zomby,
What model is this? And if you were going to splurge for one today, would it be the same as you have?

 

It's an innovate MTX-L. It's an all in one deal, and they're quite popular. I haven't used it yet, but I have a few buddies that do custom turbo builds, and they like them.

I bought it for one of my cars, but that turbo install hasn't happened yet, so I may as well use it for this.


http://www.innovatemotorsports.com/products/MTXL.php

 

I used an Innovate WB O2 sensor and gauge when I did my DIY (MegaSquirt) fuel injection computer (5.0L V8 stuffed into a Mazda B2200 pickup), and it worked great. You really can't tune an EFI controller without one, and having one for a carb'd setup would help immensely. Sometimes the 'butt dyno' doesn't tell the whole story or even outright lies to you. It's nice to back it up with actual AFR numbers.

 

I see this MTX-L is described as a permanent unit, but I'm assuming it could be a portable temporary installation. Any concerns with using it on a two-stroke? Where is the best place to weld on the bung?

 

Hey zomby did you double check you carb boots? perhaps you have an air leak, which would cause it to be too lean until the lid is put back on?

I had to do this twice to get it right. Installed the new jets, ran like crap. Took it apart, re did it, worked fine. Must have been the beers

 

Yes. I triple checked everything.

 

I got the wideband working on the bike, but didn't get a chance to drill and weld the bung on the pipe. That will probably be next week.
I rode today, as we're having some really nice weather, and put a couple of hours of woods in. It is better than it was, and pretty strong on top, but won't pull past 8500 and is FLAT everywhere else. So after my ride, I pulled the needle and put it back on the 3rd slot. Bingo! It now pulls everywhere, and revs to 10,000 like it should. It runs similarly with the lid on or off, so more riding is required to see which is best. Calling for nice temps again tomorrow, so I'll be back in the woods again.

 

I think the needle change from 3n to 4n netted 0.5 richer AFR on the DJ132,on my charts. All due respect, Zomby, couldn't the change to 4n have been botched and then fixed when you went back in to go 3n ? The symptoms you describe is a "robust" failure
of carburetion. Hardly the result of going one notch on the needle from standard.

 

Possibly, but I duplicated it by going back to the 4th again last night and riding it.

With all due respect, you can't expect your setup to work on all of our bikes when it's completely different. That cam mod has to be screwing with your low, mid and top end signal. You have the worst of two conditions at different times. Lot's of overlap with early intake timing, and short duration. Two conditions I'd never want at the same time.

I just wonder, if the DJ jets are really comparable to stock, maybe I should go down to a 128 as would be backed up by Richard Avatar, as his bike and mine are the same.

I compared the DJ needle to the stock one when I had it apart yesterday, just out of curiosity, and the DJ needle is a richer needle by quite a bit.

 

Just curious, when you do your dyno runs, how are you checking AFR?