Vortex cdi

Yes head has been ported. New valves and springs.

well poop maybe yz doctor gray has something for ya

If you haven't tried any alternative cams, get hold of an intake from an '08 and the exhaust from an '06 and use that with a CDI from an '06 as well (or the Vortex).

Another thing that will wake up the top end is to have the carb bored open to 42-44mm. Ron Hamp does this and it makes a big difference.

Always be careful porting a 5 valve Yamaha head. More people have lost power that way than gained any. The triple intake port is very tricky to get right. It's best left to the experienced tuner.

I agree with the porting , that's why a experienced tuner did this for me. As for the carb it is pretty much stock. I would think that there would be a lot of power there. I thought about converting to alky but don't know enough about these carbs to do so. Should I be looking at the carb instead of cdi at this point? By the way guys thanks for all the info!

The '03 CDI will sign off early. That's why I suggested the '06; it doesn't, and there will be a map or two in the Vortex that doesn't, either. Also the cam suggestion for the same reason. The carb bore job is a big gain, but more expensive. You might try a carb from a CRF (they're 41mm), but the gain won't be as big as the Ron Hamp mod.

As far as the cams goes , they are WEBB 963. If it's not too much trouble could you tell me more about Ron Hamp mods or put me in touch with him.

So you say the 06 cdi would be stronger on top, will it loose any other wise?

The map in the '06 CDI is considerably more civilized at the low/low-mid range, and doesn't give that massive, thrilling (but not very useful), big block Chevy kind of grunt. It pulls from mid to top much harder and some farther, though. Comparing two stock bikes, anyone would get the idea the '03 was much more powerful, and that the '06 had smoother, more controllable power at the expense of being the slower of the two. Running them side by side tells another story. The '06 is deceptively faster, and will pull away from an '03 given good enough traction.

Ron Hamp is at: http://www.ronhamp.com/

So in my type of racing ,the 06 cdi will give me more topend than the 03? With that in mind then the 06 cdi would work better for me on a bigger track and the 03 would work better on a shorter track. Yes or no?? Does that sound right?? Some of the CDI boxes I see say they fit 03-06 ?? Do I want to be looking for 06 specific?

Maybe I should try this before going to the carb?

The way I would approach running a YZ450 in a kart, the '06 CDI would work better, regardless of the track, as I would gear for the track (even if that meant going to a higher gear and using 3rd) in such a way as to run to peak power at near the end of the straight. The advantage at the very low RPM would not likely be of much use unless it were such that the track surface was so loose as to cause a major reduction in speed. But that could be determined in practice, and the CDI switched out (or an alternate map chosen) to suit.

The OEM CDI's will fit and function across wide range of years, probably '03 to '09 inclusive, but the character of each map is different. Avoid the '05, though; too soft. You might find used ones online and buy an '06, and maybe an '08. That would give you 3 to mess with for less than the Vortex. Each later unit is progressively more targeted to top end and less to low end.

But I'd still want the carb bored out.

Everything Grey is saying is correct. However, if you come across a used vortex ignition on ebay for a reasonable price, don't pass it up for an OEM one from any year. The vortex will be the best option in my opinion, especially since it comes with 10 different maps, plus can be customized if you want your own map (you need to know what you are doing to get a good map yourself). The fact that you can switch between maps with the flick of a switch while you are riding makes it worth it. Used ones are pretty cheap, like I said before, I've picked up a couple for under $140. A vortex for under $200 is definitely worth every penny.

Everything Grey is saying is correct. However, if you come across a used vortex ignition on ebay for a reasonable price, don't pass it up for an OEM one from any year. The vortex will be the best option in my opinion, especially since it comes with 10 different maps, plus can be customized if you want your own map (you need to know what you are doing to get a good map yourself). The fact that you can switch between maps with the flick of a switch while you are riding makes it worth it. Used ones are pretty cheap, like I said before, I've picked up a couple for under $140. A vortex for under $200 is definitely worth every penny.

I would agree with that, too.

Thank you guys for all the help, I will try to find something on E Bay. As for the carb, is there a bigger carb for this motor or does one need to be custom set up for my combo?

a FCR 41mx will work, I believe gray said they come on CRFs and you can find them on e-bay but some custom work would be more desireable. I would imagine if Ron Hamp got a hold of your carb you would be happy with the results but I have no idea what the cost would be.

Thanks tech24, I'm looking into the carb.

Found a vortex for a yfz450, are they the same as yz450f?

I would imagine the presets would be different and not sure about the connector

Thanks tech24, I'm looking into the carb.

Found a vortex for a yfz450, are they the same as yz450f?

The YFZ is a quad. It has a very different ignition system like the WR, based on DC power vs. AC power. Not interchangeable.

I knew you would know the answer to my question, Thank you!

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