MCX 270 Tuning/Altitude display changing on boost?

[Hillclimber]

Martens, I am no expert on the MCX system and don't have any experience with their kits below 8,000 ft.
Do I think it would make a difference? No, but I guess the guys in Sweden had the hose plumbed there for a reason and they are a lot closer to your elevation than mine.
I would call the North American MCX distributor in Prince George; if your altimeter bounces around like mine did, tell them and see what they think.

 

[Armani]

Mine have same problem, altimeter bounces all over, backfires 4-5 times before i reach the top rpm.. I disconnected the altimeter hose from the intercooler and the backfires disappaired..Nice.. but my local mcx dealer told me to connect the hose again because the engine will run lean on fuel due to mcx map,, and i`m confused!
Anyone with A/F gauge that can tell the fuel ratio with and without the altimeter pressurized??
I`m running at 1800/2000 ft

 

[loudelectronics]

Mine came with out a fitting for the baro sensor. I was having issues with lean conditions. Plugged the baro senso in and the machine is spot on for the AFR. I get the odd back fire if load is on motor and on off on throttle. Very rare thought. Mine is the 190 though.

My altimeter on the machine is all over the place while on throttle. Once I am off throttle it comes back on line.

 

[Martens199]

Yeah I tried mine unplugged. Altimeter now stays put no bouncing around. Although my backfire is still present. Maybe I will get plug it back in for the time being.
MCX is supposedly coming out with a reflash to fix the rich condition and backfire. I sent a video to them with how my sled has been backfiring, they said that's what they are addressing. Hopefully they do something about the intake backfire as well, because man is that annoying...

 

[Sharp1]

My sled has been doing the same thing. I plugged the nipple off to the inter cooler and fastened the hose to the oem computer facing down. I also got a new mapping from MCX but the sled is still backfiring this time it's worse. I think I'm hitting the rev limiter so I'm working on that now. There is just not enough snow so I might be looking at next season to get the bugs worked out. I was told the MCX is still working on the problem so hopefully there will be a fix.

 

[MCXPRESS USA]

Mcx has update map now,See your dealer for details

 

[Clinton Vick]

How do I go about getting this updated mapping installed? is it something that can be done locally at my dealer or do I have to return the MCX box to the distributor in Prince George for this? I too have an intermittent popping at 4-5000 rpm at any elevation, that is more of an annoyance than a problem. I have my clutching sorted out, I'd like to cure this and add some top end with gearing!

 

[MCXPRESS USA]

You can contact PG if you would like or send to us and we can install updated map

 

[Martens199]

Yes just mail your controller to Prince George Yamaha and note what color injectors you have.