I've just come across a company called "Zeeltronic" that specialises in programmable CDI units for Yamaha's.

http://www.zeeltronic.com/page/home.php

Has anybody tried one of these as they are quite expensive so just wondering are they worth the money?

Quite a few people swear by them on the DT forum. All well and good as long as you know what you're doing programming wise etc

Looked at them myself. Gives a tdr250 around 7hp and makes it feel much faster as she comes on the pipe with a bang.

The only bike that seized on our trip,  [ 12 2strokes]   had this programable ignition on it,, it had a holed piiston ,  

7 hours ago, blackhat250 said:

The only bike that seized on our trip,  [ 12 2strokes]   had this programable ignition on it,, it had a holed piiston ,  

You think that was the cause John? Or was it running lean anyway? 

Like I said earlier it all comes down to how you program it, you'd need a Dyno really and a bike that's alright set up perfectly to give a good base to start from

Yeh it was  a holed piston [ detonation]    just found out , its the second time  hes done this,,  since fitting it,, 

Thats the problem with them, they control everything. You get 3 base maps to start with when you buy one, but that doesn't they're going to work. Advance/retard ignition timing, power valve etc. You can increase the rev limit too. Dangerous if you don't have the facility to set it up

Hmmm,  it is tempting as the DTRE seems to be the less powerful DTR model,  I've always felt like the CDI is holding it back, I have the Athena 170cc kit on it which definitely improved performance but think there is more I can squeeze out of it

Remember" stock   low state of tune,[ factory]  was for longivity,   ,  high state of tune,[ race engines]  =  frequent rebuilds  , 

6 hours ago, DT RE Chris said:

Hmmm,  it is tempting as the DTRE seems to be the less powerful DTR model,  I've always felt like the CDI is holding it back, I have the Athena 170cc kit on it which definitely improved performance but think there is more I can squeeze out of it

It's not the most powerful no, however its definitely the easiest to derestrict. Once you've earthed the powervalve you're 95% there. Save a few kg's with an after market exhaust and that should really do it.

But you're right about the CDI, that's the biggest restriction after that. And if you already have the big bore kit, I'd say it's definitely the next step if you're keeping the bike long term. Just get it dyno'd and mapped correctly

The easiest to de restrict. Pah. Showing your age. Finers....

The king was the first gen powervalve engine. As quick as yours with the athena kit, properly restricted back in the day.

They flew. The rd got the pv first and could scrape 100mph if it was a good one and worked on right.

Earthing one cable to the frame? Sounds pretty easy to me. 

The re will be less restricted. The original pv was king because it made 22hp or so across the channel.

Proper power. They were a lot of fun so long as they held together. Cant argue with john on the power/riding style/reliability score.

For sure the originals were much better, tuned more as well. Every model after them had varying methods of restrictions. Some had missing boost bottles, reed switches in the clocks, powervalve cables the wrong way round. One year even has a CDI so restrictive it retards the powervalve at something silly like 8500rpm. And then there were the baffles and sound insulation in the expansion pipes!

More work involved in getting rid of all that lot