look like a jackass.

I thought those were primer kicks...

[CapoGreg]

Minor victory today. I disassembled the exhaust and cleaned everything with some starting fluid to cut the oil and carb cleaner to loosen everything else. I also put a couple old sockets I found inside and rattled them around to break anything big loose. It now starts with the exhaust bolts tight, however the donut at the engine was all but gone, so I need to add one of them to my next parts order.

Still need to have the choke pulled out for it to run, so I need to sort that out over the next couple evenings. Also, I was riding in the back yard and the clutch was slipping really bad, so I'm going to open up that side of the engine and see what's wrong there. It only has 4900 miles on it, so I'm hoping it's just out of adjustment, but I'm expecting the worst.

[Louge]

Still need to have the choke pulled out for it to run ...

Inspect the intake boot for cracks and the area under the pilot jet for jellified gas.

[CapoGreg]

Pulled the side cover off today exposing the clutch. It's in good shape, just well out of adjustment, I set it according to the manual, but we'll have to wait and see if I got it right. The gasket came apart when I opened it, so I need to get a new one. Should have added the entire gasket set to my last Dennis Kirk order

I also disassembled the carb too. It's very clean inside and I can see light through all the holes. I'm a bit puzzled though by what I thought was the choke. There's a small knob on the left hand side when sitting on the bike, when pushed in, it wouldn't run. When pulled out, it ran fine. I thought it was the choke butterfly, but there isn't one. Instead, it operates a plunger that open a port allowing air to bypass the venturi and go into the engine. So when it's out, it leans the mixture instead on enriching it. Given that, I would assume it's supposed to run in the "out" position. I've never seen anything like that before which is why I was confused.

Have any of you ever seen a carb like that?

[CapoGreg]

The side cover gasket is on order, should have it together Thursday. Now the the clutch is adjusted, it holds tight while I'm rolling the bike around. I don't want to start it with the primary and clutch dry. The new chain and sprockets went on fine, but the rear tire is a meaty MX tire and is rubbing a little on the swingarm and chain gaurd. Once the chain stretches a little it will be fine, but a 119 or 120 link chain probably would have been better.

Since nobody had any advice on the carb I'm going with my original thought process. I'll just run it with the plunger out to lean the mix. I reassembled it and put it back on the engine tonight. The fuel tank is soaking overnight to remove rust and etch the tank for the Kreem sealer that I hope to do tomorrow. Not much else right now, but hopefully it will be rideable by next weekend.

[Bucho]

Too bad you can't bring it to Granville's place tomorrow to ride.

[CapoGreg]

I wish I would have had it done for that, but I've never ridden single track so I probably don't belong there anyway. I hope to make it to Greenridge next month, but I also have Blue Collar Comedy tickets for that Saturday night so I'd have to leave early.