Removed The 2nd Restrictor From My Leo Vince ZX

[stepthrutuner]

Also, my tach is better but still not 100%. It still wants to go into set-up mode sometimes. I may have to get a new one sometime.

[90GTVert]

My gaskets came in from A&J parts, so I got to work on my cylinder porting project tonight.

As soon as I pulled the cylinder head, it was obvious that this was going to be a cleanup project and not just a little port raisin'. I think I know why I was getting spark knock again!



A little bit of time with some steel/brass bristled brushes did the trick.



Now on to the cylinder. It doesn't look any better. You can see that there is a little scuffing and a lot of carbon. The scuffing isn't as bad as I expected really. ive put this thing through a lot, especially while trying to get it all sorted out and siezing it up a few times. Also not bad for 50:1 premix.



I cleaned out the buildup, then raised the openeing of the exhaust port 1-1.5mm. I opened up the outlet just a little to match up to the pipe slightly better and smoothed the port a bit. I chamfered the edges of my port work, then got out my handy dandy 54mm ball hone. I've been itching to use it, and now seemed like a good time. It did a great job of chamferring the ports even smoother and it knocked out the ridge at the top of the cylinder. 30 seconds with a ball hone and some PB Blaster does wonders.








So... did it work? The first thing I noticed when I fired it up was a very low idle (which I was too lazy to fix after getting cleaned up and being late). The next thing I noticed was that my exhaust and intake were both louder. Now the 2 stroke "ting" is more noticeable. I hopped on and I could tell something was different as soon as I got on the throttle out of my driveway. The low end may be slightly weaker than before, but not much. Midrange and upper RPM power has improved. I think it pulls just a little higher RPM now, but not a lot. It has to be doing something...

64.58MPH (I think I coulda gone 65, but I had to slow down for traffic ahead of me.) I was lucky to get a night with no wind to test.


This makes me wish I had larger transfer ports as well. I don;t know what I'm doing enough to mess with those, nor do I have tools capable of doing that job right. i guess I'm stuck with a 65MPH scooter. ;D

[stepthrutuner]

Good work and results, Brent. A little heavier oil mix would probably help keep things cleaner. Easiest way to increase transfer duration is to raise the high-angled boost port.

[90GTVert]

I'm happy for now and don't have spare gaskets so I'll leave my ports alone for a bit. I might move up to 40 or 45:1, but that really isn't bad for 50:1 IMO.

I forgot to mention, one of my concerns was a decrease in fuel economy. I filled up at my house, went 37.14 miles and put in 0.912 gallons of gas. That's 40.72 miles per gallon, and I was averaging 40MPG before doing this.

[2strokd]

Yep it was time for a good cleaning. Glad to see that you got the results you wanted by raising the cylinder, looks very nice .
Good job

[90GTVert]

I got another flat tire today. There was a tiny nail in it, plus a lot of cuts, and when I popped it off there were some BBs in there that looked a lot like lead shot from a shotgun. At least I had this rear tire long enough to wear a flat spot in it. From the grade of the shoulders around here. I put on the 140/70P12 that I had around in case this happened. Maybe the extra height (from 130/70P12) will boost me 0.XX MPH. lol

I just realised I missed another opportunity. That tire held pressure enough to do a burnout
before I took it off and I never even thought of it.

[2strokd]

See now i got ya there cause i woulda thought of that lol....
You gettn shot at now? Damn haters!