Glad to hear you praise the Marcelino cam mod as much. My bike (Also EFI) is at the mechanics right now getting it done...as well as extensive damage caused by theft.

I hope it will be good. I wanted a big bore but its kinda expensive to order it from the states with all the taxes and customs duty (I am in EU).

Apparantly the EFI bikes make a few more hp stock than the US bikes so maybe that are the figures I have seen.

I havent bought an exhaust yet, it seems very expensive for very little gain. Maybe I will get some effect if I make the end pipe of the stock exhaust bigger (Euro bike has different exhaust than the US bike)

 

Nikolaj, your gonna love it.. Please post your impressions on the MCM thread. I agree that the EU EFI bikes make more power than our US spec bikes. I have no idea how restrictive your stock exhaust is compared to mine - could be yours is better hence the increase in HP over US bikes... There is some great information in here about fueling your bike after modding it - I think I last saw something about this toward the end of the MCM thread..

 

Btw, how was the effect on the top end? I mean 7000 RPM and above?

Worse, better or same?

And what do you mean with "Information about fueling your bike" ? I read the entire thread several times but I dont remembe such info.

 

Well I'll let the chart speak for itself. Higher rpm range is great and pulls hard on the road.
Check out #455 on the MCM (Marcelino Cam Mod) thread.

 

Oh yeah you refer to the 02 censor eliminator. I am not sure I understand it though. I thought the 02 censor was supposed to monitor and enrichen/lean depending on what was neccesary. I.e. it adjusts itself acccordingly .Thats what Marcelino writes anyway, but maybe Jeffward has other experiences.

 

Well I don't pretend to have researched the EFI KLX or have any unique information to provide. As I understand it, the mod fools the ECU (injection controller) and runs the system at full rich. Apparently this will bring out the full potential of the mod(s) much the same way I needed the bigger #132 jet to see more benefit from my bike.

 

I will Dyno mine when i get time. 292cc with MCM intake only.

 

I think it depends how the ECU is programmed. Eliminating the O2 sensor causes the ECU to think the bike is running lean, therefore it richens up the mixture. BUT... this closed loop (O2 feedback) takes time to adjust so it can only on work at constant throttle.
Reading here (see about 1/3 down under "Operation of the engine management system."):Engine Management Basics - fearsomely complicated but not true

For varying throttle situations the ECU has a set of maps that fuel the engine depending on RPM and load (or throttle position). In the section "Mixture Strength" it's not clear if the entire set of maps is adjusted based on what in "learned" of if it's just the constant throttle map taht gets tweaked.

The problem is that we don't know how the ECU is programmed.

One thing to be careful of is that too rich a mixture can damage the cat. A good reason to use an after market pipe!

 

Okay DT175MX, that makes a lot of sense. I understand now.

Ugh. Looks like I will need a pipe after all. I really didnt want to have to buy one considering how expensive it will be to order it from the US with all the customs and toll on things from outside the EU. It only seem to add one more hp or so too, which isnt much to me.

It also pisses me off that the most popular and the cheapest exhaust, the FMF Q4 actually melts the turn signals! I like to keep stock appearance and would rather not replace the turn signals with those tiny ones that harder to see.

I was hoping that I didnt have to spend all that money for a new pipe that will provide very little benefit. Its so expensive esp. considering that a big bore kit does not cost much more. I was hoping I could perhaps just change the pipe in the stock exhaust to a bigger one like Marcelino has done.

Im running the bike now with KDX200 Snorkel, Twin Air filter and (soon) Marcelino mod. I hear some slight popping on deaccelleration (very little) and maybe it will get worse with Marcelino mod. Pop on deaccelleration means the bike is running lean right?

So maybe a PC V and a pipe is neccesary...I dont like to eliminate the 02 and trick the ECU, won´t it hurt fuel consumption a lot? I guess its better to run rich than lean?

I bought this as an economy bike, now I end up pumping a lot of money into it anyway, ****...

I am pretty new to bikes as you can hear.

 

I don't know that removing the O2 sensor will damage the cat. I only mentioned it to make people aware of a potential issue.
My gut feeling is that the KLX ECU only uses the O2 readings for steady throttle mixture adjustments so that it passes emissions tests. I suspect it leaves all the dynamic maps alone. But I geniunely do not know (and I doubt anyone else does either). Therefore I suspect opening up the airflow will result in weak running that the standard ECU does not correct.

I have decided to leave my KLX as standard. If I want more poke I'll get another bike. If there were lots of great places to ride off road in the UK I would certainly be trading the KLX for a "proper" bike. As it is I get a lot of enjoyment from the KLX on minor roads/tracks and use my MTB for serious stuff. I have also noticed that my KLX seems to feel more powerful than when I bought it (1600 miles versus 600) so it's either loosening up or I'm getting used to extracting the (limited) performance, or both.

If I was going to mod the KLX, I would talk to the local tuners who use dynos and PowerCommanders etc and get their opinions before doing anything. Seems to me that it's vital to be able to get the fuel mixture right before/for any mod.