Luke's RZ500 Tune

Luke's RZ500 Tune

How Yamaha made a 500gp replica with only 80hp I'm more of a garage junkie than a writer so this story won't ever be finished. It could be called How to Derestrict Your RZ500 or What Yamaha left out of the TSI. Not that I know enough to really explain it. A better title would be What I did for 2 years when I should have been working on my house. You just want to see pictures anyway so here they are and i'll add more till its running again. If you want to comment on my work good bad or otherwise take it to http://www.rzrd500.com/ and or http://www.yamaha-rd.com/forum/ Just remember the old saying "If you layed all the 2 stroke tuners end to end they still wouldn't reach a conclusion" My goal is to get all the midrange torque I can with stock parts. These bikes are fast as hell at high rpm's when the resonation in the exhaust overcomes the plugged up intake and transfer ducts. I think the work i've done will help throughout the range and the stock reed cages will be the restriction. I have 28 tmx mikuni's and get 30 mpg before this work was done. Most of my riding is all day trips in the mountains with friends on big bikes and gas isn't always available at 100 miles but I want my 500 to be strong in the middle without being thirsty. Wish me luck. Disclaimer: This is not a Manual!! This is the internet and its here for your entertainment!! You don't know me and I don't know sh#t from shinola!! If your foolish enough to think you know more than Yamaha about 2 strokes and want to hack on you motor thats your business don't come crying to me if you have problems. If you don't actually work on or ride but know everything and like to critize then you need to make up a stupid name, go to one of the links above and give us all a laugh!! Luther
Its February 11 2007 and the bike is close to running. These pictures aren't in good order and i'll be updating as I go. This is the big bumps for case bolt holes at the entry of the main transfer ducts for the upper cylinders. Lowers don't have them. I don't think thats effiecient.
I made a tool to measure transfer exit roof height in .5mm increments.
The other tool removes dowel sleeves.
Looking in the mirror at the front side of the main transfer next to the exhaust. Globs of aluminum are up to 3mm thick where it meets the iron on 5 of 8 ports. The corner where the flow is redirected is behind the globs so the flow should be coming almost straight at you.
I had the top end off once to try one modification at a time. (big mistake) I opened up the exhaust and ran it 1200 miles. 3 exhaust ports were clean but the upper left with bumps and globs in both main transfers looked like this. Yeah go ahead and tell me my carbs weren't right. I think the charge is short circuiting.
Looking in the main transfer the rear or seperator side goes in at an angle then turns and goes straight to the exit. The front or exhaust side goes straight then arches way back towards the exhaust to redirect the flow at the exit to the rear center of the bore. The bump in the front side where the straight meets the arch is a major restriction. Like a pinched funnel.
This is supposed to be a 30 degree secondary transfer exit.