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08/09 tuning

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hi guys,

few questions ! ran my 08 all last season stock motor wise with a hinson clutch-full, pc clutch springs and yosh full system, just found at my first race yesterday i got left behind on the straights and the start by the other 450s all 010 models!

what did you lot change and what worked ? im thinking high comp 13.5 cp piston, yosh inlet cam and have the head polished/gas flowed, hoping the stock igniton with a remap will take this work? the bike has around 15 hours on so is due a piston any way.

just moved out of my parents so an 010 is out of the question for awhile!

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Not sure why you got left on the straights...? My 08' runs with every bike but the highly mod'd ones.

I would check to see if your clutch is slipping or not engaging correctly.

The new 2010's do not have that much more HP to leave you that easy.

Maybe try turning the throttle open more :banana: JK

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'08 and '09s are waaaaaaaaaay to rich on top, which makes them sign off quicker than any of the other bikes. Get Eddie Sinsnero (sp?) the Thumpertalk Resident Intake Expert to set you up with a Power Commander mapped for your specific mods. I had mine done by him last fall and it pulls to the moon on top.

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ok cheers ill look into the mapping more, i have played with gearing and the simple things etc already,

a better way to explain what i find is when leaving a sandy turn (i have some very deep tracks near me) the bike runs out of rpms in second but third is not quite enough, and when it does come in it rips which i why i was thinking of an inlet cam to smooth out the bottom range pull.

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The only problem with the EFI on these bikes is that you don’t have any control over the stock mapping. Every mod you do to your bike changes the air/fuel ratio and on top of that these bikes weren’t mapped right from the factory. (apparently fixed on the 2010). Changing your cams might even make the problem worse not better unless mapped correctly.

I know exactly what you mean about the bike running out of RPMs though. A good example is at my home track which has a good amount of sandy, loamy turns. There is one double in particular out of a sandy corner that was killing me. If I went wide I could hit it in 3rd no problem, but to try and take the inside line, 2nd would sign off too early, and I couldn’t get enough pull in 3rd to get the speed I needed out of the loam. On top of that, taking the inside line meant that seat bouncing it was the best option. I could do it fine in 2nd on my buddy’s YZF450 but on my bike it was kind of scary because 2nd would sign off too early if I didn’t hit it absolutely perfect and throw me forward.

Once I got the PC5 from Eddie mapped for my mods, the bike is absolutely amazing. I can hit the same corner as tight as I want and pull second all the way up the face of the jump with revs left over. Each gear pulls way longer than stock and is smooth bottom to top.

I was going to mess with the gearing but after I got the PC5 I am more than happy with the stock ratio.

If you search back through the post for Power Commander”, “PCV”, or “PC5”, you will get a lot of guys talking about this same issue. Take a look at this post from last year showing our bike stock vs. remapped on the dyno and the corresponding air fuel ratios.

http://www.thumpertalk.com/forum/showthread.php?t=767955&highlight=dyno

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You need to remap the EFI, stock it's very rich. The best method has been to buy a PCV from Eddie here at OTD Motorsports which will come with a dyno tested map for your setup. The Yosh PIM-2 sounds good as well a the Yosh MX Tuner reflashes, and while they are cheaper the results are not as good because they are not computer based and that means that every map will vary slightly ... so buyer beware.

As far as having to reflash everytime you do something, well ... that's just not true. Think of all of the current EFI systems as very accurate carbs. With the right map your fuel will be spot on (the stock '08 & '09 RMZ450's are very rich!). But back in the carb days any time you did a major change to the engine you had to rejet. Well, EFI is no different. It's just that it's a bigger deal to remap (sort of) than it is to swap some brass.

In your case with a complete yosh exhaust system on your bike you do need to remap the EFI, how you do that is up to you but it needs to be done.

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I run my PC5 and everything with a +1 on the rear. I have never tried the stock with everything on it. I think I might have to try it.

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